{"gene":"SFR1","run_date":"2026-06-10T07:46:31","timeline":{"discoveries":[{"year":2004,"finding":"Yeast Mei5 and Sae3 (orthologs of human SFR1/SWI5) form a ternary complex with Dmc1 and are required for assembly of Dmc1 (but not Rad51) onto chromosomes, acting as loading factors for the Dmc1 recombinase; their chromosome association requires Rad51, and they are mutually dependent with Dmc1 for localization.","method":"Genetic epistasis (sporulation, spore viability, crossing-over assays in mei5, sae3, dmc1 mutants), co-immunoprecipitation, chromatin immunofluorescence, recombination hot-spot ChIP","journal":"Cell","confidence":"High","confidence_rationale":"Tier 2 / Strong — reciprocal genetic epistasis, co-IP demonstrating ternary complex, chromosome localization by immunofluorescence, replicated in two independent labs (PMID:15620352 and PMID:15579681)","pmids":["15620352","15579681"],"is_preprint":false},{"year":2006,"finding":"The S. pombe Swi5-Sfr1 complex (ortholog of human SWI5-SFR1) stimulates Rad51 (Rhp51)- and Dmc1-mediated DNA strand exchange in vitro at substoichiometric concentrations by overcoming RPA inhibition; it preferentially stimulates the ssDNA-dependent ATPase activity of Rhp51 and increases the amount of Dmc1 bound to ssDNA.","method":"In vitro strand exchange assay, ssDNA-dependent ATPase assay, DNA binding assay with purified recombinant proteins","journal":"Nature structural & molecular biology","confidence":"High","confidence_rationale":"Tier 1 / Strong — multiple in vitro reconstitution assays with purified components; foundational biochemical paper replicated by subsequent studies","pmids":["16921379"],"is_preprint":false},{"year":2007,"finding":"In fission yeast, Swi5 localizes to the nucleus forming diffuse staining with foci; upon UV irradiation, Sfr1 forms foci colocalizing with damage-induced Rhp51 foci. Swi5/Sfr1 acts as a Rad51 mediator but processes DSBs differently from Rhp55/57: swi5Δ rhp57Δ double mutant completely abolishes UV-induced Rhp51 foci, while Rhp51 and Rhp57 (not Swi5/Sfr1) are essential for crossover production.","method":"Live fluorescence microscopy (GFP fusions), UV irradiation assays, HO endonuclease-induced DSB assay, genetic epistasis with double mutants","journal":"The EMBO journal","confidence":"High","confidence_rationale":"Tier 2 / Moderate — direct localization with functional consequence, genetic epistasis with defined phenotypic readouts, multiple orthogonal methods in one study","pmids":["17304215"],"is_preprint":false},{"year":2009,"finding":"S. cerevisiae Mei5-Sae3 complex preferentially binds single-stranded DNA, physically interacts with RPA, and relieves RPA-mediated inhibition of Dmc1 strand assimilation and DNA binding, functioning as a recombination mediator for Dmc1 assembly.","method":"In vitro strand assimilation assay, DNA binding assays, co-immunoprecipitation with RPA, purified recombinant protein biochemistry","journal":"The Journal of biological chemistry","confidence":"High","confidence_rationale":"Tier 1 / Moderate — multiple in vitro reconstitution assays with purified components, direct biochemical demonstration of mediator activity, single lab","pmids":["19270307"],"is_preprint":false},{"year":2010,"finding":"Mammalian Swi5 and Sfr1 are nuclear proteins that form a heterodimeric complex in vivo and in vitro; Swi5 interacts in vitro with Rad51. Both proteins are mutually interdependent for stability. The complex is required for HR when Rad51 is perturbed by a BRC peptide; Swi5−/− and Sfr1−/− ES cells are sensitive to ionizing radiation, camptothecin, and PARP inhibitor olaparib, show attenuated sister chromatid exchange, and increased chromosome aberrations.","method":"Co-immunoprecipitation (in vivo and in vitro), nuclear localization by microscopy, genetic knockout of mouse Swi5 and Sfr1 in ES cells, clonogenic survival assays, sister chromatid exchange assay, chromosome aberration analysis","journal":"PLoS genetics","confidence":"High","confidence_rationale":"Tier 2 / Strong — reciprocal Co-IP, clean KO with multiple defined cellular phenotypes, direct localization, multiple orthogonal methods","pmids":["20976249"],"is_preprint":false},{"year":2011,"finding":"The fission yeast Swi5-Sfr1 complex exists in a 1:1 stoichiometry (heterodimer) and adopts an extremely elongated dogleg-shaped structure in solution (high frictional ratio f/f0 = 2.0), as determined by SAXS and analytical ultracentrifugation; topology mapping with Fab fragments suggests the complex fits into the groove of the Rad51 filament.","method":"Small-angle X-ray scattering (SAXS), analytical ultracentrifugation, electrospray ionization mass spectrometry, Fab-fragment topology mapping","journal":"The Journal of biological chemistry","confidence":"High","confidence_rationale":"Tier 1 / Moderate — multiple biophysical methods (SAXS, AUC, MS) in one study establishing stoichiometry and solution structure","pmids":["22033972"],"is_preprint":false},{"year":2011,"finding":"The budding yeast Mei5-Sae3 complex preferentially binds fork-like DNA substrates over 3'-overhang, ssDNA, or dsDNA; DNA binding activity is conferred by the Mei5 subunit. Mei5-Sae3 interacts with Rad51 through the N-terminal domain of Mei5. Unlike Rad52, Mei5-Sae3 lacks recombination mediator activity for Rad51 and lacks ssDNA annealing activity.","method":"Electrophoretic mobility shift assay (EMSA) with purified proteins, DNA substrate binding assays, co-immunoprecipitation/pulldown with Rad51","journal":"DNA repair","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — multiple direct biochemical assays with purified components, single lab, clearly distinguishes Mei5-Sae3 activities from Rad52","pmids":["21543267"],"is_preprint":false},{"year":2012,"finding":"Mouse Swi5-Sfr1 heterodimer (1:1 stoichiometry) physically interacts with Rad51 and stabilizes the Rad51-ssDNA presynaptic filament, stimulating homologous DNA pairing; neither Swi5 nor Sfr1 alone can substitute for the complex. The RSfp (rodent Sfr1 proline-rich) motif in Sfr1 acts as a negative regulatory element.","method":"Biophysical characterization (analytical ultracentrifugation), in vitro Rad51-mediated DNA pairing assay, presynaptic filament stability assay, domain mutagenesis (RSfp deletion)","journal":"Nucleic acids research","confidence":"High","confidence_rationale":"Tier 1 / Moderate — in vitro reconstitution with purified mammalian proteins, stoichiometry determination, mutagenesis of regulatory domain, multiple orthogonal methods in one study","pmids":["22492707"],"is_preprint":false},{"year":2012,"finding":"Crystal structure of the fission yeast Swi5-Sfr1 complex (C-terminal core domain of Sfr1 with Swi5) reveals a parallel coiled-coil heterodimer joined by two leucine-zipper motifs and a bundle, forming a sharply kinked elongated crescent shape suited for binding within the helical groove of the Rad51 filament; the N-terminal region of Sfr1 provides a Rad51-binding interface.","method":"X-ray crystallography (2.3 Å resolution), mutagenesis-guided functional validation","journal":"Structure","confidence":"High","confidence_rationale":"Tier 1 / Strong — crystal structure at 2.3 Å with domain mutagenesis functional validation, provides atomic-resolution mechanistic insight","pmids":["22405003"],"is_preprint":false},{"year":2013,"finding":"SWI5-SFR1 facilitates ADP release from the RAD51 presynaptic filament, thereby maintaining the ATP-bound (catalytically active) state of the filament; this is distinct from simply blocking ATP hydrolysis. SWI5-SFR1 also enhances ATP hydrolysis by ssDNA-bound RAD51.","method":"Optical tweezers single-molecule experiments, biochemical ATPase assays, ADP release kinetics with purified proteins","journal":"Nucleic acids research","confidence":"High","confidence_rationale":"Tier 1 / Moderate — single-molecule optical tweezers and ensemble biochemical assays, defines catalytic mechanism at molecular level, single lab","pmids":["24078249"],"is_preprint":false},{"year":2013,"finding":"Swi5-Sfr1 promotes more perpendicular alignment of nucleobases (coplanar alignment) in the Rad51/ssDNA presynaptic filament, as measured by flow linear dichroism spectroscopy; this structural change is mediated through interaction with the Rad51 filament rather than directly with DNA, as a ΔN-Sfr1 mutant lacking DNA affinity still induces the same base orientation change.","method":"Flow linear dichroism spectroscopy, N-terminal deletion mutant of Sfr1","journal":"Nucleic acids research","confidence":"Medium","confidence_rationale":"Tier 1 / Weak — novel biophysical method demonstrating filament structural change, single lab, single method","pmids":["24304898"],"is_preprint":false},{"year":2013,"finding":"In fission yeast, Swi5-Sfr1 is a mediator that loads Dmc1 onto RPA-coated ssDNA and a direct activator of Dmc1 strand exchange; in contrast, Rad22 (fission yeast Rad52) inhibits Dmc1 by competing for binding to RPA-coated ssDNA, while activating Rad51.","method":"In vitro strand exchange assay with purified Dmc1, Swi5-Sfr1, Rad22, and RPA; competitive binding assays","journal":"Genes & development","confidence":"High","confidence_rationale":"Tier 1 / Moderate — in vitro reconstitution with purified components, competitive assays distinguishing mediator vs. activator roles, single lab with multiple assays","pmids":["24186976"],"is_preprint":false},{"year":2013,"finding":"Human SFR1 physically interacts with estrogen receptor alpha (ERα): interaction initially identified by yeast two-hybrid and confirmed by co-immunoprecipitation in mammalian cells. SFR1 co-localizes with ERα in the nucleus, potentiates ERα transcriptional activity (ligand-dependent and -independent), occupies ER-target gene promoters by ChIP, and SFR1 knockdown diminishes ER transcriptional activity.","method":"Yeast two-hybrid screen, co-immunoprecipitation, mammalian one-hybrid assay, co-localization by microscopy, ChIP, siRNA knockdown","journal":"PloS one","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — reciprocal interaction confirmation by Co-IP and mammalian one-hybrid, ChIP localization, siRNA functional validation; single lab","pmids":["23874500"],"is_preprint":false},{"year":2013,"finding":"In fission yeast, Rrp1 and Rrp2 interact with Swi5 (two-hybrid), form co-localizing MMS-induced nuclear foci, and function epistatically with Swi5 and Srs2 (but independently of Rad57), placing them in the Swi5/Sfr1-dependent branch of HR.","method":"Yeast two-hybrid, fluorescence microscopy (co-localizing foci), genetic epistasis analysis","journal":"Nucleic acids research","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — yeast two-hybrid interaction plus genetic epistasis with defined pathway placement, single lab","pmids":["23828040"],"is_preprint":false},{"year":2016,"finding":"The C-terminal domain of mouse SWI5 is required for physical interaction with RAD51; SWI5-SFR1 preferentially associates with oligomeric RAD51. RAD51 interaction-defective mutants of SWI5-SFR1 abolish stimulation of RAD51 recombinase activity, establishing that physical interaction is indispensable for functional stimulation (trimeric RAD51-SWI5-SFR1 complex).","method":"Pull-down/co-immunoprecipitation with domain deletion and point mutants, in vitro Rad51 strand exchange assay, analytical ultracentrifugation","journal":"Nucleic acids research","confidence":"High","confidence_rationale":"Tier 1 / Moderate — mutagenesis plus in vitro reconstitution assays, interaction-defective mutants directly link binding to function, multiple methods in one study","pmids":["27131790"],"is_preprint":false},{"year":2018,"finding":"Mouse Swi5-Sfr1 (mS5S1) stimulates Rad51 filament assembly by reducing RAD51 dissociation from filaments, reducing the effective nucleation size from 3 to 2 RAD51 molecules; fission yeast Swi5-Sfr1 similarly reduces SpRad51 disassembly rate to maintain stable filaments, demonstrating a conserved mechanism.","method":"Single-molecule tethered particle motion (TPM), single-molecule FRET (smFRET), mouse and fission yeast Rad51 with purified Swi5-Sfr1","journal":"Proceedings of the National Academy of Sciences of the United States of America","confidence":"High","confidence_rationale":"Tier 1 / Strong — two independent single-molecule methods (TPM and smFRET), tested in two species demonstrating conservation, rigorous kinetic analysis","pmids":["30297419"],"is_preprint":false},{"year":2019,"finding":"In S. cerevisiae, Mei5-Sae3 (ortholog of SFR1-SWI5) has independent roles: Rad51 function as an accessory factor for Dmc1 filament stability, while the partner Rad51 also functions independently in promoting filament stability. A gain-of-function dmc1-E157D mutant bypasses the requirement for Mei5-Sae3, forms longer filaments prone to aberrant recombination. Mei5-Sae3 limits filament length to prevent genome rearrangements.","method":"Genetic analysis (gain-of-function mutant, double mutants), super-resolution microscopy (STORM), analysis of recombination intermediates","journal":"PLoS genetics","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — gain-of-function genetics combined with super-resolution imaging and molecular recombination intermediate analysis, single lab","pmids":["31790385"],"is_preprint":false},{"year":2020,"finding":"Two distinct sites within the intrinsically disordered N-terminus of Sfr1 (Sfr1N) cooperatively bind Rad51; deletion of this domain impairs Rad51 stimulation in vitro and causes DNA damage sensitivity in cells. Swi5-Sfr1 and Rad55-Rad57 can form a higher-order complex and collaboratively stimulate Rad51 in S. pombe.","method":"NMR, biochemical binding assays (purified proteins), in vitro Rad51 stimulation assays, yeast genetic sensitivity assays, co-immunoprecipitation (higher-order complex)","journal":"eLife","confidence":"High","confidence_rationale":"Tier 1 / Moderate — NMR structural analysis of Sfr1N, in vitro reconstitution, mutagenesis with both in vitro and in vivo validation, multiple orthogonal methods","pmids":["32204793"],"is_preprint":false},{"year":2021,"finding":"Fission yeast Swi5 and Sfr1 are phosphorylated during meiosis at specific sites identified by mass spectrometry. Phosphomimetic mutations at these sites render Swi5-Sfr1 only partially functional; phospho-blocking mutations do not impair function.","method":"Mass spectrometry of purified complex from meiotic cells, mutagenesis (phosphomimetic and phospho-blocking mutants), functional assays in yeast","journal":"Genes","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — MS identification of phosphosites plus mutagenesis with functional readout, single lab; full mechanistic significance remains unclear per authors","pmids":["34208949"],"is_preprint":false},{"year":2023,"finding":"Phosphorylation of five residues within the intrinsically disordered domain of fission yeast Sfr1 (by an unspecified kinase, likely CDK based on motifs) regulates its interaction with Rad51; a phosphomimetic Swi5-Sfr1 mutant is defective in both physical and functional interaction with Rad51, resulting in DNA repair deficiency. A phospho-blocking mutant also shows DNA damage sensitivity, indicating that regulated (reversible) phosphorylation is required.","method":"Biochemical reconstitution with phosphomimetic/phospho-blocking mutants, in vitro binding and strand exchange assays, yeast genetic DNA damage sensitivity assays","journal":"The Journal of biological chemistry","confidence":"High","confidence_rationale":"Tier 1 / Moderate — biochemical reconstitution with defined phosphomimetic mutants linking PTM to functional interaction, validated in vivo, multiple orthogonal methods","pmids":["37330173"],"is_preprint":false},{"year":2023,"finding":"Swi5-Sfr1 and Hop2-Mnd1 stimulate Dmc1 filament assembly by distinct mechanisms: Hop2-Mnd1 enhances the Dmc1 binding rate (nucleation), while Swi5-Sfr1 specifically reduces the Dmc1 dissociation rate during nucleation (~2-fold); the two complexes act additively when combined.","method":"Single-molecule FRET (smFRET), tethered particle motion (TPM), order-of-addition experiments with purified proteins","journal":"Nucleic acids research","confidence":"High","confidence_rationale":"Tier 1 / Moderate — single-molecule experiments (smFRET and TPM) directly measuring kinetic parameters, mechanistically distinguishes two accessory factors, rigorous quantitative analysis","pmids":["37395447"],"is_preprint":false},{"year":2024,"finding":"CDK phosphorylates fission yeast Sfr1 at multiple sites in its N-terminal disordered domain during meiotic prophase; phospho-mimetic sfr1-7D inhibits Rad51 binding and chromosome loading, decreasing interhomolog recombination. Non-phosphorylatable sfr1-7A alters Rad51 dynamics at late prophase and exacerbates chromatin segregation defects when combined with dbl2 deletion. The N-terminal disordered domain of Sfr1 serves as a CDK-regulated platform.","method":"Genetic mutant analysis (phosphomimetic sfr1-7D and non-phosphorylatable sfr1-7A), chromosome immunofluorescence (Rad51 loading), cytology (chromosome segregation), biochemical validation","journal":"The EMBO journal","confidence":"High","confidence_rationale":"Tier 2 / Moderate — multiple genetic mutants with defined biochemical and cytological phenotypes, identifies CDK as the writer kinase, multiple orthogonal readouts","pmids":["39174851"],"is_preprint":false},{"year":2024,"finding":"Mei5-Sae3 stabilizes Dmc1 nucleating clusters (2–3 molecules) on naked ssDNA by preferentially reducing Dmc1 dissociation rates, and also stimulates Dmc1 assembly on RPA-coated ssDNA; an intermediate with coexisting Dmc1 and RPA on ssDNA was observed before RPA dissociation, suggesting Mei5-Sae3 mediates Dmc1 binding by stabilizing nucleating clusters to promote RPA displacement.","method":"Single-molecule FRET (smFRET), colocalization single-molecule spectroscopy (CoSMoS), GFP-labeled RPA displacement assay, purified recombinant proteins","journal":"Nucleic acids research","confidence":"High","confidence_rationale":"Tier 1 / Moderate — two complementary single-molecule methods with direct visualization of RPA displacement intermediate, rigorous kinetic analysis","pmids":["39275989"],"is_preprint":false},{"year":2024,"finding":"Arg97 of Mei5 (conserved in human SFR1) is critical for complex formation with Sae3 and for Dmc1 assembly; substitution of Arg117 or Lys133 leads to production of a C-terminally truncated Mei5 protein specifically during meiosis (not mitosis), suggesting posttranslational processing unique to meiotic regulation of Dmc1-mediated recombination.","method":"Site-directed mutagenesis of Mei5 basic residues, co-immunoprecipitation (complex formation), Western blot (truncated protein), yeast meiosis vs. mitosis comparison","journal":"Genes to cells","confidence":"Medium","confidence_rationale":"Tier 2 / Moderate — mutagenesis combined with Co-IP and protein analysis identifying meiosis-specific processing, single lab","pmids":["38924305"],"is_preprint":false},{"year":2024,"finding":"Swi5-Sfr1 regulates Dmc1- and Rad51-driven strand exchange via distinct mechanisms: for Rad51, it facilitates the C1→C2 transition in strand exchange and releases ssDNA from C2 (activator role); for Dmc1, it enhances association with ssDNA by promoting filament nucleus formation (mediator role), unlike its activator role with Rad51.","method":"Real-time in vitro strand exchange assay with fission yeast Dmc1 and Rad51, kinetic analysis of three-stranded intermediates (C1, C2), purified recombinant proteins","journal":"Nucleic acids research","confidence":"High","confidence_rationale":"Tier 1 / Moderate — real-time in vitro reconstitution with defined intermediates, kinetic modeling distinguishing activator vs. mediator mechanisms for two different recombinases","pmids":["39340300"],"is_preprint":false},{"year":2025,"finding":"Mouse SWI5-SFR1 reduces the dissociation probability of RAD51 during filament extension, promoting more uniform filament growth; step-size analysis shows RAD51 assembles predominantly as octamers, and in the presence of SWI5-SFR1 the distribution shifts toward tetramers, indicating SWI5-SFR1 modulates the oligomeric state of RAD51 in solution to facilitate extension and stabilize DNA binding.","method":"Single-molecule tethered particle motion (TPM) with step-size analysis, purified mouse RAD51 and SWI5-SFR1","journal":"Nucleic acids research","confidence":"Medium","confidence_rationale":"Tier 1 / Weak — single-molecule reconstitution with quantitative step-size analysis, single lab, single method, no orthogonal validation yet","pmids":["40682818"],"is_preprint":false},{"year":2025,"finding":"Budding yeast Mei5-Sae3 stabilizes Dmc1 filaments in both active (ATP-bound) and inactive (ADP-bound) conformations; it specifically stabilizes the active filament form without inhibiting ATP hydrolysis—indeed it increases ATP hydrolysis—unlike calcium, AMP-PNP, or the E157D mutation which stabilize filaments by blocking hydrolysis. This demonstrates Mei5-Sae3's filament stabilization does not depend on alteration of the hydrolytic cycle.","method":"In vitro filament stability assays, ATPase assays, nucleotide cofactor substitution experiments, dmc1-E157D gain-of-function comparison, purified recombinant proteins","journal":"Nucleic acids research","confidence":"High","confidence_rationale":"Tier 1 / Moderate — multiple in vitro reconstitution assays with mechanistic comparisons to other filament stabilizers, ATPase measurements, rigorous controls distinguishing mechanisms","pmids":["41206037"],"is_preprint":false}],"current_model":"SFR1 (human)/Sfr1 forms a conserved heterodimeric complex with SWI5 that functions as a dual-activity auxiliary factor for the RAD51 recombinase: the complex binds within the groove of the RAD51 presynaptic filament via its elongated crescent-shaped structure, stabilizes RAD51 filaments by reducing RAD51 dissociation and promoting ADP release (maintaining the catalytically active ATP-bound state), shifts RAD51 oligomerization toward smaller units to facilitate filament extension, and—in meiosis—acts as both a mediator loading Dmc1 onto RPA-coated ssDNA and a direct activator of Dmc1 strand exchange; the intrinsically disordered N-terminus of Sfr1 contains two cooperative Rad51-binding sites and serves as a CDK-regulated phosphorylation platform that downregulates complex function at late meiotic prophase, ensuring timely resolution of recombination intermediates."},"narrative":{"mechanistic_narrative":"SFR1 (Sfr1/Mei5) is a conserved auxiliary factor for the eukaryotic RAD51/Dmc1 recombinases that promotes homologous recombination by acting on presynaptic filament dynamics [PMID:20976249, PMID:22492707, PMID:30297419]. It functions exclusively as a heterodimer with SWI5 (Sae3), assembling in a 1:1 stoichiometry into an extremely elongated, sharply kinked crescent-shaped molecule—built from a Swi5-Sfr1 parallel coiled-coil core joined by leucine zippers—whose geometry fits the helical groove of the RAD51 filament; the two subunits are mutually interdependent for stability and neither alone substitutes for the complex [PMID:22033972, PMID:22492707, PMID:22405003, PMID:20976249]. The complex physically engages RAD51 through the C-terminal domain of SWI5 and through two cooperative binding sites in the intrinsically disordered N-terminus of Sfr1, and this physical interaction is indispensable for stimulating recombinase activity [PMID:27131790, PMID:32204793]. Mechanistically, SWI5-SFR1 stabilizes the RAD51-ssDNA presynaptic filament by reducing RAD51 dissociation, lowering the effective nucleation size, and shifting RAD51 oligomerization toward smaller units to favor uniform filament extension [PMID:30297419, PMID:40682818]; it maintains the catalytically active ATP-bound filament state by facilitating ADP release rather than by blocking ATP hydrolysis [PMID:24078249, PMID:41206037], and it functions as a direct activator of RAD51 strand exchange by driving the C1→C2 transition and releasing ssDNA [PMID:39340300]. In meiosis the complex serves a dual role with the Dmc1 recombinase—loading Dmc1 onto RPA-coated ssDNA as a mediator and stabilizing nucleating Dmc1 clusters to promote RPA displacement [PMID:24186976, PMID:39275989, PMID:39340300]—and its activity is downregulated by CDK phosphorylation of the Sfr1 disordered N-terminus during late meiotic prophase, which inhibits RAD51 binding and chromosome loading to ensure timely resolution of recombination intermediates [PMID:37330173, PMID:39174851]. Loss of SWI5 or SFR1 sensitizes cells to ionizing radiation, camptothecin, and PARP inhibition with attenuated sister chromatid exchange and increased chromosome aberrations [PMID:20976249]. Human SFR1 additionally interacts with estrogen receptor alpha and potentiates its transcriptional activity [PMID:23874500].","teleology":[{"year":2004,"claim":"Established that the Mei5-Sae3 (SFR1-SWI5) complex is a dedicated loading factor for the meiotic recombinase Dmc1, defining its first cellular function as distinct from the generic Rad51 pathway.","evidence":"Genetic epistasis, co-IP, and chromosome immunofluorescence in budding yeast meiosis","pmids":["15620352","15579681"],"confidence":"High","gaps":["Did not establish the biochemical mechanism of Dmc1 loading","Mitotic/Rad51-directed role not addressed"]},{"year":2006,"claim":"Showed the complex acts catalytically (substoichiometric) in vitro to overcome RPA inhibition of strand exchange, framing it as a recombination accessory factor for both Rad51 and Dmc1.","evidence":"In vitro strand exchange and ATPase assays with purified fission yeast proteins","pmids":["16921379"],"confidence":"High","gaps":["Did not resolve whether stimulation acts on filament assembly versus catalysis","No structural basis for RAD51 engagement"]},{"year":2007,"claim":"Placed Swi5-Sfr1 in a distinct HR sub-branch from Rhp55/57 in cells, showing partially redundant but mechanistically separate mediator roles.","evidence":"Live microscopy of damage-induced foci and genetic epistasis with double mutants in fission yeast","pmids":["17304215"],"confidence":"High","gaps":["Molecular basis for branch distinction not defined","Crossover-specific roles not assigned to the complex"]},{"year":2009,"claim":"Demonstrated direct biochemical mediator activity: Mei5-Sae3 binds ssDNA, interacts with RPA, and relieves RPA inhibition of Dmc1, providing a mechanism for the genetic loading phenotype.","evidence":"In vitro strand assimilation, DNA binding, and RPA co-IP with purified budding yeast proteins","pmids":["19270307"],"confidence":"High","gaps":["Did not visualize the RPA-to-Dmc1 handoff intermediate","Stoichiometry of the active species unresolved"]},{"year":2011,"claim":"Defined the solution architecture as a 1:1 elongated dogleg heterodimer suited to fit the Rad51 filament groove, linking shape to function.","evidence":"SAXS, analytical ultracentrifugation, mass spectrometry, and Fab topology mapping; species comparison resolving DNA-binding versus stabilization roles","pmids":["22033972","21543267"],"confidence":"High","gaps":["No atomic-resolution structure yet","Filament-groove docking inferred, not directly observed"]},{"year":2012,"claim":"Extended the mechanism to mammals and provided atomic detail: the heterodimer stabilizes the Rad51 presynaptic filament and adopts a kinked crescent core via leucine-zipper-joined coiled coils, with the Sfr1 N-terminus providing the Rad51 interface.","evidence":"In vitro DNA pairing and filament stability assays with mouse proteins plus 2.3 Å crystal structure of the fission yeast core domain","pmids":["22492707","22405003"],"confidence":"High","gaps":["N-terminal disordered region not resolved crystallographically","RSfp regulatory motif mechanism in mammals undefined"]},{"year":2013,"claim":"Resolved the catalytic mechanism of filament stabilization as ADP release maintaining the active ATP-bound state, and distinguished mediator (Dmc1) from activator roles, while also revealing a non-recombination role in ERα transcription.","evidence":"Optical tweezers single-molecule and ensemble ATPase assays; flow linear dichroism; competitive strand exchange with Rad22; and Y2H/Co-IP/ChIP for human SFR1-ERα","pmids":["24078249","24304898","24186976","23874500","23828040"],"confidence":"High","gaps":["ERα transcriptional role (Medium) characterized in a single lab without reciprocal validation","Physiological significance of the transcriptional role versus recombination role unresolved"]},{"year":2016,"claim":"Established that direct physical contact via the SWI5 C-terminus is indispensable for functional stimulation, ruling out an indirect or DNA-only mechanism.","evidence":"Interaction-defective domain/point mutants combined with in vitro strand exchange and AUC of mouse proteins","pmids":["27131790"],"confidence":"High","gaps":["Did not map the reciprocal RAD51 interface","Trimeric complex geometry not determined structurally"]},{"year":2018,"claim":"Quantified the conserved kinetic mechanism: the complex reduces RAD51 nucleation size and dissociation, stabilizing filaments across mouse and fission yeast.","evidence":"Single-molecule TPM and smFRET with two-species comparison","pmids":["30297419"],"confidence":"High","gaps":["Did not address oligomeric state changes during extension","Meiotic Dmc1 kinetics not measured in the same framework"]},{"year":2019,"claim":"Showed in vivo that Mei5-Sae3 limits Dmc1 filament length to prevent aberrant recombination, linking filament regulation to genome stability.","evidence":"Gain-of-function dmc1-E157D genetics, double mutants, and STORM super-resolution imaging in budding yeast","pmids":["31790385"],"confidence":"Medium","gaps":["Mechanism of length limitation not biochemically reconstituted","Single-lab genetic analysis"]},{"year":2020,"claim":"Mapped two cooperative Rad51-binding sites in the intrinsically disordered Sfr1 N-terminus and showed the complex can cooperate with Rad55-Rad57 in a higher-order assembly.","evidence":"NMR, biochemical binding/stimulation assays, yeast sensitivity assays, and Co-IP in fission yeast","pmids":["32204793"],"confidence":"High","gaps":["Architecture of the Swi5-Sfr1/Rad55-Rad57 super-complex undefined","Whether mammalian SFR1 has the same dual sites untested here"]},{"year":2021,"claim":"Identified meiotic phosphorylation of Swi5 and Sfr1, with phosphomimetic mutants partially impairing function, opening a regulatory dimension to complex activity.","evidence":"Mass spectrometry of complex from meiotic cells plus phosphomimetic/phospho-blocking mutagenesis with functional assays","pmids":["34208949"],"confidence":"Medium","gaps":["Writer kinase not identified at this stage","Full mechanistic significance left unresolved by authors"]},{"year":2023,"claim":"Linked phosphorylation of the Sfr1 disordered domain directly to regulated Rad51 binding, showing reversible (not merely added) phosphorylation tunes the interaction.","evidence":"Biochemical reconstitution with phosphomimetic/phospho-blocking mutants, binding and strand exchange assays, and yeast damage sensitivity","pmids":["37330173"],"confidence":"High","gaps":["Identity of the kinase inferred from motifs, not proven","Dephosphorylation/phosphatase not addressed"]},{"year":2024,"claim":"Defined the meiotic regulatory circuit: CDK phosphorylates the Sfr1 N-terminal disordered platform during prophase to downregulate Rad51 binding/loading and tune interhomolog recombination timing, with separable activator (Rad51) versus mediator (Dmc1) mechanisms and meiosis-specific Mei5 processing.","evidence":"sfr1-7D/7A genetic mutants with chromosome immunofluorescence and cytology; real-time strand exchange kinetics (C1/C2 intermediates); smFRET/CoSMoS RPA-displacement assays; Mei5 basic-residue mutagenesis with Co-IP","pmids":["39174851","39340300","39275989","38924305"],"confidence":"High","gaps":["Whether CDK regulation is conserved in mammalian SFR1 untested","Meiosis-specific Mei5 truncation (Medium) and its protease not defined"]},{"year":2025,"claim":"Refined the filament mechanism by showing the complex modulates RAD51 oligomeric state (octamer→tetramer) in solution to promote uniform extension, and demonstrated that stabilization of the active Dmc1/Rad51 filament is independent of altering the ATP hydrolytic cycle.","evidence":"Single-molecule TPM step-size analysis with mouse proteins; in vitro filament stability and ATPase assays with nucleotide and E157D comparisons in budding yeast","pmids":["40682818","41206037"],"confidence":"High","gaps":["Step-size/oligomer model (Medium) rests on a single method without orthogonal validation","Structural basis for oligomer modulation unknown"]},{"year":null,"claim":"Whether the meiotic CDK-phosphorylation regulatory mechanism and the human ERα transcriptional role of SFR1 are conserved and functionally integrated with its recombination function in mammals remains unresolved.","evidence":"","pmids":[],"confidence":"Medium","gaps":["No mammalian in vivo test of CDK regulation of SFR1","Relationship between SFR1's transcriptional and recombination roles uncharacterized","No atomic structure of the trimeric RAD51-SWI5-SFR1 complex"]}],"mechanism_profile":{"molecular_activity":[{"term_id":"GO:0003677","term_label":"DNA binding","supporting_discovery_ids":[3,6]},{"term_id":"GO:0098772","term_label":"molecular function regulator activity","supporting_discovery_ids":[1,7,9,14,15,24]},{"term_id":"GO:0060090","term_label":"molecular adaptor activity","supporting_discovery_ids":[3,11,22]},{"term_id":"GO:0140110","term_label":"transcription regulator activity","supporting_discovery_ids":[12]}],"localization":[{"term_id":"GO:0005634","term_label":"nucleus","supporting_discovery_ids":[2,4,12]},{"term_id":"GO:0005694","term_label":"chromosome","supporting_discovery_ids":[0,21]}],"pathway":[{"term_id":"R-HSA-73894","term_label":"DNA Repair","supporting_discovery_ids":[4,17]},{"term_id":"R-HSA-1474165","term_label":"Reproduction","supporting_discovery_ids":[0,11,21]},{"term_id":"R-HSA-74160","term_label":"Gene expression (Transcription)","supporting_discovery_ids":[12]}],"complexes":["SWI5-SFR1 (Mei5-Sae3) heterodimer","RAD51-SWI5-SFR1 trimeric complex","Swi5-Sfr1/Rad55-Rad57 higher-order complex"],"partners":["SWI5","RAD51","DMC1","RPA","ESR1","RAD55","RAD57"],"other_free_text":[]}},"prefetch_data":{"uniprot":{"accession":"Q86XK3","full_name":"Swi5-dependent recombination DNA repair protein 1 homolog","aliases":["Meiosis protein 5 homolog"],"length_aa":245,"mass_kda":28.3,"function":"Component of the SWI5-SFR1 complex, a complex required for double-strand break repair via homologous recombination (PubMed:21252223). Acts as a transcriptional modulator for ESR1 (PubMed:23874500)","subcellular_location":"Nucleus","url":"https://www.uniprot.org/uniprotkb/Q86XK3/entry"},"depmap":{"release":"DepMap","has_data":true,"is_common_essential":false,"resolved_as":"","url":"https://depmap.org/portal/gene/SFR1","classification":"Not Classified","n_dependent_lines":119,"n_total_lines":1208,"dependency_fraction":0.09850993377483444},"opencell":{"profiled":false,"resolved_as":"","ensg_id":"","cell_line_id":"","localizations":[],"interactors":[],"url":"https://opencell.sf.czbiohub.org/search/SFR1","total_profiled":1310},"omim":[{"mim_id":"616528","title":"SWI5 HOMOLOGOUS RECOMBINATION REPAIR PROTEIN; SWI5","url":"https://www.omim.org/entry/616528"},{"mim_id":"616527","title":"SWI5-DEPENDENT HOMOLOGOUS RECOMBINATION REPAIR PROTEIN 1; SFR1","url":"https://www.omim.org/entry/616527"}],"hpa":{"profiled":true,"resolved_as":"","reliability":"Supported","locations":[{"location":"Nucleoli rim","reliability":"Supported"},{"location":"Nucleoplasm","reliability":"Additional"},{"location":"Centrosome","reliability":"Additional"}],"tissue_specificity":"Low tissue specificity","tissue_distribution":"Detected in all","driving_tissues":[],"url":"https://www.proteinatlas.org/search/SFR1"},"hgnc":{"alias_symbol":["MEI5","bA373N18.1","FLJ41960"],"prev_symbol":["C10orf78","MEIR5"]},"alphafold":{"accession":"Q86XK3","domains":[{"cath_id":"1.20.5","chopping":"149-184","consensus_level":"medium","plddt":94.9647,"start":149,"end":184},{"cath_id":"1.10.10","chopping":"186-245","consensus_level":"medium","plddt":88.0523,"start":186,"end":245}],"viewer_url":"https://alphafold.ebi.ac.uk/entry/Q86XK3","model_url":"https://alphafold.ebi.ac.uk/files/AF-Q86XK3-F1-model_v6.cif","pae_url":"https://alphafold.ebi.ac.uk/files/AF-Q86XK3-F1-predicted_aligned_error_v6.png","plddt_mean":66.94},"mouse_models":{"mgi_url":"https://www.informatics.jax.org/marker/summary?nomen=SFR1","jax_strain_url":"https://www.jax.org/strain/search?query=SFR1"},"sequence":{"accession":"Q86XK3","fasta_url":"https://rest.uniprot.org/uniprotkb/Q86XK3.fasta","uniprot_url":"https://www.uniprot.org/uniprotkb/Q86XK3/entry","alphafold_viewer_url":"https://alphafold.ebi.ac.uk/entry/Q86XK3"}},"corpus_meta":[{"pmid":"15620352","id":"PMC_15620352","title":"A 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their chromosome association requires Rad51, and they are mutually dependent with Dmc1 for localization.\",\n      \"method\": \"Genetic epistasis (sporulation, spore viability, crossing-over assays in mei5, sae3, dmc1 mutants), co-immunoprecipitation, chromatin immunofluorescence, recombination hot-spot ChIP\",\n      \"journal\": \"Cell\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 / Strong — reciprocal genetic epistasis, co-IP demonstrating ternary complex, chromosome localization by immunofluorescence, replicated in two independent labs (PMID:15620352 and PMID:15579681)\",\n      \"pmids\": [\"15620352\", \"15579681\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2006,\n      \"finding\": \"The S. pombe Swi5-Sfr1 complex (ortholog of human SWI5-SFR1) stimulates Rad51 (Rhp51)- and Dmc1-mediated DNA strand exchange in vitro at substoichiometric concentrations by overcoming RPA inhibition; it preferentially stimulates the ssDNA-dependent ATPase activity of Rhp51 and increases the amount of Dmc1 bound to ssDNA.\",\n      \"method\": \"In vitro strand exchange assay, ssDNA-dependent ATPase assay, DNA binding assay with purified recombinant proteins\",\n      \"journal\": \"Nature structural & molecular biology\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1 / Strong — multiple in vitro reconstitution assays with purified components; foundational biochemical paper replicated by subsequent studies\",\n      \"pmids\": [\"16921379\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2007,\n      \"finding\": \"In fission yeast, Swi5 localizes to the nucleus forming diffuse staining with foci; upon UV irradiation, Sfr1 forms foci colocalizing with damage-induced Rhp51 foci. Swi5/Sfr1 acts as a Rad51 mediator but processes DSBs differently from Rhp55/57: swi5Δ rhp57Δ double mutant completely abolishes UV-induced Rhp51 foci, while Rhp51 and Rhp57 (not Swi5/Sfr1) are essential for crossover production.\",\n      \"method\": \"Live fluorescence microscopy (GFP fusions), UV irradiation assays, HO endonuclease-induced DSB assay, genetic epistasis with double mutants\",\n      \"journal\": \"The EMBO journal\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — direct localization with functional consequence, genetic epistasis with defined phenotypic readouts, multiple orthogonal methods in one study\",\n      \"pmids\": [\"17304215\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2009,\n      \"finding\": \"S. cerevisiae Mei5-Sae3 complex preferentially binds single-stranded DNA, physically interacts with RPA, and relieves RPA-mediated inhibition of Dmc1 strand assimilation and DNA binding, functioning as a recombination mediator for Dmc1 assembly.\",\n      \"method\": \"In vitro strand assimilation assay, DNA binding assays, co-immunoprecipitation with RPA, purified recombinant protein biochemistry\",\n      \"journal\": \"The Journal of biological chemistry\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1 / Moderate — multiple in vitro reconstitution assays with purified components, direct biochemical demonstration of mediator activity, single lab\",\n      \"pmids\": [\"19270307\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2010,\n      \"finding\": \"Mammalian Swi5 and Sfr1 are nuclear proteins that form a heterodimeric complex in vivo and in vitro; Swi5 interacts in vitro with Rad51. Both proteins are mutually interdependent for stability. The complex is required for HR when Rad51 is perturbed by a BRC peptide; Swi5−/− and Sfr1−/− ES cells are sensitive to ionizing radiation, camptothecin, and PARP inhibitor olaparib, show attenuated sister chromatid exchange, and increased chromosome aberrations.\",\n      \"method\": \"Co-immunoprecipitation (in vivo and in vitro), nuclear localization by microscopy, genetic knockout of mouse Swi5 and Sfr1 in ES cells, clonogenic survival assays, sister chromatid exchange assay, chromosome aberration analysis\",\n      \"journal\": \"PLoS genetics\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 / Strong — reciprocal Co-IP, clean KO with multiple defined cellular phenotypes, direct localization, multiple orthogonal methods\",\n      \"pmids\": [\"20976249\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2011,\n      \"finding\": \"The fission yeast Swi5-Sfr1 complex exists in a 1:1 stoichiometry (heterodimer) and adopts an extremely elongated dogleg-shaped structure in solution (high frictional ratio f/f0 = 2.0), as determined by SAXS and analytical ultracentrifugation; topology mapping with Fab fragments suggests the complex fits into the groove of the Rad51 filament.\",\n      \"method\": \"Small-angle X-ray scattering (SAXS), analytical ultracentrifugation, electrospray ionization mass spectrometry, Fab-fragment topology mapping\",\n      \"journal\": \"The Journal of biological chemistry\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1 / Moderate — multiple biophysical methods (SAXS, AUC, MS) in one study establishing stoichiometry and solution structure\",\n      \"pmids\": [\"22033972\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2011,\n      \"finding\": \"The budding yeast Mei5-Sae3 complex preferentially binds fork-like DNA substrates over 3'-overhang, ssDNA, or dsDNA; DNA binding activity is conferred by the Mei5 subunit. Mei5-Sae3 interacts with Rad51 through the N-terminal domain of Mei5. Unlike Rad52, Mei5-Sae3 lacks recombination mediator activity for Rad51 and lacks ssDNA annealing activity.\",\n      \"method\": \"Electrophoretic mobility shift assay (EMSA) with purified proteins, DNA substrate binding assays, co-immunoprecipitation/pulldown with Rad51\",\n      \"journal\": \"DNA repair\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — multiple direct biochemical assays with purified components, single lab, clearly distinguishes Mei5-Sae3 activities from Rad52\",\n      \"pmids\": [\"21543267\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2012,\n      \"finding\": \"Mouse Swi5-Sfr1 heterodimer (1:1 stoichiometry) physically interacts with Rad51 and stabilizes the Rad51-ssDNA presynaptic filament, stimulating homologous DNA pairing; neither Swi5 nor Sfr1 alone can substitute for the complex. The RSfp (rodent Sfr1 proline-rich) motif in Sfr1 acts as a negative regulatory element.\",\n      \"method\": \"Biophysical characterization (analytical ultracentrifugation), in vitro Rad51-mediated DNA pairing assay, presynaptic filament stability assay, domain mutagenesis (RSfp deletion)\",\n      \"journal\": \"Nucleic acids research\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1 / Moderate — in vitro reconstitution with purified mammalian proteins, stoichiometry determination, mutagenesis of regulatory domain, multiple orthogonal methods in one study\",\n      \"pmids\": [\"22492707\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2012,\n      \"finding\": \"Crystal structure of the fission yeast Swi5-Sfr1 complex (C-terminal core domain of Sfr1 with Swi5) reveals a parallel coiled-coil heterodimer joined by two leucine-zipper motifs and a bundle, forming a sharply kinked elongated crescent shape suited for binding within the helical groove of the Rad51 filament; the N-terminal region of Sfr1 provides a Rad51-binding interface.\",\n      \"method\": \"X-ray crystallography (2.3 Å resolution), mutagenesis-guided functional validation\",\n      \"journal\": \"Structure\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1 / Strong — crystal structure at 2.3 Å with domain mutagenesis functional validation, provides atomic-resolution mechanistic insight\",\n      \"pmids\": [\"22405003\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2013,\n      \"finding\": \"SWI5-SFR1 facilitates ADP release from the RAD51 presynaptic filament, thereby maintaining the ATP-bound (catalytically active) state of the filament; this is distinct from simply blocking ATP hydrolysis. SWI5-SFR1 also enhances ATP hydrolysis by ssDNA-bound RAD51.\",\n      \"method\": \"Optical tweezers single-molecule experiments, biochemical ATPase assays, ADP release kinetics with purified proteins\",\n      \"journal\": \"Nucleic acids research\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1 / Moderate — single-molecule optical tweezers and ensemble biochemical assays, defines catalytic mechanism at molecular level, single lab\",\n      \"pmids\": [\"24078249\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2013,\n      \"finding\": \"Swi5-Sfr1 promotes more perpendicular alignment of nucleobases (coplanar alignment) in the Rad51/ssDNA presynaptic filament, as measured by flow linear dichroism spectroscopy; this structural change is mediated through interaction with the Rad51 filament rather than directly with DNA, as a ΔN-Sfr1 mutant lacking DNA affinity still induces the same base orientation change.\",\n      \"method\": \"Flow linear dichroism spectroscopy, N-terminal deletion mutant of Sfr1\",\n      \"journal\": \"Nucleic acids research\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 1 / Weak — novel biophysical method demonstrating filament structural change, single lab, single method\",\n      \"pmids\": [\"24304898\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2013,\n      \"finding\": \"In fission yeast, Swi5-Sfr1 is a mediator that loads Dmc1 onto RPA-coated ssDNA and a direct activator of Dmc1 strand exchange; in contrast, Rad22 (fission yeast Rad52) inhibits Dmc1 by competing for binding to RPA-coated ssDNA, while activating Rad51.\",\n      \"method\": \"In vitro strand exchange assay with purified Dmc1, Swi5-Sfr1, Rad22, and RPA; competitive binding assays\",\n      \"journal\": \"Genes & development\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1 / Moderate — in vitro reconstitution with purified components, competitive assays distinguishing mediator vs. activator roles, single lab with multiple assays\",\n      \"pmids\": [\"24186976\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2013,\n      \"finding\": \"Human SFR1 physically interacts with estrogen receptor alpha (ERα): interaction initially identified by yeast two-hybrid and confirmed by co-immunoprecipitation in mammalian cells. SFR1 co-localizes with ERα in the nucleus, potentiates ERα transcriptional activity (ligand-dependent and -independent), occupies ER-target gene promoters by ChIP, and SFR1 knockdown diminishes ER transcriptional activity.\",\n      \"method\": \"Yeast two-hybrid screen, co-immunoprecipitation, mammalian one-hybrid assay, co-localization by microscopy, ChIP, siRNA knockdown\",\n      \"journal\": \"PloS one\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — reciprocal interaction confirmation by Co-IP and mammalian one-hybrid, ChIP localization, siRNA functional validation; single lab\",\n      \"pmids\": [\"23874500\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2013,\n      \"finding\": \"In fission yeast, Rrp1 and Rrp2 interact with Swi5 (two-hybrid), form co-localizing MMS-induced nuclear foci, and function epistatically with Swi5 and Srs2 (but independently of Rad57), placing them in the Swi5/Sfr1-dependent branch of HR.\",\n      \"method\": \"Yeast two-hybrid, fluorescence microscopy (co-localizing foci), genetic epistasis analysis\",\n      \"journal\": \"Nucleic acids research\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — yeast two-hybrid interaction plus genetic epistasis with defined pathway placement, single lab\",\n      \"pmids\": [\"23828040\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2016,\n      \"finding\": \"The C-terminal domain of mouse SWI5 is required for physical interaction with RAD51; SWI5-SFR1 preferentially associates with oligomeric RAD51. RAD51 interaction-defective mutants of SWI5-SFR1 abolish stimulation of RAD51 recombinase activity, establishing that physical interaction is indispensable for functional stimulation (trimeric RAD51-SWI5-SFR1 complex).\",\n      \"method\": \"Pull-down/co-immunoprecipitation with domain deletion and point mutants, in vitro Rad51 strand exchange assay, analytical ultracentrifugation\",\n      \"journal\": \"Nucleic acids research\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1 / Moderate — mutagenesis plus in vitro reconstitution assays, interaction-defective mutants directly link binding to function, multiple methods in one study\",\n      \"pmids\": [\"27131790\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2018,\n      \"finding\": \"Mouse Swi5-Sfr1 (mS5S1) stimulates Rad51 filament assembly by reducing RAD51 dissociation from filaments, reducing the effective nucleation size from 3 to 2 RAD51 molecules; fission yeast Swi5-Sfr1 similarly reduces SpRad51 disassembly rate to maintain stable filaments, demonstrating a conserved mechanism.\",\n      \"method\": \"Single-molecule tethered particle motion (TPM), single-molecule FRET (smFRET), mouse and fission yeast Rad51 with purified Swi5-Sfr1\",\n      \"journal\": \"Proceedings of the National Academy of Sciences of the United States of America\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1 / Strong — two independent single-molecule methods (TPM and smFRET), tested in two species demonstrating conservation, rigorous kinetic analysis\",\n      \"pmids\": [\"30297419\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2019,\n      \"finding\": \"In S. cerevisiae, Mei5-Sae3 (ortholog of SFR1-SWI5) has independent roles: Rad51 function as an accessory factor for Dmc1 filament stability, while the partner Rad51 also functions independently in promoting filament stability. A gain-of-function dmc1-E157D mutant bypasses the requirement for Mei5-Sae3, forms longer filaments prone to aberrant recombination. Mei5-Sae3 limits filament length to prevent genome rearrangements.\",\n      \"method\": \"Genetic analysis (gain-of-function mutant, double mutants), super-resolution microscopy (STORM), analysis of recombination intermediates\",\n      \"journal\": \"PLoS genetics\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — gain-of-function genetics combined with super-resolution imaging and molecular recombination intermediate analysis, single lab\",\n      \"pmids\": [\"31790385\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2020,\n      \"finding\": \"Two distinct sites within the intrinsically disordered N-terminus of Sfr1 (Sfr1N) cooperatively bind Rad51; deletion of this domain impairs Rad51 stimulation in vitro and causes DNA damage sensitivity in cells. Swi5-Sfr1 and Rad55-Rad57 can form a higher-order complex and collaboratively stimulate Rad51 in S. pombe.\",\n      \"method\": \"NMR, biochemical binding assays (purified proteins), in vitro Rad51 stimulation assays, yeast genetic sensitivity assays, co-immunoprecipitation (higher-order complex)\",\n      \"journal\": \"eLife\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1 / Moderate — NMR structural analysis of Sfr1N, in vitro reconstitution, mutagenesis with both in vitro and in vivo validation, multiple orthogonal methods\",\n      \"pmids\": [\"32204793\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2021,\n      \"finding\": \"Fission yeast Swi5 and Sfr1 are phosphorylated during meiosis at specific sites identified by mass spectrometry. Phosphomimetic mutations at these sites render Swi5-Sfr1 only partially functional; phospho-blocking mutations do not impair function.\",\n      \"method\": \"Mass spectrometry of purified complex from meiotic cells, mutagenesis (phosphomimetic and phospho-blocking mutants), functional assays in yeast\",\n      \"journal\": \"Genes\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — MS identification of phosphosites plus mutagenesis with functional readout, single lab; full mechanistic significance remains unclear per authors\",\n      \"pmids\": [\"34208949\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2023,\n      \"finding\": \"Phosphorylation of five residues within the intrinsically disordered domain of fission yeast Sfr1 (by an unspecified kinase, likely CDK based on motifs) regulates its interaction with Rad51; a phosphomimetic Swi5-Sfr1 mutant is defective in both physical and functional interaction with Rad51, resulting in DNA repair deficiency. A phospho-blocking mutant also shows DNA damage sensitivity, indicating that regulated (reversible) phosphorylation is required.\",\n      \"method\": \"Biochemical reconstitution with phosphomimetic/phospho-blocking mutants, in vitro binding and strand exchange assays, yeast genetic DNA damage sensitivity assays\",\n      \"journal\": \"The Journal of biological chemistry\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1 / Moderate — biochemical reconstitution with defined phosphomimetic mutants linking PTM to functional interaction, validated in vivo, multiple orthogonal methods\",\n      \"pmids\": [\"37330173\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2023,\n      \"finding\": \"Swi5-Sfr1 and Hop2-Mnd1 stimulate Dmc1 filament assembly by distinct mechanisms: Hop2-Mnd1 enhances the Dmc1 binding rate (nucleation), while Swi5-Sfr1 specifically reduces the Dmc1 dissociation rate during nucleation (~2-fold); the two complexes act additively when combined.\",\n      \"method\": \"Single-molecule FRET (smFRET), tethered particle motion (TPM), order-of-addition experiments with purified proteins\",\n      \"journal\": \"Nucleic acids research\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1 / Moderate — single-molecule experiments (smFRET and TPM) directly measuring kinetic parameters, mechanistically distinguishes two accessory factors, rigorous quantitative analysis\",\n      \"pmids\": [\"37395447\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2024,\n      \"finding\": \"CDK phosphorylates fission yeast Sfr1 at multiple sites in its N-terminal disordered domain during meiotic prophase; phospho-mimetic sfr1-7D inhibits Rad51 binding and chromosome loading, decreasing interhomolog recombination. Non-phosphorylatable sfr1-7A alters Rad51 dynamics at late prophase and exacerbates chromatin segregation defects when combined with dbl2 deletion. The N-terminal disordered domain of Sfr1 serves as a CDK-regulated platform.\",\n      \"method\": \"Genetic mutant analysis (phosphomimetic sfr1-7D and non-phosphorylatable sfr1-7A), chromosome immunofluorescence (Rad51 loading), cytology (chromosome segregation), biochemical validation\",\n      \"journal\": \"The EMBO journal\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — multiple genetic mutants with defined biochemical and cytological phenotypes, identifies CDK as the writer kinase, multiple orthogonal readouts\",\n      \"pmids\": [\"39174851\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2024,\n      \"finding\": \"Mei5-Sae3 stabilizes Dmc1 nucleating clusters (2–3 molecules) on naked ssDNA by preferentially reducing Dmc1 dissociation rates, and also stimulates Dmc1 assembly on RPA-coated ssDNA; an intermediate with coexisting Dmc1 and RPA on ssDNA was observed before RPA dissociation, suggesting Mei5-Sae3 mediates Dmc1 binding by stabilizing nucleating clusters to promote RPA displacement.\",\n      \"method\": \"Single-molecule FRET (smFRET), colocalization single-molecule spectroscopy (CoSMoS), GFP-labeled RPA displacement assay, purified recombinant proteins\",\n      \"journal\": \"Nucleic acids research\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1 / Moderate — two complementary single-molecule methods with direct visualization of RPA displacement intermediate, rigorous kinetic analysis\",\n      \"pmids\": [\"39275989\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2024,\n      \"finding\": \"Arg97 of Mei5 (conserved in human SFR1) is critical for complex formation with Sae3 and for Dmc1 assembly; substitution of Arg117 or Lys133 leads to production of a C-terminally truncated Mei5 protein specifically during meiosis (not mitosis), suggesting posttranslational processing unique to meiotic regulation of Dmc1-mediated recombination.\",\n      \"method\": \"Site-directed mutagenesis of Mei5 basic residues, co-immunoprecipitation (complex formation), Western blot (truncated protein), yeast meiosis vs. mitosis comparison\",\n      \"journal\": \"Genes to cells\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 2 / Moderate — mutagenesis combined with Co-IP and protein analysis identifying meiosis-specific processing, single lab\",\n      \"pmids\": [\"38924305\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2024,\n      \"finding\": \"Swi5-Sfr1 regulates Dmc1- and Rad51-driven strand exchange via distinct mechanisms: for Rad51, it facilitates the C1→C2 transition in strand exchange and releases ssDNA from C2 (activator role); for Dmc1, it enhances association with ssDNA by promoting filament nucleus formation (mediator role), unlike its activator role with Rad51.\",\n      \"method\": \"Real-time in vitro strand exchange assay with fission yeast Dmc1 and Rad51, kinetic analysis of three-stranded intermediates (C1, C2), purified recombinant proteins\",\n      \"journal\": \"Nucleic acids research\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1 / Moderate — real-time in vitro reconstitution with defined intermediates, kinetic modeling distinguishing activator vs. mediator mechanisms for two different recombinases\",\n      \"pmids\": [\"39340300\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2025,\n      \"finding\": \"Mouse SWI5-SFR1 reduces the dissociation probability of RAD51 during filament extension, promoting more uniform filament growth; step-size analysis shows RAD51 assembles predominantly as octamers, and in the presence of SWI5-SFR1 the distribution shifts toward tetramers, indicating SWI5-SFR1 modulates the oligomeric state of RAD51 in solution to facilitate extension and stabilize DNA binding.\",\n      \"method\": \"Single-molecule tethered particle motion (TPM) with step-size analysis, purified mouse RAD51 and SWI5-SFR1\",\n      \"journal\": \"Nucleic acids research\",\n      \"confidence\": \"Medium\",\n      \"confidence_rationale\": \"Tier 1 / Weak — single-molecule reconstitution with quantitative step-size analysis, single lab, single method, no orthogonal validation yet\",\n      \"pmids\": [\"40682818\"],\n      \"is_preprint\": false\n    },\n    {\n      \"year\": 2025,\n      \"finding\": \"Budding yeast Mei5-Sae3 stabilizes Dmc1 filaments in both active (ATP-bound) and inactive (ADP-bound) conformations; it specifically stabilizes the active filament form without inhibiting ATP hydrolysis—indeed it increases ATP hydrolysis—unlike calcium, AMP-PNP, or the E157D mutation which stabilize filaments by blocking hydrolysis. This demonstrates Mei5-Sae3's filament stabilization does not depend on alteration of the hydrolytic cycle.\",\n      \"method\": \"In vitro filament stability assays, ATPase assays, nucleotide cofactor substitution experiments, dmc1-E157D gain-of-function comparison, purified recombinant proteins\",\n      \"journal\": \"Nucleic acids research\",\n      \"confidence\": \"High\",\n      \"confidence_rationale\": \"Tier 1 / Moderate — multiple in vitro reconstitution assays with mechanistic comparisons to other filament stabilizers, ATPase measurements, rigorous controls distinguishing mechanisms\",\n      \"pmids\": [\"41206037\"],\n      \"is_preprint\": false\n    }\n  ],\n  \"current_model\": \"SFR1 (human)/Sfr1 forms a conserved heterodimeric complex with SWI5 that functions as a dual-activity auxiliary factor for the RAD51 recombinase: the complex binds within the groove of the RAD51 presynaptic filament via its elongated crescent-shaped structure, stabilizes RAD51 filaments by reducing RAD51 dissociation and promoting ADP release (maintaining the catalytically active ATP-bound state), shifts RAD51 oligomerization toward smaller units to facilitate filament extension, and—in meiosis—acts as both a mediator loading Dmc1 onto RPA-coated ssDNA and a direct activator of Dmc1 strand exchange; the intrinsically disordered N-terminus of Sfr1 contains two cooperative Rad51-binding sites and serves as a CDK-regulated phosphorylation platform that downregulates complex function at late meiotic prophase, ensuring timely resolution of recombination intermediates.\"\n}\n```","stage2_raw":"{\n  \"mechanistic_narrative\": \"SFR1 (Sfr1/Mei5) is a conserved auxiliary factor for the eukaryotic RAD51/Dmc1 recombinases that promotes homologous recombination by acting on presynaptic filament dynamics [#4, #7, #15]. It functions exclusively as a heterodimer with SWI5 (Sae3), assembling in a 1:1 stoichiometry into an extremely elongated, sharply kinked crescent-shaped molecule\\u2014built from a Swi5-Sfr1 parallel coiled-coil core joined by leucine zippers\\u2014whose geometry fits the helical groove of the RAD51 filament; the two subunits are mutually interdependent for stability and neither alone substitutes for the complex [#5, #7, #8, #4]. The complex physically engages RAD51 through the C-terminal domain of SWI5 and through two cooperative binding sites in the intrinsically disordered N-terminus of Sfr1, and this physical interaction is indispensable for stimulating recombinase activity [#14, #17]. Mechanistically, SWI5-SFR1 stabilizes the RAD51-ssDNA presynaptic filament by reducing RAD51 dissociation, lowering the effective nucleation size, and shifting RAD51 oligomerization toward smaller units to favor uniform filament extension [#15, #25]; it maintains the catalytically active ATP-bound filament state by facilitating ADP release rather than by blocking ATP hydrolysis [#9, #26], and it functions as a direct activator of RAD51 strand exchange by driving the C1\\u2192C2 transition and releasing ssDNA [#24]. In meiosis the complex serves a dual role with the Dmc1 recombinase\\u2014loading Dmc1 onto RPA-coated ssDNA as a mediator and stabilizing nucleating Dmc1 clusters to promote RPA displacement [#11, #22, #24]\\u2014and its activity is downregulated by CDK phosphorylation of the Sfr1 disordered N-terminus during late meiotic prophase, which inhibits RAD51 binding and chromosome loading to ensure timely resolution of recombination intermediates [#19, #21]. Loss of SWI5 or SFR1 sensitizes cells to ionizing radiation, camptothecin, and PARP inhibition with attenuated sister chromatid exchange and increased chromosome aberrations [#4]. Human SFR1 additionally interacts with estrogen receptor alpha and potentiates its transcriptional activity [#12].\",\n  \"teleology\": [\n    {\n      \"year\": 2004,\n      \"claim\": \"Established that the Mei5-Sae3 (SFR1-SWI5) complex is a dedicated loading factor for the meiotic recombinase Dmc1, defining its first cellular function as distinct from the generic Rad51 pathway.\",\n      \"evidence\": \"Genetic epistasis, co-IP, and chromosome immunofluorescence in budding yeast meiosis\",\n      \"pmids\": [\"15620352\", \"15579681\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Did not establish the biochemical mechanism of Dmc1 loading\", \"Mitotic/Rad51-directed role not addressed\"]\n    },\n    {\n      \"year\": 2006,\n      \"claim\": \"Showed the complex acts catalytically (substoichiometric) in vitro to overcome RPA inhibition of strand exchange, framing it as a recombination accessory factor for both Rad51 and Dmc1.\",\n      \"evidence\": \"In vitro strand exchange and ATPase assays with purified fission yeast proteins\",\n      \"pmids\": [\"16921379\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Did not resolve whether stimulation acts on filament assembly versus catalysis\", \"No structural basis for RAD51 engagement\"]\n    },\n    {\n      \"year\": 2007,\n      \"claim\": \"Placed Swi5-Sfr1 in a distinct HR sub-branch from Rhp55/57 in cells, showing partially redundant but mechanistically separate mediator roles.\",\n      \"evidence\": \"Live microscopy of damage-induced foci and genetic epistasis with double mutants in fission yeast\",\n      \"pmids\": [\"17304215\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Molecular basis for branch distinction not defined\", \"Crossover-specific roles not assigned to the complex\"]\n    },\n    {\n      \"year\": 2009,\n      \"claim\": \"Demonstrated direct biochemical mediator activity: Mei5-Sae3 binds ssDNA, interacts with RPA, and relieves RPA inhibition of Dmc1, providing a mechanism for the genetic loading phenotype.\",\n      \"evidence\": \"In vitro strand assimilation, DNA binding, and RPA co-IP with purified budding yeast proteins\",\n      \"pmids\": [\"19270307\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Did not visualize the RPA-to-Dmc1 handoff intermediate\", \"Stoichiometry of the active species unresolved\"]\n    },\n    {\n      \"year\": 2011,\n      \"claim\": \"Defined the solution architecture as a 1:1 elongated dogleg heterodimer suited to fit the Rad51 filament groove, linking shape to function.\",\n      \"evidence\": \"SAXS, analytical ultracentrifugation, mass spectrometry, and Fab topology mapping; species comparison resolving DNA-binding versus stabilization roles\",\n      \"pmids\": [\"22033972\", \"21543267\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"No atomic-resolution structure yet\", \"Filament-groove docking inferred, not directly observed\"]\n    },\n    {\n      \"year\": 2012,\n      \"claim\": \"Extended the mechanism to mammals and provided atomic detail: the heterodimer stabilizes the Rad51 presynaptic filament and adopts a kinked crescent core via leucine-zipper-joined coiled coils, with the Sfr1 N-terminus providing the Rad51 interface.\",\n      \"evidence\": \"In vitro DNA pairing and filament stability assays with mouse proteins plus 2.3 \\u00c5 crystal structure of the fission yeast core domain\",\n      \"pmids\": [\"22492707\", \"22405003\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"N-terminal disordered region not resolved crystallographically\", \"RSfp regulatory motif mechanism in mammals undefined\"]\n    },\n    {\n      \"year\": 2013,\n      \"claim\": \"Resolved the catalytic mechanism of filament stabilization as ADP release maintaining the active ATP-bound state, and distinguished mediator (Dmc1) from activator roles, while also revealing a non-recombination role in ER\\u03b1 transcription.\",\n      \"evidence\": \"Optical tweezers single-molecule and ensemble ATPase assays; flow linear dichroism; competitive strand exchange with Rad22; and Y2H/Co-IP/ChIP for human SFR1-ER\\u03b1\",\n      \"pmids\": [\"24078249\", \"24304898\", \"24186976\", \"23874500\", \"23828040\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"ER\\u03b1 transcriptional role (Medium) characterized in a single lab without reciprocal validation\", \"Physiological significance of the transcriptional role versus recombination role unresolved\"]\n    },\n    {\n      \"year\": 2016,\n      \"claim\": \"Established that direct physical contact via the SWI5 C-terminus is indispensable for functional stimulation, ruling out an indirect or DNA-only mechanism.\",\n      \"evidence\": \"Interaction-defective domain/point mutants combined with in vitro strand exchange and AUC of mouse proteins\",\n      \"pmids\": [\"27131790\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Did not map the reciprocal RAD51 interface\", \"Trimeric complex geometry not determined structurally\"]\n    },\n    {\n      \"year\": 2018,\n      \"claim\": \"Quantified the conserved kinetic mechanism: the complex reduces RAD51 nucleation size and dissociation, stabilizing filaments across mouse and fission yeast.\",\n      \"evidence\": \"Single-molecule TPM and smFRET with two-species comparison\",\n      \"pmids\": [\"30297419\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Did not address oligomeric state changes during extension\", \"Meiotic Dmc1 kinetics not measured in the same framework\"]\n    },\n    {\n      \"year\": 2019,\n      \"claim\": \"Showed in vivo that Mei5-Sae3 limits Dmc1 filament length to prevent aberrant recombination, linking filament regulation to genome stability.\",\n      \"evidence\": \"Gain-of-function dmc1-E157D genetics, double mutants, and STORM super-resolution imaging in budding yeast\",\n      \"pmids\": [\"31790385\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Mechanism of length limitation not biochemically reconstituted\", \"Single-lab genetic analysis\"]\n    },\n    {\n      \"year\": 2020,\n      \"claim\": \"Mapped two cooperative Rad51-binding sites in the intrinsically disordered Sfr1 N-terminus and showed the complex can cooperate with Rad55-Rad57 in a higher-order assembly.\",\n      \"evidence\": \"NMR, biochemical binding/stimulation assays, yeast sensitivity assays, and Co-IP in fission yeast\",\n      \"pmids\": [\"32204793\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Architecture of the Swi5-Sfr1/Rad55-Rad57 super-complex undefined\", \"Whether mammalian SFR1 has the same dual sites untested here\"]\n    },\n    {\n      \"year\": 2021,\n      \"claim\": \"Identified meiotic phosphorylation of Swi5 and Sfr1, with phosphomimetic mutants partially impairing function, opening a regulatory dimension to complex activity.\",\n      \"evidence\": \"Mass spectrometry of complex from meiotic cells plus phosphomimetic/phospho-blocking mutagenesis with functional assays\",\n      \"pmids\": [\"34208949\"],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"Writer kinase not identified at this stage\", \"Full mechanistic significance left unresolved by authors\"]\n    },\n    {\n      \"year\": 2023,\n      \"claim\": \"Linked phosphorylation of the Sfr1 disordered domain directly to regulated Rad51 binding, showing reversible (not merely added) phosphorylation tunes the interaction.\",\n      \"evidence\": \"Biochemical reconstitution with phosphomimetic/phospho-blocking mutants, binding and strand exchange assays, and yeast damage sensitivity\",\n      \"pmids\": [\"37330173\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Identity of the kinase inferred from motifs, not proven\", \"Dephosphorylation/phosphatase not addressed\"]\n    },\n    {\n      \"year\": 2024,\n      \"claim\": \"Defined the meiotic regulatory circuit: CDK phosphorylates the Sfr1 N-terminal disordered platform during prophase to downregulate Rad51 binding/loading and tune interhomolog recombination timing, with separable activator (Rad51) versus mediator (Dmc1) mechanisms and meiosis-specific Mei5 processing.\",\n      \"evidence\": \"sfr1-7D/7A genetic mutants with chromosome immunofluorescence and cytology; real-time strand exchange kinetics (C1/C2 intermediates); smFRET/CoSMoS RPA-displacement assays; Mei5 basic-residue mutagenesis with Co-IP\",\n      \"pmids\": [\"39174851\", \"39340300\", \"39275989\", \"38924305\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Whether CDK regulation is conserved in mammalian SFR1 untested\", \"Meiosis-specific Mei5 truncation (Medium) and its protease not defined\"]\n    },\n    {\n      \"year\": 2025,\n      \"claim\": \"Refined the filament mechanism by showing the complex modulates RAD51 oligomeric state (octamer\\u2192tetramer) in solution to promote uniform extension, and demonstrated that stabilization of the active Dmc1/Rad51 filament is independent of altering the ATP hydrolytic cycle.\",\n      \"evidence\": \"Single-molecule TPM step-size analysis with mouse proteins; in vitro filament stability and ATPase assays with nucleotide and E157D comparisons in budding yeast\",\n      \"pmids\": [\"40682818\", \"41206037\"],\n      \"confidence\": \"High\",\n      \"gaps\": [\"Step-size/oligomer model (Medium) rests on a single method without orthogonal validation\", \"Structural basis for oligomer modulation unknown\"]\n    },\n    {\n      \"year\": null,\n      \"claim\": \"Whether the meiotic CDK-phosphorylation regulatory mechanism and the human ER\\u03b1 transcriptional role of SFR1 are conserved and functionally integrated with its recombination function in mammals remains unresolved.\",\n      \"evidence\": \"\",\n      \"pmids\": [],\n      \"confidence\": \"Medium\",\n      \"gaps\": [\"No mammalian in vivo test of CDK regulation of SFR1\", \"Relationship between SFR1's transcriptional and recombination roles uncharacterized\", \"No atomic structure of the trimeric RAD51-SWI5-SFR1 complex\"]\n    }\n  ],\n  \"mechanism_profile\": {\n    \"molecular_activity\": [\n      {\"term_id\": \"GO:0003677\", \"supporting_discovery_ids\": [3, 6]},\n      {\"term_id\": \"GO:0098772\", \"supporting_discovery_ids\": [1, 7, 9, 14, 15, 24]},\n      {\"term_id\": \"GO:0060090\", \"supporting_discovery_ids\": [3, 11, 22]},\n      {\"term_id\": \"GO:0140110\", \"supporting_discovery_ids\": [12]}\n    ],\n    \"localization\": [\n      {\"term_id\": \"GO:0005634\", \"supporting_discovery_ids\": [2, 4, 12]},\n      {\"term_id\": \"GO:0005694\", \"supporting_discovery_ids\": [0, 21]}\n    ],\n    \"pathway\": [\n      {\"term_id\": \"R-HSA-73894\", \"supporting_discovery_ids\": [4, 17]},\n      {\"term_id\": \"R-HSA-1474165\", \"supporting_discovery_ids\": [0, 11, 21]},\n      {\"term_id\": \"R-HSA-74160\", \"supporting_discovery_ids\": [12]}\n    ],\n    \"complexes\": [\"SWI5-SFR1 (Mei5-Sae3) heterodimer\", \"RAD51-SWI5-SFR1 trimeric complex\", \"Swi5-Sfr1/Rad55-Rad57 higher-order complex\"],\n    \"partners\": [\"SWI5\", \"RAD51\", \"DMC1\", \"RPA\", \"ESR1\", \"RAD55\", \"RAD57\"],\n    \"other_free_text\": []\n  }\n}","audit_flag":null,"evaluation":{"pairwise":"win","faith_supported":7,"faith_total":7,"faith_pct":100.0}}