mus81

Existing Annotations Review

GO Term	Evidence	Action	Reason
GO:0008821 crossover junction DNA endonuclease activity	IBA GO_REF:0000033	ACCEPT	Summary: Phylogenetic (IBA) propagation of the core molecular function of Mus81 across the orthology group. This is the central catalytic activity of Mus81-Eme1, directly demonstrated experimentally in S. pombe, so the IBA call is well-founded. Reason: Core molecular function, corroborated by direct experimental evidence (IDA/IMP) in S. pombe. Supporting Evidence: PMID:11719193 We report that Mus81 and an associated protein Eme1 are components of an endonuclease that resolves Holliday junctions into linear duplex products.
GO:0048476 Holliday junction resolvase complex	IBA GO_REF:0000033	ACCEPT	Summary: Phylogenetic propagation of complex membership. Mus81 is part of the Mus81-Eme1 heterodimeric resolvase, established experimentally in S. pombe. Reason: Core cellular component, corroborated by direct experimental IDA/IPI evidence for the Mus81-Eme1 complex. Supporting Evidence: PMID:11719193 These findings constitute strong evidence that Mus81 and Eme1 are subunits of a nuclear Holliday junction resolvase.
GO:0000712 resolution of meiotic recombination intermediates	IBA GO_REF:0000033	ACCEPT	Summary: Phylogenetic propagation of a core meiotic biological process. Mus81-Eme1 resolves meiotic joint molecules/Holliday junctions at a late step of meiotic recombination, directly shown in S. pombe. Reason: Core meiotic process, corroborated by direct and mutant-phenotype evidence in S. pombe. Supporting Evidence: PMID:11719193 Mus81 and Eme1 are required during meiosis at a late step of meiotic recombination.
GO:0000727 double-strand break repair via break-induced replication	IBA GO_REF:0000033	KEEP AS NON CORE	Summary: IBA propagation of a role in break-induced/recombination-dependent replication. Mus81-Eme1 processes collapsed replication forks and the joint molecules formed during recombination-dependent fork restart, consistent with a BIR-related role, though the direct S. pombe evidence is for fork processing rather than canonical BIR. Plausible but a peripheral, non-core aspect. Reason: Consistent with Mus81 fork/joint-molecule processing but not the central function; BIR involvement is inferred rather than directly demonstrated for S. pombe Mus81. Supporting Evidence: PMID:28586299 The heterodimeric structure-specific DNA endonuclease Mus81-Eme1 can cleave both stalled RFs and recombination intermediates, including D-loops and Holliday junctions
GO:0031573 mitotic intra-S DNA damage checkpoint signaling	IBA GO_REF:0000033	ACCEPT	Summary: IBA propagation of a role in the intra-S DNA damage checkpoint. In S. pombe Mus81 acts downstream of Cds1 in checkpoint-dependent replication slowing, corroborated by direct mutant analysis. Reason: Corroborated by IMP evidence (PMID:19037101) placing Mus81 in the Cds1-dependent S-phase DNA damage checkpoint pathway. Supporting Evidence: PMID:19037101 We have identified proteins downstream of Cds1 required for checkpoint-dependant slowing, including the structure-specific endonuclease Mus81 and the helicase Rqh1
GO:0000712 resolution of meiotic recombination intermediates	IEA GO_REF:0000117	ACCEPT	Summary: ARBA machine-learning electronic annotation duplicating the experimentally supported core meiotic process. Accurate but redundant with the IDA/IMP/IBA calls for the same term. Reason: Correct core process, redundant with stronger experimental evidence in S. pombe. Supporting Evidence: PMID:11719193 Mus81 and Eme1 are required during meiosis at a late step of meiotic recombination.
GO:0000724 double-strand break repair via homologous recombination	IEA GO_REF:0000117	ACCEPT	Summary: ARBA electronic annotation for DSB repair via HR. This is supported experimentally in S. pombe, where Mus81 processes recombination intermediates and its loss impairs repair of MMS-induced DSBs. Reason: Correct, corroborated by IMP evidence (PMID:17307401, PMID:17363897). Supporting Evidence: PMID:17307401 In Deltamus7 and Deltamus81 cells, the repair of MMS-induced DNA double-strand breaks (DSBs) is severely impaired.
GO:0003677 DNA binding	IEA GO_REF:0000002	KEEP AS NON CORE	Summary: InterPro2GO electronic annotation. Mus81 binds branched DNA substrates (it contains a winged-helix/HhH DNA-binding region in addition to the ERCC4 nuclease domain), so DNA binding is correct but generic; the specific structure-specific endonuclease activity is more informative. Reason: True but generic; subsumed by the more specific crossover junction DNA endonuclease activity. Supporting Evidence: PMID:14527419 a nicked HJ is the preferred substrate of endogenous and recombinant Mus81-Eme1
GO:0005634 nucleus	IEA GO_REF:0000044	ACCEPT	Summary: Electronic annotation from the UniProt Subcellular Location mapping. Mus81 is a nuclear protein, consistent with its role in chromosomal DNA repair and the experimental localization reported in the primary literature. Reason: Correct core localization, corroborated by experimental subcellular localization in S. pombe. Supporting Evidence: PMID:11719193 These findings constitute strong evidence that Mus81 and Eme1 are subunits of a nuclear Holliday junction resolvase.
GO:0006302 double-strand break repair	IEA GO_REF:0000002	ACCEPT	Summary: InterPro2GO electronic annotation for DSB repair. Supported by experimental S. pombe evidence (IMP); the more specific HR child term is also annotated. Reason: Correct, corroborated by IMP evidence (PMID:11719193, PMID:17307401). Supporting Evidence: PMID:17307401 In Deltamus7 and Deltamus81 cells, the repair of MMS-induced DNA double-strand breaks (DSBs) is severely impaired.
GO:0006308 DNA catabolic process	IEA GO_REF:0000002	REMOVE	Summary: InterPro2GO electronic annotation. Although Mus81 is a nuclease, "DNA catabolic process" is misleading for a structure-specific endonuclease whose biological role is resolving recombination/replication intermediates rather than bulk DNA degradation. The endonucleolytic incisions are part of DNA repair/recombination, not catabolism. Reason: Over-broad/misleading IEA; Mus81 makes precise resolving incisions in repair/recombination, not DNA degradation. The biology is captured by the recombination and repair BP terms. Supporting Evidence: PMID:14527419 Cleavage occurs specifically on the strand that opposes the nick, resulting in resolution of the structure into linear duplex products.
GO:0008821 crossover junction DNA endonuclease activity	IEA GO_REF:0000120	ACCEPT	Summary: Combined-IEA electronic annotation of the core endonuclease activity, duplicating the experimentally established function. Reason: Correct core MF, redundant with strong experimental evidence. Supporting Evidence: PMID:11719193 We report that Mus81 and an associated protein Eme1 are components of an endonuclease that resolves Holliday junctions into linear duplex products.
GO:0031297 replication fork processing	IEA GO_REF:0000117	ACCEPT	Summary: ARBA electronic annotation for replication fork processing, a well-supported core role in S. pombe (also annotated by IMP). Mus81-Eme1 cleaves stalled/collapsed forks and the branched intermediates that arise during fork repair and termination. Reason: Correct core process, corroborated by IMP evidence (PMID:28586299). Supporting Evidence: PMID:28586299 The heterodimeric structure-specific DNA endonuclease Mus81-Eme1 can cleave both stalled RFs and recombination intermediates, including D-loops and Holliday junctions
GO:0043596 nuclear replication fork	IEA GO_REF:0000117	KEEP AS NON CORE	Summary: ARBA electronic annotation placing Mus81 at the nuclear replication fork. This is consistent with its fork-processing role and is also supported by an IDA call (PMID:17363897 via ComplexPortal); Mus81-Eme1 acts on fork structures. A reasonable, if context-dependent, localization (it is recruited to forks/aberrant structures rather than constitutively fork-resident). Reason: Consistent with fork-associated activity but Mus81 is a damage/structure-recruited nuclease rather than a constitutive fork component; the core localization term is nucleus. Supporting Evidence: PMID:28586299 The heterodimeric structure-specific DNA endonuclease Mus81-Eme1 can cleave both stalled RFs and recombination intermediates, including D-loops and Holliday junctions
GO:0048476 Holliday junction resolvase complex	IEA GO_REF:0000117	ACCEPT	Summary: ARBA electronic annotation of complex membership, duplicating the experimentally established Mus81-Eme1 resolvase complex. Reason: Correct core CC, redundant with IDA/IPI evidence. Supporting Evidence: PMID:11719193 These findings constitute strong evidence that Mus81 and Eme1 are subunits of a nuclear Holliday junction resolvase.
GO:0007131 reciprocal meiotic recombination	IDA PMID:17363897 Mus81 cleavage of Holliday junctions: a failsafe for process...	ACCEPT	Summary: Direct (ComplexPortal) annotation that Mus81-Eme1 promotes meiotic crossovers (reciprocal recombination). The study purified active recombinant S. pombe Mus81-Eme1 with robust HJ cleavage and provided genetic evidence for its meiotic CO function; in fission yeast most or all crossovers depend on Mus81. Reason: Core meiotic process directly supported; fission yeast crossovers are essentially Mus81-dependent. Supporting Evidence: PMID:17363897 in the fission yeast Schizosaccharomyces pombe most, if not all, COs depend on Mus81
GO:0043596 nuclear replication fork	IDA PMID:17363897 Mus81 cleavage of Holliday junctions: a failsafe for process...	KEEP AS NON CORE	Summary: ComplexPortal IDA placing Mus81-Eme1 at the nuclear replication fork, reflecting its ability to bind and cleave fork structures. Mus81-Eme1 acts on replication-fork and fork-derived joint structures in mitotic cells. Reason: Reflects fork-associated activity; Mus81 is recruited to fork/branched structures rather than being a constitutive fork resident. Core localization is nucleus. Supporting Evidence: PMID:17363897 Mus81-Eme1 also functions in mitotic cells to promote the repair of DNA interstrand crosslinks and stalled and broken replication forks
GO:0048476 Holliday junction resolvase complex	IPI PMID:17363897 Mus81 cleavage of Holliday junctions: a failsafe for process...	ACCEPT	Summary: Physical-interaction (ComplexPortal IPI) evidence that Mus81 is part of the Mus81-Eme1 resolvase complex, the obligate heterodimer that cleaves Holliday junctions and other branched substrates. Reason: Core CC, supported by purification of the active Mus81-Eme1 heterodimer. Supporting Evidence: PMID:17363897 we report the purification of active forms of recombinant Schizosaccharomyces pombe Mus81-Eme1
GO:0032042 mitochondrial DNA metabolic process	IC GO_REF:0000111	MARK AS OVER ANNOTATED	Summary: Curator-inferred (IC) annotation combining the mitochondrial localization call (GO:0005739, HDA from PMID:16823372) with the endonuclease activity (GO:0008821) to infer a role in mitochondrial DNA metabolism. There is no direct functional evidence for a mitochondrial DNA role of Mus81 in S. pombe. The experimental HDA localization call cannot be adjudicated without the gene-specific image, but localization plus generic nuclease activity alone does not establish an mtDNA metabolic function. Reason: No direct Mus81 mtDNA phenotype, substrate assay, or other functional evidence supports the inferred mitochondrial DNA role. Supporting Evidence: PMID:11719193 These findings constitute strong evidence that Mus81 and Eme1 are subunits of a nuclear Holliday junction resolvase.
GO:0031297 replication fork processing	IMP PMID:28586299 Inter-Fork Strand Annealing causes genomic deletions during ...	ACCEPT	Summary: Mutant-phenotype evidence that Mus81 is required for processing of converging/collapsed replication forks. Loss of mus81 reduces spacer-dependent deletions arising during fork termination, and recombinant Mus81-Eme1 cleaves a model inter-fork-strand-annealing junction in vitro (catalytic-dead mutant cannot). Strong support for a core fork-processing role. Reason: Core process directly supported by mutant phenotype plus in vitro junction-cleavage assay. Supporting Evidence: PMID:28586299 loss of mus81 causes a > 2 fold reduction in SDDs in strains with either a 2 or 5 kb centromere-proximal spacer DNA (Figure 4B), indicating that Mus81-Eme1 specifically promotes SDDs.
GO:0007131 reciprocal meiotic recombination	IGI PMID:25414342 Rad51/Dmc1 paralogs and mediators oppose DNA helicases to li...	ACCEPT	Summary: Genetic-interaction evidence that Mus81-Eme1-dependent crossovers are promoted by Rad51/Dmc1 paralog/mediator complexes (e.g. Swi5-Sfr1) that antagonize the Fml1 and Rqh1 helicases. Reinforces the core meiotic crossover role of Mus81. Reason: Core meiotic process supported by genetic-interaction analysis. Supporting Evidence: PMID:25414342 play a major role in antagonizing both the FANCM-family DNA helicase/translocase Fml1 and the RecQ-type DNA helicase Rqh1 to limit hybrid DNA formation and promote Mus81-Eme1-dependent COs.
GO:0000724 double-strand break repair via homologous recombination	IMP PMID:17307401 The novel gene mus7(+) is involved in the repair of replicat...	ACCEPT	Summary: Mutant-phenotype evidence that Mus81 functions in repair of replication-associated DSBs. mus81 deletion (like mus7 deletion in the same pathway) severely impairs repair of MMS-induced DSBs, consistent with a role in HR-mediated repair of replication-associated breaks. Reason: Core repair process supported by mutant phenotype in S. pombe. Supporting Evidence: PMID:17307401 In Deltamus7 and Deltamus81 cells, the repair of MMS-induced DNA double-strand breaks (DSBs) is severely impaired.
GO:0006302 double-strand break repair	IMP PMID:11719193 Mus81-Eme1 are essential components of a Holliday junction r...	ACCEPT	Summary: Mutant-phenotype evidence (from the founding Mus81-Eme1 resolvase study) that Mus81 is required for DSB repair, specifically the resolution of recombination intermediates (Holliday junctions) arising during meiotic and damage-induced recombination. Reason: Core repair process; well supported by mutant analysis and the resolvase mechanism. Supporting Evidence: PMID:11719193 Mus81, a fission yeast protein related to the XPF subunit of ERCC1-XPF nucleotide excision repair endonuclease, is essential for meiosis and important for coping with stalled replication forks.
GO:0005515 protein binding	IPI PMID:11719193 Mus81-Eme1 are essential components of a Holliday junction r...	MARK AS OVER ANNOTATED	Summary: IPI annotation recording the physical interaction with Eme1 (SPAPB1E7.06c). The interaction is genuine and biologically central (Mus81 and Eme1 form the obligate heterodimeric endonuclease), but "protein binding" is uninformative. The relationship is better represented by the Holliday junction resolvase complex (GO:0048476) cellular component term, which is already annotated. Reason: The generic binding term adds no useful information beyond the already annotated Mus81-Eme1 Holliday junction resolvase complex and catalytic activity. Supporting Evidence: PMID:11719193 We report that Mus81 and an associated protein Eme1 are components of an endonuclease that resolves Holliday junctions into linear duplex products.
GO:0000712 resolution of meiotic recombination intermediates	IDA PMID:11719193 Mus81-Eme1 are essential components of a Holliday junction r...	ACCEPT	Summary: Direct-assay evidence that Mus81-Eme1 resolves Holliday junctions into linear duplex products, the biochemical activity underlying resolution of meiotic recombination intermediates. Core process. Reason: Core meiotic process directly demonstrated by the resolvase activity assay. Supporting Evidence: PMID:11719193 We report that Mus81 and an associated protein Eme1 are components of an endonuclease that resolves Holliday junctions into linear duplex products.
GO:0000712 resolution of meiotic recombination intermediates	IMP PMID:11719193 Mus81-Eme1 are essential components of a Holliday junction r...	ACCEPT	Summary: Mutant-phenotype support for the same core meiotic process: mus81 mutants are defective at a late step of meiotic recombination, and the meiotic defect is rescued by a bacterial Holliday junction resolvase, demonstrating that the missing function is junction resolution. Reason: Core meiotic process supported by the cross-complementation (bacterial resolvase rescue) experiment. Supporting Evidence: PMID:11719193 The mus81 meiotic defect is rescued by expression of a bacterial Holliday junction resolvase.
GO:0000712 resolution of meiotic recombination intermediates	IGI PMID:11719193 Mus81-Eme1 are essential components of a Holliday junction r...	ACCEPT	Summary: Genetic-interaction support (with eme1, SPAC17A5.11, and a further partner) for the same core meiotic resolution process. Mus81 and Eme1 act together in resolving meiotic recombination intermediates. Reason: Core meiotic process supported by genetic interaction with its obligate partner eme1. Supporting Evidence: PMID:11719193 Mus81 and Eme1 are required during meiosis at a late step of meiotic recombination.
GO:0008821 crossover junction DNA endonuclease activity	IDA PMID:11719193 Mus81-Eme1 are essential components of a Holliday junction r...	ACCEPT	Summary: Direct-assay evidence for the core molecular function: Mus81-Eme1 is an endonuclease that cleaves (crossover/Holliday) junction DNA into linear duplex products. Reason: Core molecular function directly demonstrated. Supporting Evidence: PMID:11719193 We report that Mus81 and an associated protein Eme1 are components of an endonuclease that resolves Holliday junctions into linear duplex products.
GO:0008821 crossover junction DNA endonuclease activity	IMP PMID:11719193 Mus81-Eme1 are essential components of a Holliday junction r...	ACCEPT	Summary: Mutant-phenotype support for the core endonuclease function. The catalytic DD->AA mutant (Asp395-Asp396) abrogates endonuclease activity, linking the activity to Mus81's ERCC4 catalytic residues. Reason: Core molecular function; the catalytic-site mutant confirms Mus81 contributes the nuclease activity. Supporting Evidence: PMID:11719193 Mus81, a fission yeast protein related to the XPF subunit of ERCC1-XPF nucleotide excision repair endonuclease, is essential for meiosis and important for coping with stalled replication forks.
GO:0048476 Holliday junction resolvase complex	IDA PMID:11719193 Mus81-Eme1 are essential components of a Holliday junction r...	ACCEPT	Summary: Direct evidence that Mus81 is a subunit of the nuclear Holliday junction resolvase complex (Mus81-Eme1). Core cellular component. Reason: Core CC directly demonstrated. Supporting Evidence: PMID:11719193 These findings constitute strong evidence that Mus81 and Eme1 are subunits of a nuclear Holliday junction resolvase.
GO:0031573 mitotic intra-S DNA damage checkpoint signaling	IMP PMID:19037101 Mus81, Rhp51(Rad51), and Rqh1 form an epistatic pathway requ...	ACCEPT	Summary: Mutant-phenotype evidence that Mus81 is required for checkpoint-dependent slowing of DNA replication in response to damage, acting downstream of Cds1 in an epistatic pathway with Rhp51 and Rqh1. Supports a role in the intra-S DNA damage checkpoint. Reason: Supported by mutant analysis placing Mus81 in the Cds1-dependent S-phase DNA damage checkpoint pathway. Supporting Evidence: PMID:19037101 defining an epistatic pathway in which mus81 is epistatic to rhp51 and rhp51 is epistatic to rqh1.
GO:0005634 nucleus	HDA PMID:16823372 ORFeome cloning and global analysis of protein localization ...	ACCEPT	Summary: High-throughput YFP localization (genome-wide ORFeome study) detecting Mus81 in the nucleus. Consistent with all functional data: Mus81 acts on chromosomal DNA in the nucleus. Reason: Correct core localization, concordant with experimental and curated nuclear localization. Supporting Evidence: PMID:11719193 These findings constitute strong evidence that Mus81 and Eme1 are subunits of a nuclear Holliday junction resolvase.
GO:0005739 mitochondrion	HDA PMID:16823372 ORFeome cloning and global analysis of protein localization ...	UNDECIDED	Summary: High-throughput YFP localization call placing Mus81 in the mitochondrion. The cached record for the genome-wide study is abstract-only and does not expose the gene-specific image or assay details needed to adjudicate this experimental call. Focused studies establish a nuclear role, and the distinct mitochondrial resolvase Ydc2 has direct mitochondrial-localization and mtDNA-maintenance evidence, but neither observation excludes a minor Mus81 mitochondrial pool. Reason: The supporting full text and raw gene-specific localization image were unavailable, so the experimental HDA call cannot be confidently accepted or rejected. Existing evidence establishes nuclear Mus81 biology but does not directly test whether Mus81 also has a mitochondrial pool. Supporting Evidence: PMID:11719193 These findings constitute strong evidence that Mus81 and Eme1 are subunits of a nuclear Holliday junction resolvase.
GO:0033314 mitotic DNA replication checkpoint signaling	IMP PMID:11073977 Damage tolerance protein Mus81 associates with the FHA1 doma...	KEEP AS NON CORE	Summary: The mus81-loss phenotype shows an intact checkpoint responding to lesions, rather than directly demonstrating that Mus81 transmits the checkpoint signal. The paper proposes that Mus81 recruits Cds1 to aberrant DNA structures, providing a plausible but not directly established signaling role. Reason: A context-specific checkpoint association is plausible from the Cds1 interaction and recruitment model, but the cited mutant phenotype does not establish Mus81 as a core checkpoint-signaling component. Supporting Evidence: PMID:11073977 We propose that Mus81 is involved in the recruitment of Cds1 to aberrant DNA structures where Cds1 modulates the activity of damage tolerance enzymes.
GO:0000709 meiotic joint molecule formation	TAS PMID:15466419 Swi5 acts in meiotic DNA joint molecule formation in Schizos...	MARK AS OVER ANNOTATED	Summary: Author-statement annotation derived from the Swi5 meiotic joint-molecule study, which describes Mus81-Eme1 as the activity that resolves joint molecules such as Holliday junctions. Note that Mus81 acts in the processing/resolution of joint molecules rather than in their formation per se; the cited evidence supports resolution. The term as annotated (joint molecule formation) is therefore a borderline fit. Reason: The cited evidence describes Mus81-Eme1 as resolving joint molecules, not forming them; resolution is already captured by GO:0000712. Supporting Evidence: PMID:15466419 the swi5 deletion strongly suppressed the low viable spore yield of mutants lacking Mus81*Eme1, which resolves joint molecules such as Holliday junctions.
GO:0006301 DNA damage tolerance	TAS PMID:14993467 The involvement of Srs2 in post-replication repair and homol...	KEEP AS NON CORE	Summary: Author-statement annotation: Mus81-Eme1 functions in a sub-pathway of post-replication repair for the tolerance/repair of UV-induced DNA damage, together with the Srs2 helicase. Consistent with Mus81's broader characterization as a damage-tolerance protein. Reason: Supported as a broad, context-dependent PRR/damage-tolerance role, but secondary to Mus81-Eme1's direct branched-DNA nuclease and repair functions. Supporting Evidence: PMID:14993467 Srs2 and the structure-specific endonuclease Mus81-Eme1 function in a sub-pathway of PRR for the tolerance/repair of UV-induced damage.
GO:0007131 reciprocal meiotic recombination	IMP PMID:14704204 Fission yeast Mus81.Eme1 Holliday junction resolvase is requ...	ACCEPT	Summary: Mutant-phenotype evidence that Mus81 is required for meiotic crossing over: mus81 mutants show normal/elevated gene conversion but 20-100-fold reduced crossover frequencies, genetically separating crossing over from gene conversion and establishing Mus81 as the meiotic crossover (reciprocal recombination) resolvase in S. pombe. Core meiotic function. Reason: Core meiotic crossover role directly demonstrated by mutant crossover/gene-conversion analysis. Supporting Evidence: PMID:14704204 Schizosaccharomyces pombe mus81 mutants have normal or elevated frequencies of gene conversion but 20- to 100-fold reduced frequencies of crossing over.
GO:0008821 crossover junction DNA endonuclease activity	IDA PMID:11741546 Human Mus81-associated endonuclease cleaves Holliday junctio...	ACCEPT	Summary: Direct biochemical evidence (from the human Mus81 ortholog) that Mus81-associated endonuclease cleaves Holliday junctions in vitro, resolving them into linear duplexes by cutting strands of like polarity. Supports the conserved crossover junction endonuclease activity assigned to fission yeast Mus81. Although the assay was on human Mus81, the activity is conserved and directly characterized for S. pombe Mus81-Eme1 in companion studies (PMID:11719193, PMID:14527419, PMID:17363897). Reason: Core molecular function; conserved HJ-cleavage activity directly demonstrated, with concordant S. pombe data. Supporting Evidence: PMID:11741546 Mus81-associated endonuclease resolves Holliday junctions into linear duplexes by cutting across the junction exclusively on strands of like polarity.
GO:0048476 Holliday junction resolvase complex	IDA PMID:14527419 The endogenous Mus81-Eme1 complex resolves Holliday junction...	ACCEPT	Summary: Direct evidence that the endogenous Mus81-Eme1 complex resolves Holliday junctions by a nick-and-counternick mechanism, confirming Mus81 as part of the resolvase complex and defining its mechanism (cleavage opposite the nick on a nicked HJ, its preferred substrate). Core cellular component and mechanism. Reason: Core CC directly demonstrated; the endogenous complex resolves HJs. Supporting Evidence: PMID:14527419 Mus81-Eme1 resolves HJs by a nick and counternick mechanism, with a large rate enhancement of the second cut arising from the flexible nature of the nicked HJ intermediate.
GO:0005634 nucleus	IBA GO_REF:0000033	ACCEPT	Summary: Phylogenetic IBA propagation of nuclear localization from the curated MUS81 family node. The node placement is concordant with direct S. pombe evidence identifying Mus81-Eme1 as a nuclear Holliday junction resolvase; target-derived experimental support in an IBA evidence set is expected and is not circular. Reason: Nuclear localization is directly established for S. pombe Mus81-Eme1, and there is no evidence of lineage-specific loss or divergence that would invalidate the PAINT node placement. Supporting Evidence: PMID:11719193 These findings constitute strong evidence that Mus81 and Eme1 are subunits of a nuclear Holliday junction resolvase.

Gene Description

Existing Annotations Review

Core Functions

Structure-specific (branched-DNA) endonuclease activity as the catalytic subunit of the Mus81-Eme1 complex, cleaving nicked Holliday junctions, 3'-flaps, D-loops, replication forks and intact Holliday junctions.

Resolution of meiotic recombination intermediates to generate reciprocal crossovers; in S. pombe Mus81-Eme1 is the principal/essential meiotic crossover resolvase, with most or all crossovers depending on it.

Processing of stalled and collapsed replication forks and repair of replication-associated DNA double-strand breaks via homologous recombination, cleaving fork-derived branched intermediates.

Effector of Cds1-dependent replication slowing during the mitotic intra-S DNA damage checkpoint, acting with Rhp51 and Rqh1 to process replication-stress intermediates.

References

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