title: Human MUS81-EME2 can cleave a variety of DNA structures including intact Holliday junction and nicked duplex.
abstract: MUS81 shares a high-degree homology with the catalytic XPF subunit of the XPF-ERCC1 endonuclease complex. It is catalytically active only when complexed with the regulatory subunits Mms4 or Eme1 in budding and fission yeasts, respectively, and EME1 or EME2 in humans. Although Mus81 complexes are implicated in the resolution of recombination intermediates in vivo, recombinant yeast Mus81-Mms4 and human MUS81-EME1 isolated from Escherichia coli fail to cleave intact Holliday junctions (HJs) in vitro. In this study, we show that human recombinant MUS81-EME2 isolated from E. coli cleaves HJs relatively efficiently, compared to MUS81-EME1. Furthermore, MUS81-EME2 catalyzed cleavage of nicked and gapped duplex deoxyribonucleic acids (DNAs), generating double-strand breaks. The presence of a 5' phosphate terminus at nicks and gaps rendered DNA significantly less susceptible to the cleavage by MUS81-EME2 than its absence, raising the possibility that this activity could play a role in channeling damaged DNA duplexes that are not readily repaired into the recombinational repair pathways. Significant differences in substrate specificity observed with unmodified forms of MUS81-EME1 and MUS81-EME2 suggest that they play related but non-overlapping roles in DNA transactions.
authors.affiliation: Department of Biological Sciences, Korea Advanced Institute of Science and Technology, Daejeon 305-701, Korea.
authors.forename: Tamir
authors.initials: T
authors.lastname: Amangyeld
authors.affiliation: Department of Biological Sciences, Korea Advanced Institute of Science and Technology, Daejeon 305-701, Korea.
authors.forename: Yong-Keol
authors.initials: YK
authors.lastname: Shin
authors.affiliation: Department of Biological Sciences, Korea Advanced Institute of Science and Technology, Daejeon 305-701, Korea.
authors.forename: Miju
authors.initials: M
authors.lastname: Lee
authors.affiliation: Department of Biological Sciences, Korea Advanced Institute of Science and Technology, Daejeon 305-701, Korea.
authors.forename: Buki
authors.initials: B
authors.lastname: Kwon
authors.affiliation: Department of Biological Sciences, Korea Advanced Institute of Science and Technology, Daejeon 305-701, Korea yeonsooseo@kaist.ac.kr.
authors.forename: Yeon-Soo
authors.initials: YS
authors.lastname: Seo
mesh_terms: D053903:DNA Breaks, Double-Stranded; D053904:DNA Breaks, Single-Stranded; D053837:DNA Cleavage; D045566:DNA, Cruciform / Q000737:chemistry*; D004268:DNA-Binding Proteins / Q000737:chemistry*; D004706:Endodeoxyribonucleases / Q000737:chemistry*; D004720:Endonucleases / Q000737:chemistry*; D004926:Escherichia coli; D006801:Humans; D007700:Kinetics; D046912:Multiprotein Complexes / Q000737:chemistry; D021122:Protein Subunits / Q000737:chemistry; D013379:Substrate Specificity
chemical_list: D045566:DNA, Cruciform; D004268:DNA-Binding Proteins; D046912:Multiprotein Complexes; D021122:Protein Subunits; C000588977:EME2 protein, human; C507947:Eme1 protein, human; D004706:Endodeoxyribonucleases; D004720:Endonucleases; C498772:MUS81 protein, human