Human MUS81-EME2 can cleave a variety of DNA structures including intact Holliday junction and nicked duplex.
Human MUS81-EME2 can cleave a variety of DNA structures including intact Holliday junction and nicked duplex.
复制标题
DOI：
10.1093/nar/gku237
复制
发表时间：
2014-05
影响因子：
14.9
通讯作者：
Seo YS
中科院分区：
文献类型：
--
作者：
Amangyeld T;Shin YK;Lee M;Kwon B;Seo YS
MUS 81与XPF-ERCC 1内切核酸酶复合物的催化XPF亚基具有高度同源性。只有当分别与芽殖酵母和裂殖酵母中的调节亚基Mms 4或Eme 1以及人类中的EME 1或EME 2复合时，它才具有催化活性。尽管Mus 81复合物参与了体内重组中间体的分解，但从大肠杆菌分离的重组酵母Mus 81-Mms 4和人MUS 81-EME 1在体外不能切割完整的霍利迪连接（HJ）。在这项研究中，我们表明，人重组MUS 81-EME 2分离的E。与MUS 81-EME 1相比，大肠杆菌相对有效地切割HJ。此外，MUS 81-EME 2催化有切口和有缺口的双链脱氧核糖核酸（DNA）的切割，产生双链断裂。缺口和缺口处5′磷酸末端的存在使得DNA对MUS 81-EME 2切割的敏感性显著低于其不存在时的敏感性，这提高了这种活性可能在将不易修复的受损DNA双链体引导到重组修复途径中发挥作用的可能性。用未修饰形式的MUS 81-EME 1和MUS 81-EME 2观察到的底物特异性的显著差异表明它们在DNA处理中起相关但不重叠的作用。
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.
登录
查看更多内容
影响因子：
14.9
作者：
Kang MJ;Lee CH;Kang YH;Cho IT;Nguyen TA;Seo YS
通讯作者：
Seo YS
影响因子：
16
作者：
Chen, XB;Melchionna, R;McGowan, CH
通讯作者：
McGowan, CH
影响因子：
64.8
作者：
Cox, MM;Goodman, MF;Marians, KJ
通讯作者：
Marians, KJ
影响因子：
64.5
作者：
Fekairi S;Scaglione S;Chahwan C;Taylor ER;Tissier A;Coulon S;Dong MQ;Ruse C;Yates JR 3rd;Russell P;Fuchs RP;McGowan CH;Gaillard PHL
通讯作者：
Gaillard PHL
影响因子：
16
作者：
Ciccia, Alberto;Ling, Chen;West, Stephen C.
通讯作者：
West, Stephen C.