由RAD51-ssDNA核蛋白丝介导的DNA链交换，其极性与RecA相反。

DNA strand exchange mediated by a RAD51-ssDNA nucleoprotein filament with polarity opposite to that of RecA.

作者信息

Sung P, Robberson D L

机构信息

Sealy Center for Molecular Science, University of Texas Medical Branch at Galveston 77555-1061, USA.

出版信息

Cell. 1995 Aug 11;82(3):453-61. doi: 10.1016/0092-8674(95)90434-4.

DOI:10.1016/0092-8674(95)90434-4

PMID:7634335

Abstract

Yeast RAD51 gene functions in genetic recombination and DNA double-strand break repair. In vitro, in the presence of ATP and replication protein A, RAD51 protein pairs single-stranded DNA (ssDNA) with homologous double-stranded DNA (dsDNA) and catalyzes strand exchange between the synapsed DNA partners. Electron microscopic analyses show that RAD51 forms helical filaments on both ssDNA and dsDNA, in which the DNA is highly extended. However, results presented here indicate that only the RAD51-ssDNA nucleoprotein filament is functionally relevant. Strand exchange is arrested when heterology is encountered in the duplex partner, and analysis of the configuration of the terminal joint thus formed reveals that pairing and strand exchange initiate at the 5' end of the complementary strand in the linear duplex, a reaction polarity opposite to that of the bacterial prototype RecA.

摘要

酵母RAD51基因在遗传重组和DNA双链断裂修复中发挥作用。在体外，在ATP和复制蛋白A存在的情况下，RAD51蛋白使单链DNA（ssDNA）与同源双链DNA（dsDNA）配对，并催化突触结合的DNA伙伴之间的链交换。电子显微镜分析表明，RAD51在ssDNA和dsDNA上均形成螺旋丝，其中DNA高度伸展。然而，此处给出的结果表明，只有RAD51-ssDNA核蛋白丝具有功能相关性。当在双链体伙伴中遇到异源性时，链交换会停止，对由此形成的末端接头的构型分析表明，配对和链交换在线性双链体中互补链的5'端起始，这一反应极性与细菌原型RecA相反。