酵母重组因子Rad51和Rad54介导的超螺旋驱动的同源DNA配对

Superhelicity-driven homologous DNA pairing by yeast recombination factors Rad51 and Rad54.

作者信息

Van Komen S, Petukhova G, Sigurdsson S, Stratton S, Sung P

机构信息

Department of Molecular Medicine and Institute of Biotechnology, University of Texas Health Science Center at San Antonio, 78245, USA.

出版信息

Mol Cell. 2000 Sep;6(3):563-72. doi: 10.1016/s1097-2765(00)00055-1.

DOI:10.1016/s1097-2765(00)00055-1

PMID:11030336

Abstract

Yeast Rad51 recombinase has only minimal ability to form D loop. Addition of Rad54 renders D loop formation by Rad51 efficient, even when topologically relaxed DNA is used as substrate. Treatment of the nucleoprotein complex of Rad54 and relaxed DNA with topoisomerases reveals dynamic DNA remodeling to generate unconstrained negative and positive supercoils. DNA remodeling requires ATP hydrolysis by Rad54 and is stimulated by Rad51-DNA nucleoprotein complex. A marked sensitivity of DNA undergoing remodeling to P1 nuclease indicates that the negative supercoils produced lead to transient DNA strand separation. Thus, a specific interaction of Rad54 with the Rad51-ssDNA complex enhances the ability of the former to remodel DNA and allows the latter to harvest the negative supercoils generated for DNA joint formation.

摘要

酵母Rad51重组酶形成D环的能力非常有限。即使使用拓扑松弛的DNA作为底物，添加Rad54也能使Rad51高效形成D环。用拓扑异构酶处理Rad54与松弛DNA的核蛋白复合物，可揭示动态的DNA重塑过程，以产生无约束的负超螺旋和正超螺旋。DNA重塑需要Rad54水解ATP，并受到Rad51-DNA核蛋白复合物的刺激。正在重塑的DNA对P1核酸酶具有显著的敏感性，这表明产生的负超螺旋会导致DNA链短暂分离。因此，Rad54与Rad51-ssDNA复合物的特异性相互作用增强了前者重塑DNA的能力，并使后者能够利用产生的负超螺旋进行DNA连接形成。