期刊名称：Proceedings of the National Academy of Sciences
印刷版ISSN：0027-8424
电子版ISSN：1091-6490
出版年度：2004
卷号：101
期号：26
页码：9562-9567
DOI：10.1073/pnas.0403416101
语种：English
出版社：The National Academy of Sciences of the United States of America
摘要：Repair of double-strand breaks is essential for the maintenance of genome integrity and cell survival. In eukaryotes, double-strand-break repair by homologous recombination requires the Rad52 group of proteins. Human Rad52 protein (HsRad52)-mediated annealing of complementary strands has been studied in detail, but little has been reported on the recombinase activities of HsRad52. For this study, we purified HsRad52 from Escherichia coli. DNase I protection experiments indicated that HsRad52 binds preferentially to single-stranded DNA and protects it against digestion by DNase I. HsRad52 catalyzed D-loop formation in superhelical DNA, as well as strand exchange among oligonucleotide substrates. The formation of a stoichiometric complex between HsRad52 and single-stranded DNA was found to be critical for strand exchange activity, and the coating of both the single- and double-stranded oligonucleotides inhibited the exchange reaction.
