Churchill, Jj Anderson, Dg Stephen Charles Kowalczykowski
Published in
Genes & Development
Double-strand DNA break repair and homologous recombination in Escherichia coli proceed by the RecBCD pathway, which is regulated by cis-acting elements known as chi sites. A crucial feature of this regulation is the RecBCD enzyme-directed loading of RecA protein specifically onto the 3 -terminal, chi-containing DNA strand. Here we show that RecBC ...
Harmon, Fg Stephen Charles Kowalczykowski
Published in
Genes & Development
RecQ helicase is important to homologous recombination and DNA repair in Escherichia coli. We demonstrate that RecQ helicase, in conjunction with RecA and SSB proteins, can initiate recombination events in vitro. In addition, RecQ protein is capable of unwinding a wide variety of DNA substrates, including joint molecules formed by RecA protein. The...
Nimonkar, Amitabh V Genschel, Jochen Kinoshita, Eri Polaczek, Piotr Campbell, Judith L Wyman, Claire Modrich, Paul Kowalczykowski, Stephen C
Published in
Genes & development
Repair of dsDNA breaks requires processing to produce 3'-terminated ssDNA. We biochemically reconstituted DNA end resection using purified human proteins: Bloom helicase (BLM); DNA2 helicase/nuclease; Exonuclease 1 (EXO1); the complex comprising MRE11, RAD50, and NBS1 (MRN); and Replication protein A (RPA). Resection occurs via two routes. In one, ...
Anderson, Dg Stephen Charles Kowalczykowski
Published in
Genes & Development
Homologous recombination in Escherichia coli is stimulated at DNA sequences known as chi sites. Stimulation requires the multifunctional RecBCD enzyme, which is both a helicase and a 3 —> 5 exonuclease. Upon recognition of a properly oriented chi site, the 3 —> 5 exonuclease activity is attenuated. Here we show that in addition to attenuation o...
Mazin, Av Stephen Charles Kowalczykowski
Published in
Genes & Development
RecA protein catalyzes DNA strand exchange, a basic step of homologous recombination. Upon binding to single-stranded DNA (ssDNA), RecA protein forms a helical nucleoprotein filament. Normally, this nucleoprotein filament binds double-stranded DNA (dsDNA) and promotes exchange of base pairs between this dsDNA and the homologous ssDNA that is contai...
Zaitsev, En Stephen Charles Kowalczykowski
Published in
Genes & Development
Traditionally, recombination reactions promoted by RecA-like proteins initiate by forming a nucleoprotein filament on a single-stranded DNA (ssDNA), which then pairs with homologous double-stranded DNA (dsDNA). In this paper, we describe a novel pairing process that occurs in an unconventional manner: RecA protein polymerizes along dsDNA to form an...
Tracy, Rb Stephen Charles Kowalczykowski
Published in
Genes & Development
The RecA protein and other DNA strand exchange proteins are characterized by their ability to bind and pair DNA in a sequence-independent manner. In vitro selection experiments demonstrate, unexpectedly, that RecA protein has a preferential affinity for DNA sequences rich in GT composition. Such GT-rich sequences are present in loci that display in...
Seitz, Em Brockman, Jp Sandler, Sj Clark, Aj Stephen Charles Kowalczykowski
Published in
Genes & Development
With the discovery that the Saccharomyces cerevisiae Rad51 protein is both structurally and functionally similar to the Escherichia coli RecA protein, the RecA paradigm for homologous recombination was extended to the Eucarya. The ubiquitous presence of RecA and Rad51 protein homologs raises the question of whether this archetypal protein exists wi...
Tracy, Rb Baumohl, Jk Stephen Charles Kowalczykowski
Published in
Genes & Development
The Rad51 protein of Saccharomyces cerevisiae is a eukaryotic homolog of the RecA protein, the prototypic DNA strand-exchange protein of Escherichia coli. RAD51 gene function is required for efficient genetic recombination and for DNA double-strand break repair. Recently, we demonstrated that RecA protein has a preferential affinity for GT-rich DNA...
