Essential monomer-monomer contacts define the minimal length for the N-terminus of RecA protein.
Published in Molecular Microbiology
Rad52 protein has a second stimulatory role in DNA strand exchange that complements replication protein-A function.
Published in Journal of Biological Chemistry
Rad52 protein plays a central role in double strand break repair and homologous recombination in Saccharomyces cerevisiae. We have identified a new mechanism by which Rad52 protein stimulates Rad51 protein-promoted DNA strand exchange. This function of Rad52 protein is revealed when subsaturating amounts (relative to the single-stranded DNA concent...
Processivity of the DNA helicase activity of Escherichia coli recBCD enzyme.
Published in Journal of Biological Chemistry
A fluorescence assay was used to measure the processivity of Escherichia coli recBCD enzyme helicase activity. Under standard conditions, recBCD enzyme unwinds an average of 30 +/- 3.2 kilobase pairs (kb)/DNA end before dissociating. The average processivity (P obs) of DNA unwinding under these conditions is 0.99997, indicating that the probability...
BRCA2 regulates DMC1-mediated recombination through the BRC repeats.
Published in Proceedings of the National Academy of Sciences
In somatic cells, BRCA2 is needed for RAD51-mediated homologous recombination. The meiosis-specific DNA strand exchange protein, DMC1, promotes the formation of DNA strand invasion products (joint molecules) between homologous molecules in a fashion similar to RAD51. BRCA2 interacts directly with both human RAD51 and DMC1; in the case of RAD51, thi...
Direct observation of individual RecA filaments assembling on single DNA molecules.
Published in Nature
Escherichia coli RecA is essential for the repair of DNA double-strand breaks by homologous recombination. Repair requires the formation of a RecA nucleoprotein filament. Previous studies have indicated a mechanism of filament assembly whereby slow nucleation of RecA protein on DNA is followed by rapid growth. However, many aspects of this process ...
Visualizing protein-DNA interactions at the single-molecule level.
Published in Current Opinion in Chemical Biology
Recent advancements in single-molecule methods have allowed researchers to directly observe proteins acting on their DNA targets in real-time. Single-molecule imaging of protein-DNA interactions permits detection of the dynamic behavior of individual complexes that otherwise would be obscured in ensemble experiments. The kinetics of these processes...
Facilitated loading of RecA protein is essential to recombination by RecBCD enzyme.
Published in Journal of Biological Chemistry
Although the RecB(2109)CD enzyme retains most of the biochemical functions associated with the wild-type RecBCD enzyme, it is completely defective for genetic recombination. Here, we demonstrate that the mutant enzyme exhibits an aberrant double-stranded DNA exonuclease activity, intrinsically producing a 3 -terminal single-stranded DNA overhang th...
Translocation of E. coli RecQ helicase on single-stranded DNA.
Published in Biochemistry
A member of the SF2 family of helicases, Escherichia coli RecQ, is involved in the recombination and repair of double-stranded DNA breaks and single-stranded DNA (ssDNA) gaps. Although the unwinding activity of this helicase has been studied biochemically, the mechanism of translocation remains unclear. To this end, using ssDNA of varying lengths, ...
DNA recombination and repair in the archaea.
Published in Advances in applied microbiology
Enhancement of Escherichia coli RecA protein enzymatic function by dATP.
Published in Biochemistry
The Escherichia coli recA protein has been shown to hydrolyze several nucleoside triphosphates in the presence of ssDNA. The substitution of dATP for rATP has significant effects on various recA protein biochemical properties. In the presence of dATP, recA protein can invade more secondary structure in native ssDNA than it can in the presence of rA...
