Appropriate initiation of the strand exchange reaction promoted by RecA protein requires ATP hydrolysis.
The DNA-dependent ATPase activity of the Escherichia coli RecA protein has been recognized for more than two decades. Yet, the role of ATP hydrolysis in the RecA-promoted strand exchange reaction remains unclear. Here, we demonstrate that ATP hydrolysis is required as part of a proofreading process during homology recognition. It enables the RecA-ssDNA complex, after determining that the strand-exchanged duplex is mismatched, to dissociate from the synaptic complex, which allows it to re-initiate the search for a "true" homologous region. Furthermore, the results suggest that when non-homologous sequences are present at the proximal end, ATP hydrolysis is required to allow ssDNA-RecA to reinitiate the strand exchange from an internal homologous region.
Zhang
Z
Z
Department of Chemistry & Biochemistry, University of Delaware, Newark 19716, USA.
Yoon
D
D
LaPorte
J R
JR
Chen
J
J
D000251:Adenosine Triphosphatases / Q000378:metabolism; D000255:Adenosine Triphosphate / Q000378:metabolism*; D020137:Base Pair Mismatch / Q000235:genetics; D020029:Base Pairing; D001483:Base Sequence; D004269:DNA, Bacterial / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D004277:DNA, Single-Stranded / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D004926:Escherichia coli / Q000201:enzymology* / Q000235:genetics*; D006868:Hydrolysis; D008969:Molecular Sequence Data; D011938:Rec A Recombinases / Q000378:metabolism*; D011995:Recombination, Genetic / Q000235:genetics*; D012689:Sequence Homology, Nucleic Acid
D004269:DNA, Bacterial; D004277:DNA, Single-Stranded; D000255:Adenosine Triphosphate; D011938:Rec A Recombinases; D000251:Adenosine Triphosphatases