title: recA protein of Escherichia coli promotes branch migration, a kinetically distinct phase of DNA strand exchange.
abstract: The recA protein of Escherichia coli promotes the complete exchange of strands between full-length linear duplex and single-stranded circular DNA molecules of bacteriophage phi X-174, converting more than 50% of the single-stranded DNA into heteroduplex replicative form II-like structures. Kinetically, the reaction can be divided into two phases, formation of short heteroduplex regions (D loops) and extension of the D loops via branch migration. recA protein participates directly in both phases. D loops are formed efficiently in the presence of ATP or the nonhydrolyzable ATP analog adenosine 5'-[gamma-thio]triphosphate, whereas D-loop extension requires continuous ATP hydrolysis. Complete strand exchange requires a stoichiometric amount of recA protein and is strongly stimulated by the single-stranded-DNA-binding protein of E. coli.
mesh_terms: D001426:Bacterial Proteins / Q000502:physiology*; D002352:Carrier Proteins / Q000378:metabolism; D004247:DNA / Q000378:metabolism; D004269:DNA, Bacterial / Q000235:genetics; D004270:DNA, Circular / Q000235:genetics; D004277:DNA, Single-Stranded / Q000235:genetics; D004268:DNA-Binding Proteins; D004926:Escherichia coli / Q000235:genetics*; D007700:Kinetics; D011938:Rec A Recombinases; D011995:Recombination, Genetic
chemical_list: D001426:Bacterial Proteins; D002352:Carrier Proteins; D004269:DNA, Bacterial; D004270:DNA, Circular; D004277:DNA, Single-Stranded; D004268:DNA-Binding Proteins; D004247:DNA; D011938:Rec A Recombinases