RuvAB and RecG are not essential for the recovery of DNA synthesis following UV-induced DNA damage in Escherichia coli.
Ultraviolet light induces DNA lesions that block the progression of the replication machinery. Several models speculate that the resumption of replication following disruption by UV-induced DNA damage requires regression of the nascent DNA or migration of the replication machinery away from the blocking lesion to allow repair or bypass of the lesion to occur. Both RuvAB and RecG catalyze branch migration of three- and four-stranded DNA junctions in vitro and are proposed to catalyze fork regression in vivo. To examine this possibility, we characterized the recovery of DNA synthesis in ruvAB and recG mutants. We found that in the absence of either RecG or RuvAB, arrested replication forks are maintained and DNA synthesis is resumed with kinetics that are similar to those in wild-type cells. The data presented here indicate that RecG- or RuvAB-catalyzed fork regression is not essential for DNA synthesis to resume following arrest by UV-induced DNA damage in vivo.
Donaldson
Janet R
JR
Department of Biological Sciences, Mississippi State University, Mississippi State, Mississippi 39762, USA. jrp12@msstate.edu
Courcelle
Charmain T
CT
Courcelle
Justin
J
D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism*; D004249:DNA Damage / Q000528:radiation effects*; D004265:DNA Helicases / Q000235:genetics / Q000378:metabolism*; D004261:DNA Replication / Q000235:genetics*; D004268:DNA-Binding Proteins / Q000235:genetics / Q000378:metabolism*; D004926:Escherichia coli; D029968:Escherichia coli Proteins / Q000235:genetics / Q000378:metabolism*; D008957:Models, Genetic; D013997:Time Factors; D014466:Ultraviolet Rays
D001426:Bacterial Proteins; D004268:DNA-Binding Proteins; D029968:Escherichia coli Proteins; C061260:RuvB protein, Bacteria; C071446:RecG protein, E coli; C071059:Holliday junction DNA helicase, E coli; D004265:DNA Helicases