Error-prone DNA polymerase IV is regulated by the heat shock chaperone GroE in Escherichia coli.
An insertion in the promoter of the operon that encodes the molecular chaperone GroE was isolated as an antimutator for stationary-phase or adaptive mutation. The groE operon consists of two genes, groES and groEL; point mutations in either gene conferred the same phenotype, reducing Lac+ adaptive mutation 10- to 20-fold. groE mutant strains had 1/10 the amount of error-prone DNA polymerase IV (Pol IV). In recG+ strains, the reduction in Pol IV was sufficient to account for their low rate of adaptive mutation, but in recG mutant strains, a deficiency of GroE had some additional effect on adaptive mutation. Pol IV is induced as part of the SOS response, but the effect of GroE on Pol IV was independent of LexA. We were unable to show that GroE interacts directly with Pol IV, suggesting that GroE may act indirectly. Together with previous results, these findings indicate that Pol IV is a component of several cellular stress responses.
Layton
Jill C
JC
Department of Biology, Indiana University, Jordan Hall, 1001 East Third St., Bloomington, IN 47405, USA.
Foster
Patricia L
PL
D000220:Adaptation, Biological; D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism / Q000502:physiology*; D018835:Chaperonin 10 / Q000235:genetics / Q000502:physiology; D018834:Chaperonin 60 / Q000235:genetics / Q000502:physiology; D018833:Chaperonins; D019951:DNA Polymerase beta / Q000378:metabolism*; D004926:Escherichia coli / Q000201:enzymology*; D029968:Escherichia coli Proteins / Q000235:genetics / Q000378:metabolism / Q000502:physiology; D015964:Gene Expression Regulation, Bacterial; D006360:Heat-Shock Proteins / Q000235:genetics / Q000378:metabolism / Q000502:physiology*; D016254:Mutagenesis, Insertional; D009154:Mutation / Q000235:genetics / Q000502:physiology; D017354:Point Mutation; D011401:Promoter Regions, Genetic; D013014:SOS Response, Genetics; D012697:Serine Endopeptidases / Q000502:physiology; D000099160:LexA Repressor Protein
D001426:Bacterial Proteins; D018835:Chaperonin 10; D018834:Chaperonin 60; D018833:Chaperonins; D019951:DNA Polymerase beta; D029968:Escherichia coli Proteins; D006360:Heat-Shock Proteins; D012697:Serine Endopeptidases; D000099160:LexA Repressor Protein; C028715:GroE protein, E coli