Some aspects of EMS-induced mutagenesis in Escherichia coli.
AB2497 and its mutS and umuDC derivatives were EMS-treated at the stationary phase and specificity of mutation measured. It was found that: (i) in mutS+ cells EMS induces predominantly GC-->AT transitions (by supB or supE(oc) formation) and in mutS- cells mainly AT-->TA transversions (by supL(NG) formation); (ii) transversions of AT-->TA are umuDC-dependent and mutational specificity is biased towards AT-->GC transitions in mutS- umuDC- strains. When mutS- umuDC- cells were transfected with plasmids bearing umuD'C or umuDC genes, mutational specificity was again biased towards AT-->TA transversions; (iii) experiments with bacteria bearing umuC::lacZ or recA::lacZ fusions suggest that processing of UmuD-->UmuD' might be poorer in EMS-treated mutS- than in mutS+ cells.
Grzesiuk
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E
Institute of Biochemistry and Biophysics, Polish Academy of Sciences, Warsaw.
Janion
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C
D001426:Bacterial Proteins / Q000235:genetics; D004249:DNA Damage; D004260:DNA Repair; D004269:DNA, Bacterial / Q000187:drug effects; D004259:DNA-Directed DNA Polymerase; D004926:Escherichia coli / Q000187:drug effects* / Q000235:genetics; D029968:Escherichia coli Proteins; D005020:Ethyl Methanesulfonate / Q000633:toxicity*; D005798:Genes, Bacterial; D009152:Mutagenicity Tests; D009153:Mutagens / Q000633:toxicity*; D010957:Plasmids; D013014:SOS Response, Genetics
D001426:Bacterial Proteins; D004269:DNA, Bacterial; D029968:Escherichia coli Proteins; D009153:Mutagens; D005020:Ethyl Methanesulfonate; D004259:DNA-Directed DNA Polymerase; C055218:UmuD protein, E coli