DNA sequence analysis of mutagenicity and site specificity of ethyl methanesulfonate in Uvr+ and UvrB- strains of Escherichia coli

Journal Article · Fri Aug 01 04:00:00 EDT 1986 · Genetics; (United States)

OSTI ID:5002225

Burns, P A; Allen, F L; Glickman, B W

EMS-induced mutations within a 180 base pair region of the lacI gene of E. coli were cloned and sequenced. In total, 105 and 79 EMS-induced mutations from a Uvr+ and a UvrB- strain, respectively, were sequenced. The specificity of EMS-induced mutagenesis was very similar in the two strains; G:C----A:T transitions accounted for all but three of the mutants. The overall frequency of induced mutation was fivefold higher in the UvrB- strain compared to the Uvr+ strain. This demonstrates, at the DNA sequence level, that the presumed premutagenic lesion, O6-ethylguanine, is subject to repair by the uvrABC excision repair system of E. coli. An analysis of mutation frequencies with respect to neighboring base sequence, in the two strains, shows that O6-ethylguanine lesions adjacent to A:T base pairs present better targets for the excision repair machinery than those not adjacent to A:T base pairs.

• Research Organization: York Univ., Toronto, Ontario
• OSTI ID: 5002225
• Journal Information: Genetics; (United States), Journal Name: Genetics; (United States) Vol. 4; ISSN GENTA
• Country of Publication: United States
• Language: English

Related Subjects

560302* -- Chemicals Metabolism & Toxicology-- Microorganisms-- (-1987)
63 RADIATION, THERMAL, AND OTHER ENVIRON. POLLUTANT EFFECTS ON LIVING ORGS. AND BIOL. MAT.
BACTERIA
DNA SEQUENCING
EMS
ESCHERICHIA COLI
ESTERS
MICROORGANISMS
MUTAGENESIS
MUTAGENS
MUTATIONS
ORGANIC COMPOUNDS
ORGANIC SULFUR COMPOUNDS
STRUCTURAL CHEMICAL ANALYSIS
SULFONIC ACID ESTERS
TOXICITY