Adaptive response of Bacillus subtilis to N-Methyl-N'-Nitro-N-Nitrosoguanidine

Journal Article · Tue Feb 01 04:00:00 EST 1983 · J. Bacteriol.; (United States)

OSTI ID:6002557

Hadden, C T; Foote, R S; Mitra, S

Cell extracts of Bacillus subtilis contain a methyltransferase that appears to remove the O/sup 6/-methyl group from O/sup 6/-methylguanine in DNA in situ. This reaction proceeds in a stoichiometric fashion, as in Escherichia coli. However, the basal level of the enzyme (approximtely 240 molecules per cell) is significantly higher in B. subtilis than in E. coli. In addition, the methyltransferase level increases by an order of magnitude as a result of de novo protein synthesis after adaptive treatment with a low concentration of N-methyl-N'-nitro-N-nitrosoguanidine (MNNG), as in E. coli. Concomitant with adaption, B. subtilis cells become more resistant to both killing and mutagenesis by a challenge dose of N-methyl-N'-nitro-N-nitrosoguanidine. The authors present evidence to support the hypothesis that the majority of N-methyl-N'-nitro-N-nitrosoguanidine-induced mutations in B. subtilis are of the guanine-to-adenine transition type. 37 references, 6 figures, 1 table.

• Research Organization: Oak Ridge National Lab., TN
• DOE Contract Number: W-7405-ENG-26
• OSTI ID: 6002557
• Journal Information: J. Bacteriol.; (United States), Journal Name: J. Bacteriol.; (United States) Vol. 153:2; ISSN JOBAA
• 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.
BACILLUS
BACILLUS SUBTILIS
BACTERIA
BIOLOGICAL ADAPTATION
DNA
ENZYME ACTIVITY
ENZYMES
MICROORGANISMS
MUTAGENESIS
MUTATIONS
NITROSO COMPOUNDS
NUCLEIC ACIDS
ORGANIC COMPOUNDS
ORGANIC NITROGEN COMPOUNDS
PROTEINS
TOXICITY
TRANSFERASES