Isolation and characterization of mutants of the plasmid pKM101 deficient in their ability to enhance mutagenesis and repair. [uv radiation, Salmonella typhimurium]

Journal Article · Wed Mar 01 04:00:00 EST 1978 · J. Bacteriol.; (United States)

OSTI ID:5043823

Walker, G C

A screening procedure was developed for identifying mutants of the plasmid pKM101 no longer capable of enhancing mutagenesis. The test was based on the large pKM101-mediated increase in the number of Gal/sup 4/ papillae observed on colonies of Salmonella typhimurium gal mutants plated on tetrazolium galactose plates in the presence of a mutagen. The pKM101 mutant plasmids transferred normally, were stably maintained in cells, caused normal levels of ampicillin resistance, and still imparted sensitivity to phage Ike to their hosts. However, the pKM101 mutants had lost the ability to enhance the reversion of both point and frameshift mutations, protect the cells against killing by uv irradiation, increase the spontaneous reversion rates of point mutations, enhance plasmid-mediated reactivation of uv-irradiated phage P22, enhance Weigle reactivation. One pKM101 mutant with different properties from the others was identified by its increased spontaneous mutator effect. It is suggested that pKM101 amplifies the activity of the inducible error-prone repair systems in bacteria and that this is the function of pKM101 in the Ames Salmonella tester strains used for detection of carcinogens as mutagens.

• Research Organization: Univ. of California, Berkeley
• OSTI ID: 5043823
• Journal Information: J. Bacteriol.; (United States), Journal Name: J. Bacteriol.; (United States) Vol. 133:3; ISSN JOBAA
• Country of Publication: United States
• Language: English

Related Subjects

560131* -- Radiation Effects on Microorganisms-- Basic Studies-- (-1987)
63 RADIATION, THERMAL, AND OTHER ENVIRON. POLLUTANT EFFECTS ON LIVING ORGS. AND BIOL. MAT.
BACTERIA
BIOLOGICAL EFFECTS
BIOLOGICAL RADIATION EFFECTS
BIOLOGICAL RECOVERY
BIOLOGICAL REPAIR
CELL CONSTITUENTS
ELECTROMAGNETIC RADIATION
MICROORGANISMS
MUTAGENESIS
MUTAGENS
MUTANTS
PLASMIDS
RADIATION EFFECTS
RADIATIONS
RECOVERY
REPAIR
SALMONELLA
SALMONELLA TYPHIMURIUM
ULTRAVIOLET RADIATION