Molecular signal for induction of the adaptive response to alkylating agents in E. coli

Conference · Thu May 01 04:00:00 EDT 1986 · Fed. Proc., Fed. Am. Soc. Exp. Biol.; (United States)

OSTI ID:5230227

Lindahl, T; Sedgwick, B; Teo, I; Kilpatrick, M; McCarthy, T; Hughes, S

Exposure of E. coli to simple alkylating agents such as methylnitrosourea causes the induction of at least three DNA repair functions, which are under the control of the ada gene. The intracellular signal for switching on the response has been identified as one of the two stereoisomers of methyl phosphotriesters generated in DNA by alkylation. The methyl group is transferred from the phosphotriester moiety to a specific cysteine residue within the regulatory Ada protein in a self-methylation reaction. This protein also corrects the mutagenic lesion O/sup 6/-methylguanine by transfer of its methyl group to a separate cysteine residue in the Ada protein. Methylation of the protein from repair of a DNA phosphotriester residue, but not from O/sup 6/-methylguanine, converts it to an activator of transcription of genes involved in the adaptive response. The activated form of the Ada protein enhances transcription by binding specifically to a sequence d(AAA--AAAGCGCA), located immediately upstream of the RNA polymerase binding site in relevant promoter regions.

• Research Organization: Clare Hall Labs., South Mimms, England
• OSTI ID: 5230227
• Report Number(s): CONF-8606151-
• Conference Information: Journal Name: Fed. Proc., Fed. Am. Soc. Exp. Biol.; (United States) Journal Volume: 45:6
• 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.
ALKYLATING AGENTS
ALKYLATION
AMINO ACIDS
BACTERIA
BIOLOGICAL ADAPTATION
BIOLOGICAL EFFECTS
BIOLOGICAL RECOVERY
BIOLOGICAL REPAIR
CARBOXYLIC ACIDS
CHEMICAL REACTIONS
CYSTEINE
DNA
DNA REPAIR
ESCHERICHIA COLI
GENES
GENETIC EFFECTS
MICROORGANISMS
NITROSO COMPOUNDS
NITROSOUREAS
NUCLEIC ACIDS
ORGANIC ACIDS
ORGANIC COMPOUNDS
ORGANIC NITROGEN COMPOUNDS
ORGANIC SULFUR COMPOUNDS
PROTEINS
RECOVERY
REPAIR
THIOLS
TRANSCRIPTION