RecA-mediated cleavage activates UmuD for mutagenesis: Mechanistic relationship between transcriptional derepression and posttranslational activation

Journal Article · Mon Feb 29 23:00:00 EST 1988 · Proceedings of the National Academy of Sciences of the United States of America; (USA)

DOI:https://doi.org/10.1073/pnas.85.6.1816· OSTI ID:7099047

Nohmi, Takehiko; Battista, J R; Dodson, L A; Walker, G C ^[1]

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1. Massachusetts Institute of Technology, Cambridge (USA)

The products of the SOS-regulated umuDC operon are required for most UV and chemical mutagenesis in Escherichia coli. It has been shown that the UmuD protein shares homology with LexA, the repressor of the SOS genes. In this paper the authors describe a series of genetic experiments that indicate that the purpose of RecA-mediated cleavage of UmuD at its bond between Cys-24 and Gly-25 is to activate UmuD for its role in mutagenesis and that the COOH-terminal fragment of UmuD is necessary and sufficient for the role of UmuD in UV mutagenesis. Other genetic experiments are presented that (i) support the hypothesis that the primary role of Ser-60 in UmuD function is to act as a nucleophile in the RecA-mediated cleavage reaction and (ii) raise the possibility that RecA has a third role in UV mutagenesis besides mediating the cleavage of LexA and UmuD.

• OSTI ID: 7099047
• Journal Information: Proceedings of the National Academy of Sciences of the United States of America; (USA), Journal Name: Proceedings of the National Academy of Sciences of the United States of America; (USA) Vol. 85:6; ISSN 0027-8424; ISSN PNASA
• Country of Publication: United States
• Language: English

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59 BASIC BIOLOGICAL SCIENCES
63 RADIATION, THERMAL, AND OTHER ENVIRON. POLLUTANT EFFECTS ON LIVING ORGS. AND BIOL. MAT.
AMINO ACIDS
BACTERIA
BETA DECAY RADIOISOTOPES
BETA-MINUS DECAY RADIOISOTOPES
BIOLOGICAL EFFECTS
BIOLOGICAL RADIATION EFFECTS
BIOLOGICAL RECOVERY
BIOLOGICAL REPAIR
CARBOXYLIC ACIDS
CELL CONSTITUENTS
DAYS LIVING RADIOISOTOPES
DNA REPAIR
DOSE-RESPONSE RELATIONSHIPS
DRUGS
ELECTROMAGNETIC RADIATION
ESCHERICHIA COLI
EVEN-ODD NUCLEI
GENE OPERONS
ISOTOPES
LIGHT NUCLEI
LIPOTROPIC FACTORS
METHIONINE
MICROORGANISMS
MUTAGENESIS
NUCLEI
ORGANIC ACIDS
ORGANIC COMPOUNDS
ORGANIC SULFUR COMPOUNDS
PLASMIDS
POST-TRANSLATION MODIFICATION
PROTEINS
RADIATION EFFECTS
RADIATIONS
RADIOISOTOPES
RECOVERY
REPAIR
SULFUR 35
SULFUR ISOTOPES
TRANSCRIPTION
ULTRAVIOLET RADIATION