UmuD mutagenesis protein of Escherichia coli: Overproduction, purification, and cleavage by RecA
- Univ. of California, Berkeley (USA)
The mutation rate of Escherichia coli increases approximately 100-fold after treatment with replication-inhibiting agents such as UV light. This enhanced mutation rate requires the action of the UmuD and UmuC proteins, which are induced as part of the SOS response to DNA damage. To initiate a biochemical characterization of the role of these proteins, the authors have developed a plasmid system that gives efficient expression of the umuD and umuC genes. The umuD and umuC genes were placed under the control of a regulated phage {lambda} P{sub L} promoter and a synthetic ribosome-binding site, and the distance to the UmuD start was adjusted to maximize gene expression. Starting from this overproduction system, they have purified the UmuD protein and studied its interaction with RecA. The SOS response is turned on by the capacity of RecA protein to mediate cleavage of the LexA repressor for SOS-controlled operons. Others have shown that UmuD exhibits sequence homology to LexA around the cleavage site, suggesting a possible cleavage reaction for UmuD. They show that RecA mediates cleavage of UmuD, probably at this site. As with LexA, UmuD also undergoes a self-cleavage reaction. They infer that RecA-mediated cleavage of UmuD is another role for RecA in SOS mutagenesis, probably activating UmuD for its mutagenic function.
- OSTI ID:
- 6973733
- Journal Information:
- Proceedings of the National Academy of Sciences of the United States of America; (USA), Vol. 85:6, Issue 6; ISSN 0027-8424
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
59 BASIC BIOLOGICAL SCIENCES
DNA REPAIR
GENE REGULATION
ESCHERICHIA COLI
BIOLOGICAL RADIATION EFFECTS
PROTEINS
PURIFICATION
MOLECULAR BIOLOGY
MUTAGENESIS
PHOSPHORUS 32
PLASMIDS
SULFUR 35
ULTRAVIOLET RADIATION
BACTERIA
BETA DECAY RADIOISOTOPES
BETA-MINUS DECAY RADIOISOTOPES
BIOLOGICAL EFFECTS
BIOLOGICAL RECOVERY
BIOLOGICAL REPAIR
CELL CONSTITUENTS
DAYS LIVING RADIOISOTOPES
ELECTROMAGNETIC RADIATION
EVEN-ODD NUCLEI
ISOTOPES
LIGHT NUCLEI
MICROORGANISMS
NUCLEI
ODD-ODD NUCLEI
ORGANIC COMPOUNDS
PHOSPHORUS ISOTOPES
RADIATION EFFECTS
RADIATIONS
RADIOISOTOPES
RECOVERY
REPAIR
SULFUR ISOTOPES
560120* - Radiation Effects on Biochemicals
Cells
& Tissue Culture
550201 - Biochemistry- Tracer Techniques