Journal
JOURNAL OF MOLECULAR BIOLOGY
Volume 377, Issue 1, Pages 148-161Publisher
ACADEMIC PRESS LTD- ELSEVIER SCIENCE LTD
DOI: 10.1016/j.jmb.2007.12.025
Keywords
LexA; RecA; dimer; SOS; specific cleavage
Categories
Funding
- NIGMS NIH HHS [R01 GM065180, GM65180, R01 GM065180-03, R01 GM065180-02, R01 GM065180-04] Funding Source: Medline
Ask authors/readers for more resources
A critical step in the SOS response of Escherichia coli is the specific proteolytic cleavage of the LexA repressor. This reaction is catalyzed by an activated form of RecA, acting as a co-protease to stimulate the self-cleavage activity of LexA. This process has been reexamined in light of evidence that LexA is dimeric at physiological concentrations. We found that RecA-dependent cleavage was robust under conditions in which LexA is largely dimeric and conclude that LexA dimers are cleavable. We also found that LexA dimers dissociate slowly. Furthermore, our evidence suggests that interactions between the two subunits of a LexA dimer can influence the rate of cleavage. Finally, our evidence suggests that RecA stimulates the transition of LexA from its noncleavable to its cleavable conformation and therefore operates, at least in part, by an allosteric mechanism. (c) 2007 Elsevier Ltd. All rights reserved.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available