Regulation and autoregulation by lexA protein.

The lexA protein represses many genes in E. coli. When the cell's DNA is damaged, lexA protein is inactivated and these genes are induced. Three aspects of lexA protein's repressor function are reviewed: how it regulates genes of the SOS response, how it regulates its own synthesis, and how it recognizes its operator sites. Recent studies of lexA protein's repressor function have suggested that the concentration of intact lexA protein after induction may determine the detailed control of the SOS response.