Escherichia coli recA gene product inactivates phage lambda repressor.

Phage lambda repressor is inactivated and cleaved into two detectable fragments during incubation with purified Escherichia coli recA gene protein in vitro, in a reaction that requires ATP. This reaction reproduces the recA-dependent inactivation of repressor that occurs in vivo during induction of the SOS functions. The proteolytic activity may reside in the recA protein itself and may be a fundamental activity of it.