Escherichia coli recA gene product inactivates phage lambda repressor.

Abstract
Phage .lambda. repressor is inactivated and cleaved into 2 detectable fragments during incubation with purified E. 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.