LexA

Normally RecA* binds LexA (a transcription repressor), activating LexA auto-protease activity,which destroys LexA repressor allowing production of DNA repair proteins. In lysogenic cells this response is hijacked, and RecA* stimulates cI autocleavage.

The SOS response in enteric bacteria is initiated by RecA protein, which becomes activated by DNA damage, and stimulates the autoproteolysis of several other proteins, including the LexA protein and the lambda cI repressor protein.

See also: Membrane, Vision, Gene, Organ, Protein