Figure 2.

Comparison of domain structures of E. coli LexA protein and cI repressors of bacteriophage λ [19] and Shiga toxin-converting bacteriophage 933W [23, 24]. Two domains of these proteins are shown, and crucial amino acid residues are marked. Upon stimulation by the activated form of RecA (RecA^∗) both LexA and cI cleave their own molecules (at indicated positions) by the peptidase S24-like domains. The models were prepared using the DOG 1.0: Illustrator of Protein Domain Structures software [25].