Figure 2.

Proposed model for coordinate regulation of V. cholerae and V. parahaemolyticus virulence by inner-membrane proteins. In V. cholerae O1/O139 strains, TcpP, TcpH, ToxR and ToxS activate the transcription of toxT, whose gene product controls the expression of TCP and CT genes. In pathogenic V. parahaemolyticus strains, VtrA, VtrC, ToxR and ToxS control vtrB transcription. VtrB then activates the expression of T3SS genes. Known interactions between DNA-binding domains and promoters are indicated by solid arrows. A dashed arrow indicates that an interaction between ToxR and the vtrB promoter is pressumed but has not been experimentally confirmed. P: periplasm; IM: inner membrane, C: cytoplasm.