FIG 5 .

Model for regulation of CrdA by both CrdS and CheA3. CrdS serves as the primary histidine kinase regulating the phosphorylation of CrdA. CheA3 can act as a phosphatase on CrdA~P to keep CrdA~P levels low. Activation of CrdA by phosphorylation allows CrdA to regulate developmental gene expression. The targets for CrdA are not yet known. CrdB is a predicated lipoprotein which contains a peptidoglycan-binding OmpA domain. Pbp1a is a putative penicillin binding protein. Both CrdB and Pbp1a are predicated to reside in the periplasm and possibly transmit envelop stress via Che3 and CrdS. Abbreviations are as follows; 3A, Mcp3A; 3B, Mcp3B; A3, CheA3; W3, CheW3; R3, CheR3; and B3, CheB3.