The accessibility of Cys-120 in CheA(sub s) is important for the binding of CheZ and enhancement of CheZ phosphatase activity

The CheZ binding domain of CheA(sub s) is identified by testing the various fragments of CheA(sub s) that contain cysteine residues for CheZ binding activity in an ELISA-based CheA(sub s)-CheZ binding assay. It is shown that both the CheZ binding and activity enhancing functions of CheA(sub s) are located in its truncated P1 domain and the accessibility of the cysteine residue in P1 domain is important for the interaction between P1 domain and CheZ.