Two functional domains in adenylate cyclase of Escherichia coli.

To study the regulation of Escherichia coli adenylate cyclase, plasmids that carry part of the cya gene, as well as plasmids containing hybrid genes having part of cya fused to part of lacZ, were constructed. This allowed us to propose that the enzyme is made of at least two well-defined domains. The NH2 terminus carries the ATP leads to cAMP catalytic activity, whereas the COOH-terminal end corresponds to a regulatory polypeptide domain.