3′,5′-Cyclic Adenosine Monophosphate-Requiring Mutants of Escherichia coli

Abstract

Mutants that require exogenous 3′,5′-cyclic adenosine monophosphate (cAMP) for exponential growth were isolated from strains deficient in adenyl cyclase. Studies of one strain showed that cAMP is not incorporated into macromolecules; instead, it seems to have a regulatory function, i.e., in media lacking cAMP, cells form ribonucleic acid (RNA) and protein at linear rather than exponential rates. The exact lesion is not known; ribosomes, messenger RNA, and the β and β′ subunits of RNA polymerase continue to be made in absence of added cAMP.