Cyclic adenosine 3′, 5′-monophosphate (cAMP) and cyclic guanosine 3′, 5′- monophosphate (cGMP) are second messengers for numerous mammalian cell functions. The natural occurrence and synthesis of a third cyclic nucleotide (cNMP), cyclic cytidine 3′, 5′-monophosphate (cCMP), is a matter of controversy, and almost nothing is known about cyclic uridine 3′, 5′-monophosphate (cUMP). Bacillus anthracis and Bordetella ...
