IUBMB Enzyme Nomenclature


Accepted name: cytidylate cyclase

Reaction: CTP = 3',5'-cyclic CMP + diphosphate

Other name(s): 3',5'-cyclic-CMP synthase; cytidylyl cyclase; cytidyl cyclase; CTP diphosphate-lyase (cyclizing); pycC (gene name) (ambiguous)

Systematic name: CTP diphosphate-lyase (cyclizing; 3',5'-cyclic-CMP-forming)

Comments: In bacteria and archaea the enzyme's product, cCMP, functions as a second messenger in bacterial immunity against viruses. The enzyme is synthesized following phage infection and activates immune effectors that execute an antiviral response.

Links to other databases: BRENDA, EXPASY, KEGG, Metacyc, CAS registry number: 65357-82-6


1. Cech, S.Y. and Ignarro, L.J. Cytidine 3',5'-monophosphate (cyclic CMP) formation by homogenates of mouse liver. Biochem. Biophys. Res. Commun. 80 (1978) 119-125. [PMID: 23778]

2. Newton, R.P., Salih, S.G., Hakeem, N.A., Kingston, E.E. and Beynon, J.H. 3',5'-Cyclic UMP, -cyclic IMP, -cyclic TMP and related enzymes in mammalian-tissues. Biochem. Soc. Trans. 13 (1985) 1134-1135.

3. Tal, N., Morehouse, B.R., Millman, A., Stokar-Avihail, A., Avraham, C., Fedorenko, T., Yirmiya, E., Herbst, E., Brandis, A., Mehlman, T., Oppenheimer-Shaanan, Y., Keszei, A.FA., Shao, S., Amitai, G., Kranzusch, P.J. and Sorek, R. Cyclic CMP and cyclic UMP mediate bacterial immunity against phages. Cell 184 (2021) 5728–5739.e16. [PMID: 34644530]

[EC created 1989]

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