IUBMB Enzyme Nomenclature


Accepted name: phosphopantothenate—cysteine ligase (CTP)

Reaction: CTP + (R)-4'-phosphopantothenate + L-cysteine = CMP + diphosphate + N-[(R)-4'-phosphopantothenoyl]-L-cysteine

For diagram of reaction click here.

Other name(s): phosphopantothenoylcysteine synthetase; phosphopantothenate—cysteine ligase

Systematic name: (R)-4'-phosphopantothenate:L-cysteine ligase

Comments: A key enzyme in the production of coenzyme A. The bacterial enzyme requires CTP, in contrast to the eukaryotic enzyme, EC, which requires ATP. Cysteine can be replaced by some of its derivatives.

Links to other databases: BRENDA, EXPASY, KEGG, MetaCyc, PDB, CAS registry number: 9023-50-1


1. Brown, G.M. The metabolism of pantothenic acid. J. Biol. Chem. 234 (1959) 370-378. [PMID: 13630913]

2. Strauss, E., Kinsland, C., Ge, Y., McLafferty, F.W. and Begley, T.P. Phosphopantothenoylcysteine synthetase from Escherichia coli. Identification and characterization of the last unidentified Coenzyme A biosynthetic enzymes in bacteria. J. Biol. Chem. 276 (2001) 13513-13516. [PMID: 11278255]

3. Kupke, T. Molecular characterization of the 4'-phosphopantothenoylcysteine synthetase domain of bacterial Dfp flavoproteins. J. Biol. Chem. 277 (2002) 36137-36145. [PMID: 12140293]

[EC created 1961, modified 2003, modified 2017]

Return to EC 6.3.2 home page
Return to EC 6.3 home page
Return to EC 6 home page
Return to Enzymes home page
Return to IUBMB Biochemical Nomenclature home page