IUBMB Enzyme Nomenclature


Accepted name: phosphopantothenate—cysteine ligase (ATP)

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

For diagram of reaction click here.

Other name(s): phosphopantothenoylcysteine synthetase (ambiguous); PPCS (gene name)

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

Comments: A key enzyme in the production of coenzyme A. The eukaryotic enzyme requires ATP, in contrast to the bacterial enzyme, EC, phosphopantothenate—cysteine ligase, which requires CTP.

Links to other databases: BRENDA, EXPASY, KEGG, MetaCyc, CAS registry number:


1. Daugherty, M. Complete reconstitution of the human coenzyme A biosynthetic pathway via comparative genomics. J. Biol. Chem. 277 (2002) 21431-21439. [PMID: 11923312]

2. Manoj, N., Strauss, E., Begley, T.P. and Ealick, S.E. Structure of human phosphopantothenoylcysteine synthetase at 2.3 Å Resolution. Structure 11 (2003) 927-936. [PMID: 12906824]

3. Kupke, T., Hernandez-Acosta, P. and Culianez-Macia, F.A. 4'-phosphopantetheine and coenzyme A biosynthesis in plants. J. Biol. Chem. 278 (2003) 38229-38237. [PMID: 12860978]

[EC created 2017]

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