IUBMB Enzyme Nomenclature


Accepted name: 4-phosphopantoate—β-alanine ligase

Reaction: ATP + (R)-4-phosphopantoate + β-alanine = AMP + diphosphate + (R)-4'-phosphopantothenate

Other name(s): phosphopantothenate synthetase; TK1686 protein

Systematic name: (R)-4-phosphopantoate:β-alanine ligase (AMP-forming)

Comments: The conversion of (R)-pantoate to (R)-4'-phosphopantothenate is part of the pathway leading to biosynthesis of 4'-phosphopantetheine, an essential cofactor of coenzyme A and acyl-carrier protein. In bacteria and eukaryotes this conversion is performed by condensation with β-alanine, followed by phosphrylation (EC [pantoate—β-alanine ligase] and EC [pantothenate kinase], respectively). In archaea the order of these two steps is reversed, and phosphorylation precedes condensation with β-alanine. The two archaeal enzymes that catalyse this conversion are EC, pantoate kinase, and this enzyme.

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


1. Yokooji, Y., Tomita, H., Atomi, H. and Imanaka, T. Pantoate kinase and phosphopantothenate synthetase, two novel enzymes necessary for CoA biosynthesis in the Archaea. J. Biol. Chem. 284 (2009) 28137-28145. [PMID: 19666462]

[EC created 2011]

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