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 phosphorylation (EC 220.127.116.11 [pantoate—β-alanine ligase] and EC 18.104.22.168 [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 22.214.171.124, pantoate kinase, and this enzyme.
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. [DOI] [PMID: 19666462]