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 beta-alanine, followed by phosphorylation (EC
6.3.2.1 [pantoate---beta-alanine ligase] and EC
2.7.1.33 [pantothenate kinase], respectively). In archaea the order of these two steps is reversed, and phosphorylation precedes condensation with beta-alanine. The two archaeal enzymes that catalyse this conversion are EC
2.7.1.169, pantoate kinase, and this enzyme.