Phosphorylates (R)-pantoate to form (R)-4-phosphopantoate in the CoA biosynthesis pathway (PubMed:19666462, PubMed:22865846). Displays broad nucleotide specificity and utilizes ATP, GTP, UTP, and CTP with comparable catalytic efficiencies (PubMed:22865846). (R)-pantoate + ATP = (R)-4-phosphopantoate + ADP + H(+) Moderately stimulated in the presence of potassium cations. Inhibited by increasing concentrations of pantoate. Activity is not affected by CoA/acetyl-CoA. Optimum pH is 7.5. Optimum temperature is 80 degrees Celsius. Cofactor biosynthesis; coenzyme A biosynthesis. Homodimer. Only viable in the presence of CoA or 4'-phosphopantothenate. Belongs to the GHMP kinase family. PoK subfamily.