Catalyzes the phosphorylation of pantothenate (Pan), the first step in CoA biosynthesis. (R)-pantothenate + ATP = (R)-4'-phosphopantothenate + ADP + H(+) Cofactor biosynthesis; coenzyme A biosynthesis; CoA from (R)-pantothenate: step 1/5. Homodimer. Belongs to the type II pantothenate kinase family.