Phosphomevalonate kinase; part of the second module of ergosterol biosynthesis pathway that includes the middle steps of the pathway (PubMed:1846667). ERG8 converts 5-phosphomevalonate to 5-diphosphomevalonate (PubMed:1846667). The second module is carried out in the vacuole and involves the formation of farnesyl diphosphate, which is also an important intermediate in the biosynthesis of ubiquinone, dolichol, heme and prenylated proteins. Activity by the mevalonate kinase ERG12 first converts mevalonate into 5-phosphomevalonate. 5-phosphomevalonate is then further converted to 5-diphosphomevalonate by the phosphomevalonate kinase ERG8. The diphosphomevalonate decarboxylase MVD1/ERG19 then produces isopentenyl diphosphate. The isopentenyl-diphosphate delta-isomerase IDI1 then catalyzes the 1,3-allylic rearrangement of the homoallylic substrate isopentenyl (IPP) to its highly electrophilic allylic isomer, dimethylallyl diphosphate (DMAPP). Finally the farnesyl diphosphate synthase ERG20 catalyzes the sequential condensation of isopentenyl pyrophosphate with dimethylallyl pyrophosphate, and then with the resultant geranylpyrophosphate to the ultimate product farnesyl pyrophosphate (PubMed:32679672). (R)-5-phosphomevalonate + ATP = (R)-5-diphosphomevalonate + ADP Isoprenoid biosynthesis; isopentenyl diphosphate biosynthesis via mevalonate pathway; isopentenyl diphosphate from (R)-mevalonate: step 2/3. Present with 79 molecules/cell in log phase SD medium. Belongs to the GHMP kinase family. Mevalonate kinase subfamily.