Three variations of the MVA pathway discovered in the three domains of life - DPMD, MPD, and M3K routes. The enzymes with identically colored boxes indicate that they are evolutionarily related. Abbreviations for enzymes: AACT, acetoacetyl-CoA thiolase; HMGS, 3-hydroxy-3-methylglutaryl-CoA synthase; HMGR, 3-hydroxy-3-methylglutaryl-CoA reductase; MVK, mevalonate kinase; PMVK, phosphomevalonate kinase; DPMD, Diphosphomevalonate decarboxylase; IDI, IPP/DMAPP isomerase; MPD, mevalonate phosphate decarboxylase; IPK, isopentenyl phosphate kinase; M3K, mevalonate 3-kinase; M3PK, mevalonate 3-phosphate 5-kinase; MBD, mevalonate 3,5-bisphosphate decarboxylase.