Figure 1

Isoprenoid and amino acid biosynthetic pathways. A) Pathways for the biosynthesis of isoprenoid precursors. On the left, MVA pathway is represented. Enzymes are indicated in bold: AACT, acetoacetyl-CoA thiolase; HMGS, HMG-CoA synthase; HMGR, HMG-CoA reductase; MVK, mevalonate kinase; PMVK, 5-phosphomevalonate kinase; DPMD, 5-diphosphomevalonate decarboxylase; IDI, IPP/DMAPP isomerase. On the right, MEP pathway steps are described: GAP, D-glyceraldehyde 3-phosphate; DXP, 1-deoxy-D-xylulose 5-phosphate; MEP, 2-C-methyl-D-erythritol 4-phosphate; CDP-ME,4-diphosphocytidyl-2-C-methyl-D-erythritol; MEcPP, 2-C-methyl-D-erythritol 2,4-cyclodiphosphate; HMBPP, 4-hydroxy-3-methylbut-2-enyl diphosphate; IPP, isopentenyl diphosphate; DMAPP, dimethylallyl diphosphate. Enzymes are indicated in bold: DXS, DXP synthase; DXR, DXP reductoisomerase; MCT, MEP cytidylyltransferase; CMK, CDPME kinase; MDS, ME-cPP synthase; HDS, HMBPP synthase; HDR, HMBPP reductase; IDI, IPP isomerase. B) Amino acid biosynthesis. The common pathway (CP) is highlighted in black and enzymes indicated in bold: AK, aspartokinase; ASDH, aspartate semialdehyde dehydrogenase; HD, homoserine dehydrogenase. Solid arrows indicate single catalytic steps and dashed arrows mark multiple steps.