Figure 1.
The non-mevalonate MEP pathway of isoprenoid biosynthesis.
Isoprenoids are derived from the basic 5-carbon isoprenoid building blocks isopentenyl pyrophosphate (IPP) and its isomer, dimethylallyl pyrophosphate (DMAPP). In the MEP pathway, IPP and DMAPP are generated from pyruvate and glyceraldehyde 3-phosphate. Enzymes of this pathway are named here according to their E. coli homologs (DXR/IspC, IspD, IspE, and IspF). Fosmidomycin is a phosphonic acid antibiotic (PubChem compound ID 572) that inhibits a rate-limiting enzyme of this pathway (DXR/IspC) and blocks isoprenoid biosynthesis in vivo. Isoprenoids have great diversity in structure and cellular function—from plasma membrane stability (cholesterol), electron transport (ubiquinone), and cell wall biosynthesis (dolichols) to protein modification (as prenyl groups) and secondary metabolites (such as artemisinin).