1deoxyDxylulose5phosphate

1-deoxy-D-xylulose-5-phosphate (DXP) is a phosphorylated five-carbon sugar phosphate that functions as a key intermediate in the non-mevalonate (MEP) pathway of isoprenoid biosynthesis in many bacteria, algae, and plants. The MEP pathway provides the universal precursors isopentenyl diphosphate (IPP) and dimethylallyl diphosphate (DMAPP), which are used for the synthesis of carotenoids, chlorophyll, quinones, and other essential isoprenoids. Humans rely on the mevalonate pathway for isoprenoid production and do not possess the MEP pathway, making the enzymes of this route attractive targets for antimicrobial and herbicidal strategies.

In organisms that contain it, DXP is synthesized from pyruvate and glyceraldehyde-3-phosphate by the enzyme 1-deoxy-D-xylulose-5-phosphate synthase (DXS). This reaction requires thiamine pyrophosphate (TPP) and divalent metal ions as cofactors. The resulting DXP is then converted to methylerythritol phosphate (MEP) by 1-deoxy-D-xylulose-5-phosphate reductoisomerase (DXR), a step that is a common target for antibiotics such as fosmidomycin. Subsequent steps, catalyzed by enzymes IspD, IspE, IspF, IspG, and IspH, modify and eventually reduce the molecule to IPP and DMAPP.

DXP’s role is foundational to the production of a broad class of essential biomolecules in many organisms. Research into the DXS and DXR enzymes continues to inform antibiotic development and agricultural chemistry, owing to the absence of the MEP pathway in humans and its conservation in many pathogens and plants.