1-Deoxy-D-xylulose 5-phosphate
Overview
1-Deoxy-D-xylulose 5-phosphate (DXP) is an intermediate in the non-mevalonate pathway of isoprenoid precursor biosynthesis. This compound is a key player in the biosynthesis of isoprenoids, a diverse class of metabolites that includes essential molecules such as cholesterol, dolichol, coenzyme Q, and isopentenyl pyrophosphate.
Biosynthesis
DXP is synthesized from glyceraldehyde 3-phosphate and pyruvate by the enzyme DXP synthase. This reaction is the first committed step in the non-mevalonate pathway, also known as the 2-C-methyl-D-erythritol 4-phosphate/1-deoxy-D-xylulose 5-phosphate (MEP/DOXP) pathway.
Role in Isoprenoid Biosynthesis
Following its formation, DXP is converted into 2-C-methyl-D-erythritol 4-phosphate (MEP) by the enzyme DXP reductoisomerase. This is the second step in the non-mevalonate pathway. MEP is then used in the subsequent steps of the pathway to produce isopentenyl pyrophosphate and dimethylallyl pyrophosphate, the universal precursors to all isoprenoids.
Biological Significance
The non-mevalonate pathway, and thus DXP, is present in most bacteria, apicomplexan parasites, and plant plastids. It is absent in animals, fungi, and archaea, which instead use the mevalonate pathway to synthesize isoprenoids. This makes the enzymes of the non-mevalonate pathway, including DXP synthase and DXP reductoisomerase, potential targets for antibiotics and antimalarial drugs.