DXP reductoisomerase

DXP reductoisomerase (1-deoxy--xylulose 5-phosphate reductoisomerase or DXR) is an enzyme that interconverts 1-deoxy-D-xylulose 5-phosphate (DXP) and 2-C-methyl-D-erythritol 4-phosphate (MEP).

It is classified under EC 1.1.1.267.

It is part of the nonmevalonate pathway (MEP pathway), and it is inhibited by fosmidomycin.

It is normally abbreviated DXR, but it is sometimes named IspC, as the product of the ispC gene.

This enzyme is responsible for terpenoid biosynthesis in some organisms. In Arabidopsis thaliana 1-deoxy-D-xylulose 5-phosphate reductoisomerase is the first committed enzyme of the non-mevalonate pathway for isoprenoid biosynthesis. The enzyme requires Mn²⁺, Co²⁺ or Mg²⁺ for activity, with Mn²⁺ being most effective.