Cloning and heterologous expression of a cDNA encoding 1-deoxy-D-xylulose-5-phosphate reductoisomerase of Arabidopsis thaliana

Various plant isoprenoids are synthesized via the non-mevalonate pathway of isopentenyl diphosphate formation. In this pathway, 1-deoxy-D-xylulose 5-p hosphate (DOXP), the first intermediate, is transformed to 2-C-methyl-D-ery thritol 4-phosphate (MEP) by an enzyme which was recently cloned from Esche richia coli, In order to find a plant homologue of this 1-deoxy-D-xylulose 5-phosphate reductoisomerase (DXR) Ive cloned a cDNA fragment from Arabidop sis thaliana which has high homology to the E. coli DXR. By expression of t his fragment in E. coli we could demonstrate that it encodes a protein whic h transforms DOXP to MEP. The antibiotic fosmidomycin specifically inhibits this DXR enzyme activity. (C) 1999 Federation of European Biochemical Soci eties.