Biosynthesis of terpenoids: YgbB protein converts 4-diphosphocytidyl-2C-methyl-D-erythritol 2-phosphate to 2C-methyl-D-erythritol 2,4-cyclodiphosphate.

摘要: In many microorganisms, the putative orthologs of Escherichia coli ygbB gene are tightly linked or fused to ygbP, which has been shown earlier be involved in terpenoid biosynthesis. The E. was expressed a recombinant strain and direct synthesis soluble, 17-kDa polypeptide. protein found convert 4-diphosphocytidyl-2C-methyl-D-erythritol 2-phosphate into 2C-methyl-D-erythritol 2,4-cyclodiphosphate CMP. structure reaction product established by NMR spectroscopy using (13)C-labeled substrate samples. enzyme-catalyzed requires Mn(2+) Mg(2+) but no other cofactors. Radioactivity from [2-(14)C]2C-methyl-D-erythritol diverted efficiently carotenoids isolated chromoplasts Capsicum annuum and, thus, as an intermediate deoxyxylulose phosphate pathway isoprenoid YgbB also 3,4-cyclophosphate. This compound does not serve for formation is assumed vitro without metabolic relevance.