IspG Converts an Epoxide Substrate Analogue to (<i>E</i>)-4-Hydroxy-3-methylbut-2-enyl Diphosphate: Implications for IspG Catalysis in Isoprenoid Biosynthesis
作者:Rodney L. Nyland II、Youli Xiao、Pinghua Liu、Caren L. Freel Meyers
DOI:10.1021/ja907470n
日期:2009.12.16
IspG is an intriguing enzyme in bacteria, parasite, and plant isoprenoid biosynthesis, and its catalytic mechanism remains elusive. We report here the synthesis of (2R,3R)-4-hydroxy-3-methyl-2,3-epoxybutanyl diphosphate (Epoxy-HMBPP), a proposed intermediate in one of the frequently cited mechanistic models. We have also demonstrated that this epoxide analogue is a catalytically competent IspG substrate. This study represents the first mechanistic study of this important enzyme.
Studies on the nonmevalonate pathway: formation of 2-C-methyl-d-erythritol 2,4-cyclodiphosphate from 2-phospho-4-(cytidine 5′-diphospho)-2-C-methyl-d-erythritol
2-Phospho-4-(cytidine 5'-diphospho)-2-C-methyl-D-erythritol was transformed to 2-C-methyl-D-erythritol 2,4-cyclodiphosphate by a novel Escherichia coli enzyme involved in the nonmevalonate pathway. (C) 2000 Elsevier Science Ltd. All rights reserved.