1nfs

Publication Abstract from PubMed

Isopentenyl diphosphate (IPP):dimethylallyl diphosphate (DMAPP) isomerase is a key enzyme in the biosynthesis of isoprenoids. The reaction involves protonation and deprotonation of the isoprenoid unit and proceeds through a carbocationic transition state. Analysis of the crystal structures (2 A) of complexes of Escherichia coli IPP.DMAPPs isomerase with a transition state analogue (N,N-dimethyl-2-amino-1-ethyl diphosphate) and a covalently attached irreversible inhibitor (3,4-epoxy-3-methyl-1-butyl diphosphate) indicates that Glu-116, Tyr-104, and Cys-67 are involved in the antarafacial addition/elimination of protons during isomerization. This work provides a new perspective about the mechanism of the reaction.

Catalytic mechanism of Escherichia coli isopentenyl diphosphate isomerase involves Cys-67, Glu-116, and Tyr-104 as suggested by crystal structures of complexes with transition state analogues and irreversible inhibitors.,Wouters J, Oudjama Y, Barkley SJ, Tricot C, Stalon V, Droogmans L, Poulter CD J Biol Chem. 2003 Apr 4;278(14):11903-8. Epub 2003 Jan 22. PMID:12540835^[3]

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.