Crystal structure of the C67A mutant of isopentenyl diphosphate isomerase complexed with a mechanism-based irreversible inhibitor.
Isopentenyl diphosphate:dimethylallyl diphosphate (IPP:DMAPP) isomerase is a key enzyme in the biosynthesis of isoprenoids. The mechanism of the isomerization reaction involves protonation of the unactivated carbon-carbon double bond in the substrate. Analysis of the 1.97 A crystal structure of the inactive C67A mutant of E. coli isopentenyl diphosphate:dimethylallyl diphosphate isomerase complexed with the mechanism-based inactivator 3,4-epoxy-3-methyl-1-butyl diphosphate is in agreement with an isomerization mechanism involving Glu 116, Tyr 104, and Cys 67. In particular, the results are consistent with a mechanism where Glu116 is involved in the protonation step and Cys67 in the elimination step.
Wouters
J
J
Institut de Recherches Microbiologiques J.M. Wiame, Bruxelles, Belgium. jwouters@dbm.ulb.ac.be
Oudjama
Y
Y
Stalon
V
V
Droogmans
L
L
Poulter
C D
CD
D001665:Binding Sites; D019748:Carbon-Carbon Double Bond Isomerases / Q000037:antagonists & inhibitors* / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism; D018360:Crystallography, X-Ray; D004791:Enzyme Inhibitors / Q000737:chemistry* / Q000378:metabolism* / Q000494:pharmacology; D004852:Epoxy Compounds / Q000737:chemistry / Q000378:metabolism / Q000494:pharmacology; D004926:Escherichia coli / Q000201:enzymology* / Q000235:genetics; D045782:Hemiterpenes; D007536:Isomerism; D009943:Organophosphorus Compounds / Q000737:chemistry / Q000378:metabolism / Q000494:pharmacology; D017354:Point Mutation / Q000235:genetics*; D011522:Protons
D004791:Enzyme Inhibitors; D004852:Epoxy Compounds; D045782:Hemiterpenes; D009943:Organophosphorus Compounds; D011522:Protons; C077385:3-methyl-3,4-epoxybutyl diphosphate; D019748:Carbon-Carbon Double Bond Isomerases; C021453:isopentenyldiphosphate delta-isomerase