Previous Article | Next Article ![]()
J. Bacteriol., Feb 1996, 619-624, Vol 178, No. 3
FM Hahn, JA Baker and CD Poulter
Isopentenyl diphosphate (IPP) isomerase catalyzes an essential activation
step in the isoprenoid biosynthetic pathway. A database search based on
probes from the highly conserved regions in three eukaryotic IPP isomerases
revealed substantial similarity with ORF176 in the photosynthesis gene
cluster in Rhodobacter capsulatus. The open reading frame was cloned into
an Escherichia coli expression vector. The encoded 20-kDa protein, which
was purified in two steps by ion exchange and hydrophobic interaction
chromatography, catalyzed the interconversion of IPP and dimethylallyl
diphosphate. Thus, the photosynthesis gene cluster encodes all of the
enzymes required to incorporate IPP into the ultimate carotenoid and
bacteriochlorophyll metabolites in R. capsulatus. More recent searches
uncovered additional putative open reading frames for IPP isomerase in
seed-bearing plants (Oryza sativa, Arabadopsis thaliana, and Clarkia
breweri), a worm (Caenorhabiditis elegans), and another eubacterium
(Escherichia coli). The R. capsulatus enzyme is the smallest of the IPP
isomerases to be identified thus far and may consist mostly of a
fundamental catalytic core for the enzyme.
Copyright © 1996, American Society for Microbiology
Open reading frame 176 in the photosynthesis gene cluster of Rhodobacter capsulatus encodes idi, a gene for isopentenyl diphosphate isomerase
Department of Chemistry, University of Utah, Salt Lake City 84112, USA.
This article has been cited by other articles:
Copyright © 2009 by the American Society for Microbiology. For an alternate route to Journals.ASM.org, visit: http://intl-journals.asm.org | More Info»