title: Biosynthesis of isoprenoids: a bifunctional IspDF enzyme from Campylobacter jejuni.
abstract: In the nonmevalonate pathway of isoprenoid biosynthesis, the conversion of 2C-methyl-d-erythritol 4-phosphate into its cyclic diphosphate proceeds via nucleotidyl intermediates and is catalyzed by the products of the ispD, ispE and ispF genes. An open reading frame of Campylobacter jejuni with similarity to the ispD and ispF genes of Escherichia coli was cloned into an expression vector directing the formation of a 42 kDa protein in a recombinant E. coli strain. The purified protein was shown to catalyze the transformation of 2C-methyl-D-erythritol 4-phosphate into 4-diphosphocytidyl-2C-methyl-D-erythritol and the conversion of 4-diphosphocytidyl-2C-methyl-D-erythritol 2-phosphate into 2C-methyl-D-erythritol 2,4-cyclodiphosphate at catalytic rates of 19 micro mol x mg(-1) x min(-1) and 7 micro mol x mg(-1) x min(-1), respectively. Both enzyme-catalyzed reactions require divalent metal ions. The C. jejuni enzyme does not catalyze the formation of 2C-methyl-D-erythritol 3,4-cyclophosphate from 4-diphosphocytidyl-2C-methyl-D-erythritol, a side reaction catalyzed in vitro by the IspF proteins of E. coli and Plasmodium falciparum. Comparative genomic analysis show that all sequenced alpha- and epsilon-proteobacteria have fused ispDF genes. These bifunctional proteins are potential drug targets in several human pathogens (e.g. Helicobacter pylori, C. jejuni and Treponema pallidum).
authors.affiliation: Division of Biological Chemistry and Molecular Microbiology, School of Life Sciences, University of Dundee, UK.
authors.forename: Mads
authors.initials: M
authors.lastname: Gabrielsen
authors.forename: Felix
authors.initials: F
authors.lastname: Rohdich
authors.forename: Wolfgang
authors.initials: W
authors.lastname: Eisenreich
authors.forename: Tobias
authors.initials: T
authors.lastname: Gräwert
authors.forename: Stefan
authors.initials: S
authors.lastname: Hecht
authors.forename: Adelbert
authors.initials: A
authors.lastname: Bacher
authors.forename: William N
authors.initials: WN
authors.lastname: Hunter
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001426:Bacterial Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D016123:Campylobacter jejuni / Q000201:enzymology / Q000235:genetics / Q000378:metabolism*; D029968:Escherichia coli Proteins / Q000235:genetics / Q000378:metabolism; D006801:Humans; D008969:Molecular Sequence Data; D015394:Molecular Structure; D009097:Multienzyme Complexes / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D016366:Open Reading Frames; D019761:Phosphorus-Oxygen Lyases / Q000235:genetics / Q000378:metabolism; D010802:Phylogeny; D011994:Recombinant Proteins / Q000235:genetics / Q000378:metabolism; D016415:Sequence Alignment; D013403:Sugar Phosphates / Q000737:chemistry / Q000378:metabolism; D013729:Terpenes / Q000737:chemistry / Q000378:metabolism*
chemical_list: D001426:Bacterial Proteins; D029968:Escherichia coli Proteins; D009097:Multienzyme Complexes; D011994:Recombinant Proteins; D013403:Sugar Phosphates; D013729:Terpenes; D019761:Phosphorus-Oxygen Lyases; C400181:ISPF protein, E coli