title: Biochemical characterization of Bacillus subtilis type II isopentenyl diphosphate isomerase, and phylogenetic distribution of isoprenoid biosynthesis pathways.
abstract: An open reading frame (Acc. no. P50740) on the Bacillus subtilis chromosome extending from bp 184,997-186,043 with similarity to the idi-2 gene of Streptomyces sp. CL190 specifying type II isopentenyl diphosphate isomerase was expressed in a recombinant Escherichia coli strain. The recombinant protein with a subunit mass of 39 kDa was purified to apparent homogeneity by column chromatography. The protein was shown to catalyse the conversion of dimethylallyl diphosphate into isopentenyl diphosphate and vice versa at rates of 0.23 and 0.63 micromol.mg(-1).min(-1), respectively, as diagnosed by 1H spectroscopy. FMN and divalent cations are required for catalytic activity; the highest rates were found with Ca2+. NADPH is required under aerobic but not under anaerobic assay conditions. The enzyme is related to a widespread family of (S)-alpha-hydroxyacid oxidizing enzymes including flavocytochrome b2 and L-lactate dehydrogenase and was shown to catalyse the formation of [2,3-13C2]lactate from [2,3-13C2]pyruvate, albeit at a low rate of 1 nmol.mg(-1).min(-1). Putative genes specifying type II isopentenyl diphosphate isomerases were found in the genomes of Archaea and of certain eubacteria but not in the genomes of fungi, animals and plants. The analysis of the occurrence of idi-1 and idi-2 genes in conjunction with the mevalonate and nonmevalonate pathway in 283 completed and unfinished prokaryotic genomes revealed 10 different classes. Type II isomerase is essential in some important human pathogens including Staphylococcus aureus and Enterococcus faecalis where it may represent a novel target for anti-infective therapy.
authors.affiliation: Lehrstuhl für Organische Chemie und Biochemie, Technische Universität München, Garching, Germany.
authors.forename: Ralf
authors.initials: R
authors.lastname: Laupitz
authors.forename: Stefan
authors.initials: S
authors.lastname: Hecht
authors.forename: Sabine
authors.initials: S
authors.lastname: Amslinger
authors.forename: Ferdinand
authors.initials: F
authors.lastname: Zepeck
authors.forename: Johannes
authors.initials: J
authors.lastname: Kaiser
authors.forename: Gerald
authors.initials: G
authors.lastname: Richter
authors.forename: Nicholas
authors.initials: N
authors.lastname: Schramek
authors.forename: Stefan
authors.initials: S
authors.lastname: Steinbacher
authors.forename: Robert
authors.initials: R
authors.lastname: Huber
authors.forename: Duilio
authors.initials: D
authors.lastname: Arigoni
authors.forename: Adelbert
authors.initials: A
authors.lastname: Bacher
authors.forename: Wolfgang
authors.initials: W
authors.lastname: Eisenreich
authors.forename: Felix
authors.initials: F
authors.lastname: Rohdich
mesh_terms: D000595:Amino Acid Sequence; D001412:Bacillus subtilis / Q000201:enzymology*; D001483:Base Sequence; D002384:Catalysis; D017931:DNA Primers; D007535:Isomerases / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D008969:Molecular Sequence Data; D019906:Nuclear Magnetic Resonance, Biomolecular; D010802:Phylogeny; D017386:Sequence Homology, Amino Acid; D013729:Terpenes / Q000378:metabolism*; D014961:X-Ray Diffraction
chemical_list: D017931:DNA Primers; D013729:Terpenes; D007535:Isomerases