title: Isoprenoid biosynthesis in bacteria: a novel pathway for the early steps leading to isopentenyl diphosphate.
abstract: Incorporation of 13C-labelled glucose, acetate, pyruvate or erythrose allowed the determination of the origin of the carbon atoms of triterpenoids of the hopane series and/or of the ubiquinones from several bacteria (Zymomonas mobilis, Methylobacterium fujisawaense, Escherichia coli and Alicyclobacillus acidoterrestris) confirmed our earlier results obtained by incorporation of 13C-labelled acetate into the hopanoids of other bacteria and led to the identification of a novel biosynthetic route for the early steps of isoprenoid biosynthesis. The C5 framework of isoprenic units results most probably (i) from the condensation of a C2 unit derived from pyruvate decarboxylation (e.g. thiamine-activated acetaldehyde) on the C-2 carbonyl group of a triose phosphate derivative issued probably from dihydroxyacetone phosphate and not from pyruvate and (ii) from a transposition step. Although this hypothetical biosynthetic pathway resembles that of L-valine biosynthesis, this amino acid or its C5 precursors could be excluded as intermediates in the formation of isoprenic units.
authors.affiliation: Ecole Nationale Supérieure de Chimie de Mulhouse, France.
authors.forename: M
authors.initials: M
authors.lastname: Rohmer
authors.forename: M
authors.initials: M
authors.lastname: Knani
authors.forename: P
authors.initials: P
authors.lastname: Simonin
authors.forename: B
authors.initials: B
authors.lastname: Sutter
authors.forename: H
authors.initials: H
authors.lastname: Sahm
mesh_terms: D001419:Bacteria / Q000378:metabolism*; D002247:Carbon Isotopes; D045782:Hemiterpenes; D009682:Magnetic Resonance Spectroscopy; D008798:Mevalonic Acid / Q000378:metabolism; D009943:Organophosphorus Compounds / Q000378:metabolism*; D011106:Polyisoprenyl Phosphates / Q000096:biosynthesis*; D013729:Terpenes / Q000378:metabolism
chemical_list: D002247:Carbon Isotopes; D045782:Hemiterpenes; D009943:Organophosphorus Compounds; D011106:Polyisoprenyl Phosphates; D013729:Terpenes; C004809:isopentenyl pyrophosphate; C043060:3,3-dimethylallyl pyrophosphate; D008798:Mevalonic Acid