Isoprenoid biosynthesis in bacteria: a novel pathway for the early steps leading to isopentenyl diphosphate.

摘要: Incorporation of 13C-labelled glucose, acetate, pyruvate or erythrose allowed the determination origin carbon atoms triterpenoids hopane series and/or ubiquinones from several bacteria (Zymomonas mobilis, Methylobacterium fujisawaense, Escherichia coli and Alicyclobacillus acidoterrestris) confirmed our earlier results obtained by incorporation acetate into hopanoids other led to identification a novel biosynthetic route for early steps isoprenoid biosynthesis. The C5 framework isoprenic units most probably (i) condensation C2 unit derived decarboxylation (e.g. thiamine-activated acetaldehyde) on C-2 carbonyl group triose phosphate derivative issued dihydroxyacetone not (ii) transposition step. Although this hypothetical pathway resembles that L-valine biosynthesis, amino acid its precursors could be excluded as intermediates in formation units.