GLYCERALDEHYDE-3-PHOSPHATE AND PYRUVATE AS PRECURSORS OF ISOPRENIC UNITS IN AN ALTERNATIVE NON-MEVALONATE PATHWAY FOR TERPENOID BIOSYNTHESIS

Incorporation of C-13-labeled glycerol or pyruvate into the ubiquinone Q8 of Escherichia coli mutants lacking enzymes of the triose phosphat e metabolism and of (U-C-13(6))glucose into the triterpenoids of the h opane series of Zymomonas mobilis showed that glyceraldehyde 3-phospha te (or eventually glyceraldehyde) and a C-2 unit derived from pyruvate decarboxylation were the only precursors of the C-5 skeleton of isopr enic units in a novel non-mevalonate pathway for isoprenoid biosynthes is in these bacteria.