BIOSYNTHESIS OF ISOPRENOIDS IN ESCHERICHIA-COLI - THE FATE OF THE 3-HAND 4-H ATOMS OF 1-DEOXY-D-XYLULOSE

The ubiquinone obtained from E. coli after feeding of I-deoxy[3-H-2]xy lulose shows labeling of the E-methyl group in the terminal unit and o f all other positions derived from the terminal methylene group of iso pentenyl pyrophosphate, whilst label from I-deoxy[4-H-2]xylulose is re tained exclusively in the double bond corresponding to the dimethylall yl pyrophosphate starter unit.