Isoprenoid biosynthesis in higher plants and in Escherichia coli: on the branching in the methylerythritol phosphate pathway and the independent biosynthesis of isopentenyl diphosphate and dimethylallyl diphosphate.
In the bacterium Escherichia coli, the mevalonic-acid (MVA)-independent 2-C-methyl-d-erythritol 4-phosphate (MEP) pathway is characterized by two branches leading separately to isopentenyl diphosphate (IPP) and dimethylallyl diphosphate (DMAPP). The signature of this branching is the retention of deuterium in DMAPP and the deuterium loss in IPP after incorporation of 1-[4-(2)H]deoxy-d-xylulose ([4-(2)H]DX). Feeding tobacco BY-2 cell-suspension cultures with [4-(2)H]DX resulted in deuterium retention in the isoprene units derived from DMAPP, as well as from IPP in the plastidial isoprenoids, phytoene and plastoquinone, synthesized via the MEP pathway. This labelling pattern represents direct evidence for the presence of the DMAPP branch of the MEP pathway in a higher plant, and shows that IPP can be synthesized from DMAPP in plant plastids, most probably via a plastidial IPP isomerase.
Hoeffler
Jean-François
JF
Université Louis Pasteur/CNRS, Institut Le Bel, 4 rue Blaise Pascal, 67070 Strasbourg cedex, France.
Hemmerlin
Andréa
A
Grosdemange-Billiard
Catherine
C
Bach
Thomas J
TJ
Rohmer
Michel
M
D002460:Cell Line; D004926:Escherichia coli / Q000378:metabolism*; D045782:Hemiterpenes; D007202:Indicators and Reagents; D009943:Organophosphorus Compounds / Q000138:chemical synthesis / Q000378:metabolism*; D010944:Plants / Q000378:metabolism*; D011106:Polyisoprenyl Phosphates / Q000096:biosynthesis* / Q000138:chemical synthesis; D014026:Nicotiana / Q000378:metabolism*; D014316:Tritium
D045782:Hemiterpenes; D007202:Indicators and Reagents; D009943:Organophosphorus Compounds; D011106:Polyisoprenyl Phosphates; D014316:Tritium; C004809:isopentenyl pyrophosphate; C043060:3,3-dimethylallyl pyrophosphate