Publications

• Isopentenyl diphosphate biosynthesis via a mevalonate-independent pathway: isopentenyl monophosphate kinase catalyzes the terminal enzymatic step.

  Lange B.M., Croteau R.

  In plants, the biosynthesis of isopentenyl diphosphate, the central precursor of all isoprenoids, proceeds via two separate pathways. The cytosolic compartment harbors the mevalonate pathway, whereas the newly discovered deoxyxylulose 5-phosphate pathway, which also operates in certain eubacteria, ... >> More

  In plants, the biosynthesis of isopentenyl diphosphate, the central precursor of all isoprenoids, proceeds via two separate pathways. The cytosolic compartment harbors the mevalonate pathway, whereas the newly discovered deoxyxylulose 5-phosphate pathway, which also operates in certain eubacteria, including Escherichia coli, is localized to plastids. Only the first two steps of the plastidial pathway, which involve the condensation of pyruvate and glyceraldehyde 3-phosphate to deoxyxylulose 5-phosphate followed by intramolecular rearrangement and reduction to 2-C-methylerythritol 4-phosphate, have been established. Here we report the cloning from peppermint (Mentha x piperita) and E. coli, and expression, of a kinase that catalyzes the phosphorylation of isopentenyl monophosphate as the last step of this biosynthetic sequence to isopentenyl diphosphate. The plant gene defines an ORF of 1,218 bp that, when the proposed plastidial targeting sequence is excluded, corresponds to approximately 308 aa with a mature size of approximately 33 kDa. The E. coli gene (ychB), which is located at 27.2 min of the chromosomal map, consists of 852 nt, encoding a deduced enzyme of 283 aa with a size of 31 kDa. These enzymes represent a conserved class of the GHMP family of kinases, which includes galactokinase, homoserine kinase, mevalonate kinase, and phosphomevalonate kinase, with homologues in plants and several eubacteria. Besides the preferred substrate isopentenyl monophosphate, the recombinant peppermint and E. coli kinases also phosphorylate isopentenol, and, much less efficiently, dimethylallyl alcohol, but dimethylallyl monophosphate does not serve as a substrate. Incubation of secretory cells isolated from peppermint glandular trichomes with isopentenyl monophosphate resulted in the rapid production of monoterpenes and sesquiterpenes, confirming that isopentenyl monophosphate is the physiologically relevant, terminal intermediate of the deoxyxylulose 5-phosphate pathway. << Less

  Proc. Natl. Acad. Sci. U.S.A. 96:13714-13719(1999) [PubMed] [EuropePMC]

• Methanocaldococcus jannaschii uses a modified mevalonate pathway for biosynthesis of isopentenyl diphosphate.

  Grochowski L.L., Xu H., White R.H.

  Archaea have been shown to produce isoprenoids from mevalonate; however, genome analysis has failed to identify several genes in the mevalonate pathway on the basis of sequence similarity. A predicted archaeal kinase, coded for by the MJ0044 gene, was associated with other mevalonate pathway genes ... >> More

  Archaea have been shown to produce isoprenoids from mevalonate; however, genome analysis has failed to identify several genes in the mevalonate pathway on the basis of sequence similarity. A predicted archaeal kinase, coded for by the MJ0044 gene, was associated with other mevalonate pathway genes in the archaea and was predicted to be the "missing" phosphomevalonate kinase. The MJ0044-derived protein was tested for phosphomevalonate kinase activity and was found not to catalyze this reaction. The MJ0044 gene product was found to phosphorylate isopentenyl phosphate, generating isopentenyl diphosphate. Unlike other known kinases associated with isoprene biosynthesis, Methanocaldococcus jannaschii isopentenyl phosphate kinase is predicted to be a member of the aspartokinase superfamily. << Less

  J. Bacteriol. 188:3192-3198(2006) [PubMed] [EuropePMC]

  This publication is cited by 1 other entry.