Open AccessBiosynthesis of terpenoids: YchB protein of Escherichia coli phosphorylates the 2-hydroxy group of 4-diphosphocytidyl-2C-methyl- d -erythritol
Author(s) -
Holger Lüttgen,
Felix Rohdich,
Stefan Herz,
Juraithip Wungsintaweekul,
Stefan Hecht,
Christoph A. Schuhr,
Monika Fellermeier,
Sylvia Sagner,
Meinhart H. Zenk,
Adelbert Bacher,
Wolfgang Eisenreich
Publication year - 2000
Publication title -
proceedings of the national academy of sciences of the united states of america
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 5.011
H-Index - 771
eISSN - 1091-6490
pISSN - 0027-8424
DOI - 10.1073/pnas.97.3.1062
Subject(s) - escherichia coli , biochemistry , biology , biosynthesis , terpenoid , chromoplast , gene , chloroplast , atp synthase , carotenoid , complementary dna , plastid
A comparative analysis of all published complete genomes indicated that the putative orthologs of the unannotatedychB gene ofEscherichia coli follow the distribution of thedxs ,dxr , andygbP genes, which have been shown to specify enzymes of the deoxyxylulose phosphate pathway of terpenoid biosynthesis, thus suggesting that the hypothetical YchB protein also is involved in that pathway. To test this hypothesis, theE. coli ychB gene was expressed in a homologous host. The recombinant protein was purified to homogeneity and was shown to phosphorylate 4-diphosphocytidyl-2C-methyl-d -erythritol in an ATP-dependent reaction. The reaction product was identified as 4-diphosphocytidyl-2C-methyl-d -erythritol 2-phosphate by NMR experiments with various13 C-labeled substrate samples. A14 C-labeled specimen of this compound was converted efficiently into carotenoids by isolated chromoplasts ofCapsicum annuum . The sequence ofE. coli YchB protein is similar to that of the protein predicted by the tomato cDNA pTOM41 (30% identity), which had been implicated in the conversion of chloroplasts to chromoplasts.