Geschmack ist vorhersagbar: Mit FlavorMiner. FlavorMiner heißt das Tool, das IPB-Chemiker und Partner aus Kolumbien jüngst entwickelt haben. Das Programm kann, basierend auf maschinellem Lernen (KI), anhand der…
Seit Februar 2021 bietet Wolfgang Brandt, ehemaliger Leiter der Arbeitsgruppe Computerchemie am IPB, sein Citizen Science-Projekt zur Pilzbestimmung an. Dafür hat er in regelmäßigen Abständen öffentliche Vorträge zur Vielfalt…
The coumarin antibiotic coumermycin A1 contains at least eight methyl groups, presumably derived from S-adenosylmethionine. Two putative methyltransferase genes, couO and couP, of the coumermycin A1 biosynthetic gene cluster were inactivated by in-frame deletion. In the resulting mutants, coumermycin A1 production was abolished. New coumermycin derivatives were accumulated instead, and were identified by HPLC-MS using selected reaction monitoring via electrospray ionization. couO mutants accumulated a coumermycin derivative lacking the methyl groups at C-8 of the characteristic aminocoumarin rings, whereas in the couP mutant a coumermycin derivative lacking the methyl groups at the 4-hydroxyl groups of the two deoxysugar moieties was identified. These results provided evidence that couO encodes a C-methyltransferase responsible for the transfer of a methyl group to C-8 of the aminocoumarin ring, and couP an O-methyltransferase for methylation of 4-OH of the sugar in the biosynthesis of coumermycin A1, respectively. C-methylation of the aminocoumarin ring is considered as an early step of coumermycin biosynthesis. Nevertheless, the intermediates with the non-methylated aminocoumarin ring were accepted by the enzymes catalysing the subsequent steps of the pathway. The new, demethylated secondary metabolites were produced in an amount at least as high as that of coumermycin A1 in the wild-type.
Publikation
Gao, W.; Loeser, R.; Raschke, M.; Dessoy, M. A.; Fulhorst, M.; Alpermann, H.; Wessjohann, L. A.; Zenk, M. H.;(E)-4-Hydroxy-3-methylbut-2-enyl Diphosphate: An Intermediate in the Formation of Terpenoids in Plant ChromoplastsAngew. Chem. Int. Ed.412604-2607(2002)DOI: 10.1002/1521-3773(20020715)41:14<2604::AID-ANIE2604>3.0.CO;2-S
The missing link in the new deoxyxylulose phosphate metabolic pathway leading to the biosynthesis of plant terpenoids has been identified. The intermediate between the cyclic diphosphate 1 and the basic isoprenoid building blocks dimethylallyl diphosphate and isopentenyl diphosphate has been shown for the first time to be (E )‐4‐hydroxy‐3‐methylbut‐2‐enyl diphosphate (2 ) by incorporation of tritium‐labeled 2 into phytoene.