Dem IPB wird erneut ein beispielhaftes Handeln im Sinne einer chancengleichheitsorientierten Personal- und Organisationspolitik bescheinigt. Das Institut erhält zum 6. Mal in Folge das TOTAL E-QUALITY…
Die Plant Science Student Conference (PSSC) wird seit 20 Jahren im jährlichen Wechsel von Studierenden der beiden Leibniz-Institute IPK und IPB organisiert. Im Interview erläutern Christina Wäsch…
Three geranylgeranyl pyrophosphate derivatives carrying an ether group at different positions within geranylgeranyl pyrophosphate were employed in biotransformations with five diterpene synthases (CotB2, PvHVS, PaFS, Bnd4 and TXS) derived from plants, bacteria and fungi. A total of six new oxygen-containing diterpenoids were isolated and characterized, deepening our knowledge on the substrate promiscuity of diterpene synthases. In addition, the diterpene synthase PvHVS also accepts an ether derivative of farnesyl pyrophosphate and converts it to the same tetrahydrofuran core as found for the analogous extended GGPP substrate. This result further demonstrates that diterpene synthases also exhibit promiscuity toward truncated unnatural substrates.
Publikation
Budde, J. L.; Çay, M.-Y.; Dräger, G.; Droste, J.; Hassanin, A.; Davari, M. D.; Kirschning, A.;Reprogramming the cyclization of the sesquiterpene synthase BcBOT2 using 2,3-Z-configured FPP derivatives and by means of “Methyl Mapping”ACS Catal.158125-8139(2025)DOI: 10.1021/acscatal.5c01224
The fungal sesquiterpene synthase BcBOT2 shows unique substrate promiscuity. It transforms farnesyl pyrophosphate (FPP) into presilphiperfolan-8β-ol via a cationic cascade that is initiated by a (1 → 11) cyclization. Here, it is shown that BcBOT2 also accepts (2,3-Z)-configured FPP derivatives, which provide terpenoids that result from an initial (1 → 6) cyclization. “Methyl mapping” was conducted by shifting the position of one or more methyl groups, and it was found that the location of methyl groups has a profound effect on the efficacy of cyclizations. In particular, the shift of the methyl group at C3 to the C2 position has the most profound effect on cyclohexane formation. Molecular modeling studies show that (1 → 6) cyclization took place due to adopting a different catalytically competent docking pose of FPP derivatives compared to natural FPP within the active site of the BcBOT2, which is mainly due to the (2,3-Z)-configuration. This docking pose leads to a C1−C6 distance shorter (3.3−3.5 Å) than the typical association with a near-attack conformation required for cyclization. Finally, these biotransformation results were benchmarked by a comprehensive study of the “hydrolysis” of eight different FPP derivatives. Under enzyme-free conditions, cyclohexene and cycloheptene terpenoids are formed. The ring size is mainly determined by the position of the methyl group at C6 or C7. The study reveals that in addition to protein engineering, unnatural substrates can also be used to specifically manipulate the mode of cyclization of terpene synthases.