7oq6

Publication Abstract from PubMed

WS9326A is a peptide antibiotic containing a highly unusual N-methyl-E-2-3-dehydrotyrosine (NMet-Dht) residue that is incorporated during peptide assembly on a non-ribosomal peptide synthetase (NRPS). The cytochrome P450 encoded by sas16 (P450(Sas)) has been shown to be essential for the formation of the alkene moiety in NMet-Dht, but the timing and mechanism of the P450(Sas)-mediated alpha,beta-dehydrogenation of Dht remained unclear. Here, we show that the substrate of P450(Sas) is the NRPS-associated peptidyl carrier protein (PCP)-bound dipeptide intermediate (Z)-2-pent-1'-enyl-cinnamoyl-Thr-N-Me-Tyr. We demonstrate that P450(Sas)-mediated incorporation of the double bond follows N-methylation of the Tyr by the N-methyl transferase domain found within the NRPS, and further that P450(Sas) appears to be specific for substrates containing the (Z)-2-pent-1'-enyl-cinnamoyl group. A crystal structure of P450(Sas) reveals differences between P450(Sas) and other P450s involved in the modification of NRPS-associated substrates, including the substitution of the canonical active site alcohol residue with a phenylalanine (F250), which in turn is critical to P450(Sas) activity and WS9326A biosynthesis. Together, our results suggest that P450(Sas) catalyses the direct dehydrogenation of the NRPS-bound dipeptide substrate, thus expanding the repertoire of P450 enzymes that can be used to produce biologically active peptides.

P450-mediated dehydrotyrosine formation during WS9326 biosynthesis proceeds via dehydrogenation of a specific acylated dipeptide substrate.,Zhang S, Zhang L, Greule A, Tailhades J, Marschall E, Prasongpholchai P, Leng DJ, Zhang J, Zhu J, Kaczmarski JA, Schittenhelm RB, Einsle O, Jackson CJ, Alberti F, Bechthold A, Zhang Y, Tosin M, Si T, Cryle MJ Acta Pharm Sin B. 2023 Aug;13(8):3561-3574. doi: 10.1016/j.apsb.2023.03.021. Epub , 2023 Mar 29. PMID:37655329^[1]

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.