TY - JOUR
T1 - Stuffed Methyltransferase Catalyzes the Penultimate Step of Pyochelin Biosynthesis
AU - Ronnebaum, Trey A.
AU - McFarlane, Jeffrey S.
AU - Prisinzano, Thomas E.
AU - Booker, Squire J.
AU - Lamb, Audrey L.
N1 - Publisher Copyright:
© 2018 American Chemical Society.
PY - 2019/2/12
Y1 - 2019/2/12
N2 - Nonribosomal peptide synthetases use tailoring domains to incorporate chemical diversity into the final natural product. A structurally unique set of tailoring domains are found to be stuffed within adenylation domains and have only recently begun to be characterized. PchF is the NRPS termination module in pyochelin biosynthesis and includes a stuffed methyltransferase domain responsible for S-adenosylmethionine (AdoMet)-dependent N-methylation. Recent studies of stuffed methyltransferase domains propose a model in which methylation occurs on amino acids after adenylation and thiolation rather than after condensation to the nascent peptide chain. Herein, we characterize the adenylation and stuffed methyltransferase didomain of PchF through the synthesis and use of substrate analogues, steady-state kinetics, and onium chalcogen effects. We provide evidence that methylation occurs through an SN2 reaction after thiolation, condensation, cyclization, and reduction of the module substrate cysteine and is the penultimate step in pyochelin biosynthesis.
AB - Nonribosomal peptide synthetases use tailoring domains to incorporate chemical diversity into the final natural product. A structurally unique set of tailoring domains are found to be stuffed within adenylation domains and have only recently begun to be characterized. PchF is the NRPS termination module in pyochelin biosynthesis and includes a stuffed methyltransferase domain responsible for S-adenosylmethionine (AdoMet)-dependent N-methylation. Recent studies of stuffed methyltransferase domains propose a model in which methylation occurs on amino acids after adenylation and thiolation rather than after condensation to the nascent peptide chain. Herein, we characterize the adenylation and stuffed methyltransferase didomain of PchF through the synthesis and use of substrate analogues, steady-state kinetics, and onium chalcogen effects. We provide evidence that methylation occurs through an SN2 reaction after thiolation, condensation, cyclization, and reduction of the module substrate cysteine and is the penultimate step in pyochelin biosynthesis.
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U2 - 10.1021/acs.biochem.8b00716
DO - 10.1021/acs.biochem.8b00716
M3 - Article
C2 - 30525512
AN - SCOPUS:85061398045
SN - 0006-2960
VL - 58
SP - 665
EP - 678
JO - Biochemistry
JF - Biochemistry
IS - 6
ER -