6-Deoxyerythronolide B Synthase Thioesterase-Catalyzed Macrocyclization Is Highly Stereoselective
摘要:
Macrocyclic polyketide natural products are an indispensable source of therapeutic agents. The final stage of their biosynthesis, macrocyclization, Is catalyzed regio- and stereoselectively by a thioesterase. A panel of substrates were synthesized to test their specificity for macrocyclization by the erythromycin polyketide synthase TE (DEBS TE) in vitro. It was shown that DEBS TE is highly stereospecific, successfully macrocyclizing a 14-member ring substrate with an R configured O-nucleophile, and highly regioselective, generating exclusively the 14-member lactone over the 12-member lactone.
Polyketide synthase thioesterases catalyze rapid hydrolysis of peptidyl thioesters
摘要:
Polyketide synthase (PKS) thioesterases (TEs) catalyze the macrocyclization of linear acyl chains into macrolactones. Herein we show that peptide based substrates are processed by PKS TEs with greater catalytic efficiency than more native like acyl substrates. This result strengths the link between PKS and non-ribosomal peptide synthetase systems and provides a new tool for studying PKS TEs. (C) 2009 Elsevier Ltd. All rights reserved.
An Evolutionary Model Encompassing Substrate Specificity and Reactivity of Type I Polyketide Synthase Thioesterases
作者:Taylor P. A. Hari、Puneet Labana、Meaghan Boileau、Christopher N. Boddy
DOI:10.1002/cbic.201402475
日期:2014.12.15
propose an evolutionarymodel in which thioesterases from polyketide biosynthesis are by nature non‐selective for the type of chemistry they catalyze, producing a range of metabolites including acids, macrolactones, dimers, and macrodiolides. As one metabolite becomes essential for improving fitness in a particular environment, the thioesterase evolves to enrich for that corresponding reactivity.