Open AccessCytochrome P450 Hydroxylase TnmL Catalyzing Sequential Hydroxylation with an Additional Proofreading Activity in Tiancimycin Biosynthesis
Author(s) -
Thibault Annaval,
Christia. Teijaro,
Ajeeth Adhikari,
Xiaohui Yan,
Jian-Jun Chen,
Ivana Crnovčić,
Dong Yang,
Ben Shen
Publication year - 2021
Publication title -
acs chemical biology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.899
H-Index - 111
eISSN - 1554-8937
pISSN - 1554-8929
DOI - 10.1021/acschembio.1c00365
Subject(s) - enediyne , biosynthesis , hydroxylation , stereochemistry , cytochrome p450 , biochemistry , chemistry , polyketide , natural product , enzyme , biology
Tiancimycin (TNM) A belongs to the anthraquinone-fused subfamily of enediyne natural products, and selected enediynes have been translated into clinical drugs. Previously, inactivation of tnmL in Streptomyces sp. CB03234 resulted in the accumulation of TNM B and TNM E, supporting the functional assignment of TnmL as a cytochrome P450 hydroxylase that catalyzes A-ring modification in TNM A biosynthesis. Herein, we report in vitro characterization of TnmL, revealing that (i) TnmL catalyzes two successive hydroxylations of TNM E, resulting in sequential production of TNM F and TNM C, (ii) TnmL shows a strict substrate preference, with the C-26 side chain playing a critical role in substrate binding, and (iii) TnmL demethylates the C-7 OCH 3 group of TNM G, affording TNM F, thereby channeling the shunt product TNM G back into TNM A biosynthesis and representing a rare proofreading logic for natural product biosynthesis. These findings shed new insights into anthraquinone-fused enediyne biosynthesis.