title: Hydroxyl regioisomerization of anthracycline catalyzed by a four-enzyme cascade.
abstract: Ranking among the most effective anticancer drugs, anthracyclines represent an important family of aromatic polyketides generated by type II polyketide synthases (PKSs). After formation of polyketide cores, the post-PKS tailoring modifications endow the scaffold with various structural diversities and biological activities. Here we demonstrate an unprecedented four-enzyme-participated hydroxyl regioisomerization process involved in the biosynthesis of kosinostatin. First, KstA15 and KstA16 function together to catalyze a cryptic hydroxylation of the 4-hydroxyl-anthraquinone core, yielding a 1,4-dihydroxyl product, which undergoes a chemically challenging asymmetric reduction-dearomatization subsequently acted by KstA11; then, KstA10 catalyzes a region-specific reduction concomitant with dehydration to afford the 1-hydroxyl anthraquinone. Remarkably, the shunt product identifications of both hydroxylation and reduction-dehydration reactions, the crystal structure of KstA11 with bound substrate and cofactor, and isotope incorporation experiments reveal mechanistic insights into the redox dearomatization and rearomatization steps. These findings provide a distinguished tailoring paradigm for type II PKS engineering.
authors.affiliation: State Key Laboratory of Bio-organic and Natural Products Chemistry, Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences, Shanghai 200032, China.
authors.forename: Zhuan
authors.initials: Z
authors.lastname: Zhang
authors.affiliation: State Key Laboratory of Bio-organic and Natural Products Chemistry, Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences, Shanghai 200032, China.
authors.forename: Yu-Kang
authors.initials: YK
authors.lastname: Gong
authors.affiliation: State Key Laboratory of Bio-organic and Natural Products Chemistry, Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences, Shanghai 200032, China.
authors.forename: Qiang
authors.initials: Q
authors.lastname: Zhou
authors.affiliation: State Key Laboratory of Bio-organic and Natural Products Chemistry, Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences, Shanghai 200032, China.
authors.forename: Yu
authors.initials: Y
authors.lastname: Hu
authors.affiliation: State Key Laboratory of Bio-organic and Natural Products Chemistry, Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences, Shanghai 200032, China.
authors.forename: Hong-Min
authors.initials: HM
authors.lastname: Ma
authors.affiliation: State Key Laboratory of Bio-organic and Natural Products Chemistry, Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences, Shanghai 200032, China.
authors.forename: Yong-Sheng
authors.initials: YS
authors.lastname: Chen
authors.affiliation: Biotechnology Research Center, Toyama Prefectural University, Toyama 939-0398, Japan.
authors.forename: Yasuhiro
authors.initials: Y
authors.lastname: Igarashi
authors.affiliation: State Key Laboratory of Bio-organic and Natural Products Chemistry, Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences, Shanghai 200032, China; gltang@sioc.ac.cn panlf@sioc.ac.cn.
authors.forename: Lifeng
authors.identifier: 0000-0002-9229-6288
authors.initials: L
authors.lastname: Pan
authors.affiliation: State Key Laboratory of Bio-organic and Natural Products Chemistry, Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences, Shanghai 200032, China; gltang@sioc.ac.cn panlf@sioc.ac.cn.
authors.forename: Gong-Li
authors.initials: GL
authors.lastname: Tang
mesh_terms: D000617:Aminoglycosides / Q000096:biosynthesis* / Q000737:chemistry; D018943:Anthracyclines / Q000737:chemistry / Q000378:metabolism*; D001426:Bacterial Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D055162:Biocatalysis; D053898:Biosynthetic Pathways; D004798:Enzymes / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D008847:Micromonospora / Q000235:genetics / Q000378:metabolism; D008958:Models, Molecular; D015394:Molecular Structure; D009154:Mutation; D000072417:Protein Domains; D013237:Stereoisomerism
chemical_list: D000617:Aminoglycosides; D018943:Anthracyclines; D001426:Bacterial Proteins; D004798:Enzymes; C455260:kosinostatin
keywords: C-4 deoxyanthracycline; NmrA-like short-chain dehydrogenase; biosynthesis; dehydroxylation; two-component hydroxylase