5THQ

Comprehensive Analysis of a Novel Ketoreductase for Pentangular Polyphenol Biosynthesis

5THQ の概要

• エントリーDOI: 10.2210/pdb5thq/pdb
• 関連するPDBエントリー: 5TII
• 分子名称: 3-oxoacyl-ACP reductase, NADPH DIHYDRO-NICOTINAMIDE-ADENINE-DINUCLEOTIDE PHOSPHATE (3 entities in total)
• 機能のキーワード: arixanthomycin, pentangular polyphenol polyketide, ketoreduction, oxidoreductase
• 由来する生物種: uncultured bacterium
• タンパク質・核酸の鎖数: 8
• 化学式量合計: 238443.14

構造登録者

Valentic, T.R.,Tsai, S.C.,Brady, S.F. (登録日: 2016-09-30, 公開日: 2016-11-09, 最終更新日: 2024-04-03)

主引用文献

Valentic, T.R.,Jackson, D.R.,Brady, S.F.,Tsai, S.C.
Comprehensive Analysis of a Novel Ketoreductase for Pentangular Polyphenol Biosynthesis.
ACS Chem. Biol., 11:3421-3430, 2016

PubMed Abstract: Arixanthomycins are pentangular polyphenols (PP) with potent antiproliferative activities that were discovered through the heterologous expression of environmental DNA-derived gene clusters. The biosynthesis of arixanthomycin and other PPs is unusual because it requires several novel type II polyketide synthase (PKS) enzymes for its complete maturation. Most type II PKSs contain a ketoreductase (KR) that mediates the C7-C12 first ring cyclization and C-9 reduction. In contrast, based on previous studies of product analysis and genome mining, the arixanthomycin (ARX) gene cluster harbors a C-11 reducing KR (ARX 27), a C9-C14 first-ring aromatase/cyclase (ARX 19), and an unprecedented C-17 and C-19 reducing KR (ARX 21). While bioinformatics is useful for predicting novel enzymes, the functions of ARX 19, ARX 21, and ARX 27 have yet to be confirmed. Further, the structural features that predispose the ARX biosynthetic enzymes to process atypical poly-β-ketone scaffolds remain unknown. We report the crystal structure of ARX 21, the first structure of an enzyme involved in PP biosynthesis and likely a C-17 and C-19 reducing-KR, which is structurally similar to C-15 reducing KRs. Structural comparison of ARX 21 and other C-9 reducing KRs revealed a difference in the enzyme active site that may enlighten the molecular basis of KR substrate specificity. In addition, we report the successful in vitro reconstitution of ARX 19. The structural characterization of ARX 21 in conjunction with the in vitro results of ARX 19 lays the groundwork toward a complete in vitro and structural characterization of type II PKS enzymes involved in PP biogenesis.

PubMed: 27779377
DOI: 10.1021/acschembio.6b00658

実験手法

X-RAY DIFFRACTION (2.3 Å)