6SYU

The wild type glucuronoyl esterase OtCE15A from Opitutus terrae in complex with xylobiose

6SYU の概要

• エントリーDOI: 10.2210/pdb6syu/pdb
• 関連するBIRD辞書のPRD_ID: PRD_900116
• 分子名称: glucuronoyl esterase OtCE15A, beta-D-xylopyranose-(1-4)-beta-D-xylopyranose, MAGNESIUM ION, ... (6 entities in total)
• 機能のキーワード: esterase, complex, biomass, hydrolase
• 由来する生物種: Opitutus terrae
• タンパク質・核酸の鎖数: 1
• 化学式量合計: 47241.91

構造登録者

Mazurkewich, S.,Navarro Poulsen, J.C.,Larsbrink, J.,Lo Leggio, L. (登録日: 2019-10-01, 公開日: 2019-11-27, 最終更新日: 2024-01-24)

主引用文献

Mazurkewich, S.,Poulsen, J.N.,Lo Leggio, L.,Larsbrink, J.
Structural and biochemical studies of the glucuronoyl esteraseOtCE15A illuminate its interaction with lignocellulosic components.
J.Biol.Chem., 294:19978-19987, 2019

PubMed Abstract: Glucuronoyl esterases (GEs) catalyze the cleavage of ester linkages between lignin and glucuronic acid moieties on glucuronoxylan in plant biomass. As such, GEs represent promising biochemical tools in industrial processing of these recalcitrant resources. However, details on how GEs interact and catalyze degradation of their natural substrates are sparse, calling for thorough enzyme structure-function studies. Presented here is a structural and mechanistic investigation of the bacterial GE CE15A. GEs belong to the carbohydrate esterase family 15 (CE15), which is in turn part of the larger α/β-hydrolase superfamily. GEs contain a Ser-His-Asp/Glu catalytic triad, but the location of the catalytic acid in GEs has been shown to be variable, and CE15A possesses two putative catalytic acidic residues in the active site. Through site-directed mutagenesis, we demonstrate that these residues are functionally redundant, possibly indicating the evolutionary route toward new functionalities within the family. Structures determined with glucuronate, in both native and covalently bound intermediate states, and galacturonate provide insights into the catalytic mechanism of CE15. A structure of CE15A with the glucuronoxylooligosaccharide 2-(4--methyl-α-d-glucuronyl)-xylotriose (commonly referred to as XUX) shows that the enzyme can indeed interact with polysaccharides from the plant cell wall, and an additional structure with the disaccharide xylobiose revealed a surface binding site that could possibly indicate a recognition mechanism for long glucuronoxylan chains. Collectively, the results indicate that CE15A, and likely most of the CE15 family, can utilize esters of glucuronoxylooligosaccharides and support the proposal that these enzymes work on lignin-carbohydrate complexes in plant biomass.

PubMed: 31740581
DOI: 10.1074/jbc.RA119.011435

実験手法

X-RAY DIFFRACTION (1.33 Å)