8H1M

Crystal structure of glucose-2-epimerase mutant_D254A from Runella slithyformis Runsl_4512

8H1M の概要

• エントリーDOI: 10.2210/pdb8h1m/pdb
• 分子名称: N-acylglucosamine 2-epimerase, FORMIC ACID (3 entities in total)
• 機能のキーワード: mutant form, isomerase, runsl
• 由来する生物種: Runella slithyformis
• タンパク質・核酸の鎖数: 1
• 化学式量合計: 48900.79

構造登録者

Wang, H.,Sun, X.M.,Saburi, W.,Yu, J.,Yao, M. (登録日: 2022-10-03, 公開日: 2023-07-12, 最終更新日: 2024-05-29)

主引用文献

Wang, H.,Sun, X.,Saburi, W.,Hashiguchi, S.,Yu, J.,Ose, T.,Mori, H.,Yao, M.
Structural insights into the substrate specificity and activity of a novel mannose 2-epimerase from Runella slithyformis.
Acta Crystallogr D Struct Biol, 79:585-595, 2023

PubMed Abstract: Mannose 2-epimerase (ME), a member of the acylglucosamine 2-epimerase (AGE) superfamily that catalyzes epimerization of D-mannose and D-glucose, has recently been characterized to have potential for D-mannose production. However, the substrate-recognition and catalytic mechanism of ME remains unknown. In this study, structures of Runella slithyformis ME (RsME) and its D254A mutant [RsME(D254A)] were determined in their apo forms and as intermediate-analog complexes [RsME-D-glucitol and RsME(D254A)-D-glucitol]. RsME possesses the (α/α)-barrel of the AGE superfamily members but has a unique pocket-covering long loop (loop). The RsME-D-glucitol structure showed that loop moves towards D-glucitol and closes the active pocket. Trp251 and Asp254 in loop are only conserved in MEs and interact with D-glucitol. Kinetic analyses of the mutants confirmed the importance of these residues for RsME activity. Moreover, the structures of RsME(D254A) and RsME(D254A)-D-glucitol revealed that Asp254 is vital for binding the ligand in a correct conformation and for active-pocket closure. Docking calculations and structural comparison with other 2-epimerases show that the longer loop in RsME causes steric hindrance upon binding to disaccharides. A detailed substrate-recognition and catalytic mechanism for monosaccharide-specific epimerization in RsME has been proposed.

PubMed: 37314406
DOI: 10.1107/S205979832300390X

実験手法

X-RAY DIFFRACTION (1.6 Å)