1OBB

alpha-glucosidase A, AglA, from Thermotoga maritima in complex with maltose and NAD+

1OBB の概要

• エントリーDOI: 10.2210/pdb1obb/pdb
• 関連するBIRD辞書のPRD_ID: PRD_900001
• 分子名称: ALPHA-GLUCOSIDASE, alpha-D-glucopyranose-(1-4)-alpha-D-glucopyranose, NICOTINAMIDE-ADENINE-DINUCLEOTIDE, ... (4 entities in total)
• 機能のキーワード: glycosidase, sulfinic acid, nad+, maltose, hydrolase
• 由来する生物種: THERMOTOGA MARITIMA
• タンパク質・核酸の鎖数: 2
• 化学式量合計: 112319.60

構造登録者

Lodge, J.A.,Maier, T.,Liebl, W.,Hoffmann, V.,Strater, N. (登録日: 2003-01-29, 公開日: 2003-05-21, 最終更新日: 2024-10-16)

主引用文献

Lodge, J.A.,Maier, T.,Liebl, W.,Hoffmann, V.,Strater, N.
Crystal Structure of Thermotoga Maritima Alpha-Glucosidase Agla Defines a New Clan of Nad+-Dependent Glycosidases
J.Biol.Chem., 278:19151-, 2003

PubMed Abstract: Glycoside hydrolase family 4 represents an unusual group of glucosidases with a requirement for NAD+, divalent metal cations, and reducing conditions. The family is also unique in its inclusion of both alpha- and beta-specific enzymes. The alpha-glucosidase A, AglA, from Thermotoga maritima is a typical glycoside hydrolase family 4 enzyme, requiring NAD+ and Mn2+ as well as strongly reducing conditions for activity. Here we present the crystal structure of the protein complexed with NAD+ and maltose, refined at a resolution of 1.9 A. The NAD+ is bound to a typical Rossman fold NAD+-binding site, and the nicotinamide moiety is localized close to the maltose substrate. Within the active site the conserved Cys-174 and surrounding histidines are positioned to play a role in the hydrolysis reaction. The electron density maps indicate that Cys-174 is oxidized to a sulfinic acid. Most likely, the strongly reducing conditions are necessary to reduce the oxidized cysteine side chain. Notably, the canonical set of catalytic acidic residues common to other glucosidases is not present in the active site. This, combined with a high structural homology to NAD-dependent dehydrogenases, suggests an unusual and possibly unique mechanism of action for a glycoside-hydrolyzing enzyme.

PubMed: 12588867
DOI: 10.1074/JBC.M211626200

実験手法

X-RAY DIFFRACTION (1.9 Å)