1JFH

STRUCTURE OF A PANCREATIC ALPHA-AMYLASE BOUND TO A SUBSTRATE ANALOGUE AT 2.03 ANGSTROM RESOLUTION

1JFH の概要

• エントリーDOI: 10.2210/pdb1jfh/pdb
• 関連するPDBエントリー: 1PPI
• 分子名称: ALPHA-AMYLASE, 4-S-methyl-4-thio-alpha-D-glucopyranose-(1-4)-methyl 4-thio-alpha-D-glucopyranoside, alpha-D-glucopyranose-(1-4)-1,4-dithio-alpha-D-glucopyranose, ... (7 entities in total)
• 機能のキーワード: hydrolase, o-glycosyl, alpha-amylase, methyl 4, 4'-dithio-alpha-maltotrioside
• 由来する生物種: Sus scrofa (pig)
• タンパク質・核酸の鎖数: 1
• 化学式量合計: 56860.22

構造登録者

Qian, M.,Payan, F. (登録日: 1997-09-19, 公開日: 1998-12-02, 最終更新日: 2024-10-23)

主引用文献

Qian, M.,Spinelli, S.,Driguez, H.,Payan, F.
Structure of a pancreatic alpha-amylase bound to a substrate analogue at 2.03 A resolution.
Protein Sci., 6:2285-2296, 1997

PubMed Abstract: The structure of pig pancreatic alpha-amylase in complex with carbohydrate inhibitor and proteinaceous inhibitors is known but the successive events occurring at the catalytic center still remain to be elucidated. The X-ray structure analysis of a crystal of pig pancreatic alpha-amylase (PPA, EC 3.2.1.1.) soaked with an enzyme-resistant substrate analogue, methyl 4,4'-dithio-alpha-maltotrioside, showed electron density corresponding to the binding of substrate analogue molecules at the active site and at the "second binding site." The electron density observed at the active site was interpreted in terms of overlapping networks of oligosaccharides, which show binding of substrate analogue molecules at subsites prior to and subsequent to the cleavage site. A weaker patch of density observed at subsite -1 (using a nomenclature where the site of hydrolysis is taken to be between subsites -1 and +1) was modeled with water molecules. Conformational changes take place upon substrate analogue binding and the "flexible loop" that constitutes the surface edge of the active site is observed in a specific conformation. This confirms that this loop plays an important role in the recognition and binding of the ligand. The crystal structure was refined at 2.03 A resolution, to an R-factor of 16.0 (Rfree, 18.5).

PubMed: 9385631

実験手法

X-RAY DIFFRACTION (2.03 Å)