1MVY

Amylosucrase mutant E328Q co-crystallized with maltoheptaose.

1MVY の概要

• エントリーDOI: 10.2210/pdb1mvy/pdb
• 関連するPDBエントリー: 1G5A 1JG9 1JGI 1MW0 1MW1 1MW2 1MW3
• 関連するBIRD辞書のPRD_ID: PRD_900001 PRD_900010
• 分子名称: amylosucrase, alpha-D-glucopyranose-(1-4)-alpha-D-glucopyranose-(1-4)-alpha-D-glucopyranose-(1-4)-alpha-D-glucopyranose, alpha-D-glucopyranose-(1-4)-alpha-D-glucopyranose, ... (5 entities in total)
• 機能のキーワード: (beta-alpha)8 barrel, protein-sugar complex, transferase
• 由来する生物種: Neisseria polysaccharea
• タンパク質・核酸の鎖数: 1
• 化学式量合計: 72661.10

構造登録者

Skov, L.K.,Mirza, O.,Sprogoe, D.,Dar, I.,Remaud-Simeon, M.,Albenne, C.,Monsan, P.,Gajhede, M. (登録日: 2002-09-27, 公開日: 2002-12-18, 最終更新日: 2024-05-29)

主引用文献

Skov, L.K.,Mirza, O.,Sprogoe, D.,Dar, I.,Remaud-Simeon, M.,Albenne, C.,Monsan, P.,Gajhede, M.
Oligosaccharide and Sucrose Complexes of Amylosucrase. STRUCTURAL IMPLICATIONS FOR THE POLYMERASE ACTIVITY
J.BIOL.CHEM., 277:47741-47747, 2002

PubMed Abstract: The glucosyltransferase amylosucrase is structurally quite similar to the hydrolase alpha-amylase. How this switch in functionality is achieved is an important and fundamental question. The inactive E328Q amylosucrase variant has been co-crystallized with maltoheptaose, and the structure was determined by x-ray crystallography to 2.2 A resolution, revealing a maltoheptaose binding site in the B'-domain somewhat distant from the active site. Additional soaking of these crystals with maltoheptaose resulted in replacement of Tris in the active site with maltoheptaose, allowing the mapping of the -1 to +5 binding subsites. Crystals of amylosucrase were soaked with sucrose at different concentrations. The structures at approximately 2.1 A resolution revealed three new binding sites of different affinity. The highest affinity binding site is close to the active site but is not in the previously identified substrate access channel. Allosteric regulation seems necessary to facilitate access from this binding site. The structures show the pivotal role of the B'-domain in the transferase reaction. Based on these observations, an extension of the hydrolase reaction mechanism valid for this enzyme can be proposed. In this mechanism, the glycogen-like polymer is bound in the widest access channel to the active site. The polymer binding introduces structural changes that allow sucrose to migrate from its binding site into the active site and displace the polymer.

PubMed: 12364331
DOI: 10.1074/jbc.M207860200

実験手法

X-RAY DIFFRACTION (2 Å)