3KF5

Structure of invertase from Schwanniomyces occidentalis

3KF5 の概要

• エントリーDOI: 10.2210/pdb3kf5/pdb
• 関連するPDBエントリー: 3KF3
• 分子名称: Invertase, 2-acetamido-2-deoxy-beta-D-glucopyranose, GLYCEROL, ... (4 entities in total)
• 機能のキーワード: invertase, gh32, glycoprotein, glycosidase, hydrolase
• 由来する生物種: Schwanniomyces occidentalis (Yeast)
• タンパク質・核酸の鎖数: 2
• 化学式量合計: 119353.68

構造登録者

Sanz-Aparicio, J.,Polo, A. (登録日: 2009-10-27, 公開日: 2010-02-23, 最終更新日: 2024-10-30)

主引用文献

Alvaro-Benito, M.,Polo, A.,Gonzalez, B.,Fernandez-Lobato, M.,Sanz-Aparicio, J.
Structural and kinetic analysis of Schwanniomyces occidentalis invertase reveals a new oligomerization pattern and the role of its supplementary domain in substrate binding
J.Biol.Chem., 285:13930-13941, 2010

PubMed Abstract: Schwanniomyces occidentalis invertase is an extracellular enzyme that hydrolyzes sucrose and releases beta-fructose from various oligosaccharides and essential storage fructan polymers such as inulin. We report here the three-dimensional structure of Sw. occidentalis invertase at 2.9 A resolution and its complex with fructose at 1.9 A resolution. The monomer presents a bimodular arrangement common to other GH32 enzymes, with an N-terminal 5-fold beta-propeller catalytic domain and a C-terminal beta-sandwich domain for which the function has been unknown until now. However, the dimeric nature of Sw. occidentalis invertase reveals a unique active site cleft shaped by both subunits that may be representative of other yeast enzymes reported to be multimeric. Binding of the tetrasaccharide nystose and the polymer inulin was explored by docking analysis, which suggested that medium size and long substrates are recognized by residues from both subunits. The identified residues were mutated, and the enzymatic activity of the mutants against sucrose, nystose, and inulin were investigated by kinetic analysis. The replacements that showed the largest effect on catalytic efficiency were Q228V, a residue putatively involved in nystose and inulin binding, and S281I, involved in a polar link at the dimer interface. Moreover, a significant decrease in catalytic efficiency against inulin was observed in the mutants Q435A and Y462A, both located in the beta-sandwich domain of the second monomer. This highlights the essential function that oligomerization plays in substrate specificity and assigns, for the first time, a direct catalytic role to the supplementary domain of a GH32 enzyme.

PubMed: 20181943
DOI: 10.1074/jbc.M109.095430

実験手法

X-RAY DIFFRACTION (2.9 Å)