2OLG

Crystal structure of the serine protease domain of prophenoloxidase activating factor-I in a zymogen form

2OLG の概要

• エントリーDOI: 10.2210/pdb2olg/pdb
• 関連するPDBエントリー: 2B9L
• 分子名称: Pro-phenoloxidase activating enzyme-I, 2-acetamido-2-deoxy-beta-D-glucopyranose, SULFATE ION, ... (5 entities in total)
• 機能のキーワード: prophenoloxidase activating factor-i, ppaf-i, serine protease, hydrolase
• 由来する生物種: Holotrichia diomphalia
• タンパク質・核酸の鎖数: 1
• 化学式量合計: 30957.82

構造登録者

Ha, N.C.,Piao, S. (登録日: 2007-01-19, 公開日: 2007-02-06, 最終更新日: 2024-11-20)

主引用文献

Piao, S.,Kim, S.,Kim, J.H.,Park, J.W.,Lee, B.L.,Ha, N.C.
Crystal structure of the serine protease domain of prophenoloxidase activating factor-I
J.Biol.Chem., 282:10783-10791, 2007

PubMed Abstract: A family of serine proteases (SPs) mediates the proteolytic cascades of embryonic development and immune response in invertebrates. These proteases, called easter-type SPs, consist of clip and chymotrypsin-like SP domains. The SP domain of easter-type proteases differs from those of typical SPs in its primary structure. Herein, we report the first crystal structure of the SP domain of easter-type proteases, presented as that of prophenoloxidase activating factor (PPAF)-I in zymogen form. This structure reveals several important structural features including a bound calcium ion, an additional loop with a unique disulfide linkage, a canyon-like deep active site, and an exposed activation loop. We subsequently show the role of the bound calcium and the proteolytic susceptibility of the activation loop, which occurs in a clip domain-independent manner. Based on biochemical study in the presence of heparin, we suggest that PPAF-III, highly homologous to PPAF-I, contains a surface patch that is responsible for enhancing the catalytic activity through interaction with a nonsubstrate region of a target protein. These results provide insights into an activation mechanism of easter-type proteases in proteolytic cascades, in comparison with the well studied blood coagulation enzymes in mammals.

PubMed: 17287215
DOI: 10.1074/jbc.M611556200

実験手法

X-RAY DIFFRACTION (1.7 Å)