1PJU

Unbound form of Tomato Inhibitor-II

1PJU の概要

• エントリーDOI: 10.2210/pdb1pju/pdb
• 関連するPDBエントリー: 1OYV
• 分子名称: Wound-induced proteinase inhibitor II, SULFATE ION (3 entities in total)
• 機能のキーワード: proteinase inhibitor, hydrolase
• 由来する生物種: Solanum lycopersicum
• 細胞内の位置: Secreted: P05119
• タンパク質・核酸の鎖数: 4
• 化学式量合計: 54641.84

構造登録者

Barrette-Ng, I.H.,Ng, K.K.-S.,Cherney, M.M.,Pearce, G.,Ghani, U.,Ryan, C.A.,James, M.N.G. (登録日: 2003-06-03, 公開日: 2003-09-16, 最終更新日: 2024-10-16)

主引用文献

Barrette-Ng, I.H.,Ng, K.K.-S.,Cherney, M.M.,Pearce, G.,Ghani, U.,Ryan, C.A.,James, M.N.G.
Unbound form of tomato inhibitor-II reveals interdomain flexibility and conformational variability in the reactive site loops
J.Biol.Chem., 278:31391-31400, 2003

PubMed Abstract: The Potato II (Pot II) family of proteinase inhibitors plays important roles in the constitutive and inducible defense of plants against predation by a wide range of pests. The structural basis of inhibition by a multidomain Pot II family inhibitor was revealed recently by the structure of the ternary complex between the two-headed tomato inhibitor-II (TI-II) and two molecules of subtilisin Carlsberg. Here we report the 2.15-A resolution crystal structure of the unbound form of TI-II that reveals significant conformational flexibility in the absence of bound proteinase molecules. The four independent copies of unbound TI-II in the asymmetric unit of the unit cell display a range of different conformations when compared with the bound form of the inhibitor, most strikingly in the orientations of the inhibitory domains and in the conformations of the reactive site loops. One of the two linker segments (residues 74 to 79) between the two domains as well as the adjacent beta-strand in Domain I (residues 80-85) is well ordered in all four copies of the unbound inhibitor, even though this region appeared to be disordered in the structure of the ternary complex. Conformational flexibility seen in the reactive site loops of unbound TI-II suggests a mechanism by which the inhibitor can balance the need for tight binding with the need for broad inhibitory function.

PubMed: 12788916
DOI: 10.1074/jbc.M304562200

実験手法

X-RAY DIFFRACTION (2.15 Å)