2ZA4

Crystal Structural Analysis of Barnase-barstar Complex

2ZA4 の概要

• エントリーDOI: 10.2210/pdb2za4/pdb
• 関連するPDBエントリー: 1X1U 1X1W 1X1X 1X1Y
• 分子名称: Ribonuclease, Barstar, CHLORIDE ION, ... (4 entities in total)
• 機能のキーワード: protein-protein complex, endonuclease, genetically modified food, hydrolase, nuclease, secreted, cytoplasm, hydrolase-hydrolase inhibitor complex, hydrolase/hydrolase inhibitor
• 由来する生物種: Bacillus amyloliquefaciens; 詳細
• 細胞内の位置: Secreted: P00648; Cytoplasm: P11540
• タンパク質・核酸の鎖数: 4
• 化学式量合計: 45241.34

構造登録者

Urakubo, Y.,Ikura, T.,Ito, N. (登録日: 2007-10-01, 公開日: 2008-05-20, 最終更新日: 2023-11-01)

主引用文献

Urakubo, Y.,Ikura, T.,Ito, N.
Crystal structural analysis of protein-protein interactions drastically destabilized by a single mutation
Protein Sci., 17:1055-1065, 2008

PubMed Abstract: The complex of barnase (bn) and barstar (bs), which has been widely studied as a model for quantitative analysis of protein-protein interactions, is significantly destabilized by a single mutation, namely, bs Asp39 --> Ala, which corresponds to a change of 7.7 kcal x mol(-1) in the free energy of binding. However, there has been no structural information available to explain such a drastic destabilization. In the present study, we determined the structure of the mutant complex at 1.58 A resolution by X-ray crystallography. The complex was similar to the wild-type complex in terms of overall and interface structures; however, the hydrogen bond network mediated by water molecules at the interface was significantly different. Several water molecules filled the cavity created by the mutation and consequently caused rearrangement of the hydrated water molecules at the interface. The water molecules were redistributed into a channel-like structure that penetrated into the complex. Furthermore, molecular dynamics simulations showed that the mutation increased the mobility of water molecules at the interface. Since such a drastic change in hydration was not observed in other mutant complexes of bn and bs, the significant destabilization of the interaction may be due to this channel-like structure of hydrated water molecules.

PubMed: 18441234
DOI: 10.1110/ps.073322508

実験手法

X-RAY DIFFRACTION (1.58 Å)