3ICH

Crystal structure of cyclophilin B at 1.2 A resolution

3ICH の概要

• エントリーDOI: 10.2210/pdb3ich/pdb
• 関連するPDBエントリー: 3ICI
• 分子名称: Peptidyl-prolyl cis-trans isomerase B (2 entities in total)
• 機能のキーワード: beta sandwich, cyclosporin, endoplasmic reticulum, glycoprotein, isomerase, rotamase
• 由来する生物種: Homo sapiens (human)
• 細胞内の位置: Endoplasmic reticulum lumen: P23284
• タンパク質・核酸の鎖数: 1
• 化学式量合計: 20735.79

構造登録者

Kozlov, G.,Gehring, K. (登録日: 2009-07-17, 公開日: 2010-07-21, 最終更新日: 2023-09-06)

主引用文献

Kozlov, G.,Bastos-Aristizabal, S.,Maattanen, P.,Rosenauer, A.,Zheng, F.,Killikelly, A.,Trempe, J.F.,Thomas, D.Y.,Gehring, K.
Structural Basis of Cyclophilin B Binding by the Calnexin/Calreticulin P-domain.
J.Biol.Chem., 285:35551-35557, 2010

PubMed Abstract: Little is known about how chaperones in the endoplasmic reticulum are organized into complexes to assist in the proper folding of secreted proteins. One notable exception is the complex of ERp57 and calnexin that functions as part the calnexin cycle to direct disulfide bond formation in N-glycoproteins. Here, we report three new complexes composed of the peptidyl prolyl cis-trans-isomerase cyclophilin B and any of the lectin chaperones: calnexin, calreticulin, or calmegin. The 1.7 Å crystal structure of cyclophilin with the proline-rich P-domain of calmegin reveals that binding is mediated by the same surface that binds ERp57. We used NMR titrations and mutagenesis to measure low micromolar binding of cyclophilin to all three lectin chaperones and identify essential interfacial residues. The immunosuppressant cyclosporin A did not affect complex formation, confirming the functional independence of the P-domain binding and proline isomerization sites of cyclophilin. Our results reveal the P-domain functions as a unique protein-protein interaction domain and implicate a peptidyl prolyl isomerase as a new element in the calnexin cycle.

PubMed: 20801878
DOI: 10.1074/jbc.M110.160101

実験手法

X-RAY DIFFRACTION (1.2 Å)