2QTO

An anisotropic model for potassium channel KcsA

2QTO の概要

• エントリーDOI: 10.2210/pdb2qto/pdb
• 関連するPDBエントリー: 1BL8
• 分子名称: Voltage-gated potassium channel, POTASSIUM ION (3 entities in total)
• 機能のキーワード: potassium channel, membrane proteins, normal-mode refinement, anisotropic thermal factors, metal transport, membrane protein
• 由来する生物種: Streptomyces lividans
• 細胞内の位置: Cell membrane; Multi-pass membrane protein: P0A334
• タンパク質・核酸の鎖数: 4
• 化学式量合計: 41129.13

構造登録者

Chen, X.,Poon, B.K.,Dousis, A.,Wang, Q.,Ma, J. (登録日: 2007-08-02, 公開日: 2007-09-25, 最終更新日: 2023-08-30)

主引用文献

Chen, X.,Poon, B.K.,Dousis, A.,Wang, Q.,Ma, J.
Normal-mode refinement of anisotropic thermal parameters for potassium channel KcsA at 3.2 A crystallographic resolution
Structure, 15:955-962, 2007

PubMed Abstract: We report a normal-mode method for anisotropic refinement of membrane-protein structures, based on a hypothesis that the global near-native-state disordering of membrane proteins in crystals follows low-frequency normal modes. Thus, a small set of modes is sufficient to represent the anisotropic thermal motions in X-ray crystallographic refinement. By applying the method to potassium channel KcsA at 3.2 A, we obtained a structural model with an improved fit with the diffraction data. Moreover, the improved electron density maps allowed for large structural adjustments for 12 residues in each subunit, including the rebuilding of 3 missing side chains. Overall, the anisotropic KcsA structure at 3.2 A was systematically closer to a 2.0 A KcsA structure, especially in the selectivity filter. Furthermore, the anisotropic thermal ellipsoids from the refinement revealed functionally relevant structural flexibility. We expect this method to be a valuable tool for structural refinement of many membrane proteins with moderate-resolution diffraction data.

PubMed: 17698000
DOI: 10.1016/j.str.2007.06.012

実験手法

X-RAY DIFFRACTION (3.201 Å)