ジャーナル: Nat Neurosci / 年: 2005 タイトル: Cytoplasmic domain structures of Kir2.1 and Kir3.1 show sites for modulating gating and rectification. 著者: Scott Pegan / Christine Arrabit / Wei Zhou / Witek Kwiatkowski / Anthony Collins / Paul A Slesinger / Senyon Choe / 要旨: N- and C-terminal cytoplasmic domains of inwardly rectifying K (Kir) channels control the ion-permeation pathway through diverse interactions with small molecules and protein ligands in the cytoplasm. ...N- and C-terminal cytoplasmic domains of inwardly rectifying K (Kir) channels control the ion-permeation pathway through diverse interactions with small molecules and protein ligands in the cytoplasm. Two new crystal structures of the cytoplasmic domains of Kir2.1 (Kir2.1(L)) and the G protein-sensitive Kir3.1 (Kir3.1(S)) channels in the absence of PIP(2) show the cytoplasmic ion-permeation pathways occluded by four cytoplasmic loops that form a girdle around the central pore (G-loop). Significant flexibility of the pore-facing G-loop of Kir2.1(L) and Kir3.1(S) suggests a possible role as a diffusion barrier between cytoplasmic and transmembrane pores. Consistent with this, mutations of the G-loop disrupted gating or inward rectification. Structural comparison shows a di-aspartate cluster on the distal end of the cytoplasmic pore of Kir2.1(L) that is important for modulating inward rectification. Taken together, these results suggest the cytoplasmic domains of Kir channels undergo structural changes to modulate gating and inward rectification.
履歴
登録
2004年7月24日
登録サイト: RCSB / 処理サイト: RCSB
改定 1.0
2005年3月8日
Provider: repository / タイプ: Initial release
改定 1.1
2008年4月30日
Group: Version format compliance
改定 1.2
2011年7月13日
Group: Derived calculations / Version format compliance
解像度: 2.09→91.29 Å / Cor.coef. Fo:Fc: 0.95 / Cor.coef. Fo:Fc free: 0.936 / SU B: 4.589 / SU ML: 0.121 / 交差検証法: THROUGHOUT / ESU R: 0.191 / ESU R Free: 0.171 / 立体化学のターゲット値: MAXIMUM LIKELIHOOD / 詳細: HYDROGENS HAVE BEEN ADDED IN THE RIDING POSITIONS
Rfactor
反射数
%反射
Selection details
Rfree
0.23505
813
5.1 %
RANDOM
Rwork
0.19431
-
-
-
all
0.19641
15270
-
-
obs
0.19641
15270
96 %
-
溶媒の処理
イオンプローブ半径: 0.8 Å / 減衰半径: 0.8 Å / VDWプローブ半径: 1.4 Å / 溶媒モデル: BABINET MODEL WITH MASK