7UQR

Cryo-EM structure of the pancreatic ATP-sensitive potassium channel in the apo form with Kir6.2-CTD in the down conformation

7UQR の概要

• エントリーDOI: 10.2210/pdb7uqr/pdb
• 関連するPDBエントリー: 7TYS 7TYT 7U1E 7U1Q 7U1S 7U24 7U2X 7U6Y 7U7M 7UAA
• EMDBエントリー: 26320
• 分子名称: ATP-sensitive inward rectifier potassium channel 11, ATP-binding cassette sub-family C member 8 (2 entities in total)
• 機能のキーワード: katp channel, sur1, kir6.2, sulfonylurea receptor, potassium transport, membrane protein
• 由来する生物種: Rattus norvegicus (Norway rat); 詳細
• タンパク質・核酸の鎖数: 5
• 化学式量合計: 351980.63

構造登録者

Shyng, S.L.,Sung, M.W.,Driggers, C.M. (登録日: 2022-04-20, 公開日: 2022-08-31, 最終更新日: 2024-06-12)

主引用文献

Sung, M.W.,Driggers, C.M.,Mostofian, B.,Russo, J.D.,Patton, B.L.,Zuckerman, D.M.,Shyng, S.L.
Ligand-mediated Structural Dynamics of a Mammalian Pancreatic K ATP Channel.
J.Mol.Biol., 434:167789-167789, 2022

PubMed Abstract: Regulation of pancreatic K channels involves orchestrated interactions of their subunits, Kir6.2 and SUR1, and ligands. Previously we reported K channel cryo-EM structures in the presence and absence of pharmacological inhibitors and ATP, focusing on the mechanisms by which inhibitors act as pharmacological chaperones of K channels (Martin et al., 2019). Here we analyzed the same cryo-EM datasets with a focus on channel conformational dynamics to elucidate structural correlates pertinent to ligand interactions and channel gating. We found pharmacological inhibitors and ATP enrich a channel conformation in which the Kir6.2 cytoplasmic domain is closely associated with the transmembrane domain, while depleting one where the Kir6.2 cytoplasmic domain is extended away into the cytoplasm. This conformational change remodels a network of intra- and inter-subunit interactions as well as the ATP and PIP binding pockets. The structures resolved key contacts between the distal N-terminus of Kir6.2 and SUR1's ABC module involving residues implicated in channel function and showed a SUR1 residue, K134, participates in PIP binding. Molecular dynamics simulations revealed two Kir6.2 residues, K39 and R54, that mediate both ATP and PIP binding, suggesting a mechanism for competitive gating by ATP and PIP.

PubMed: 35964676
DOI: 10.1016/j.jmb.2022.167789

実験手法

ELECTRON MICROSCOPY (4.55 Å)