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-Structure paper
タイトル | Molecular structure of an open human K channel. |
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ジャーナル・号・ページ | Proc Natl Acad Sci U S A, Vol. 118, Issue 48, Year 2021 |
掲載日 | 2021年11月30日 |
著者 | Chen Zhao / Roderick MacKinnon / |
PubMed 要旨 | K channels are metabolic sensors that translate intracellular ATP/ADP balance into membrane excitability. The molecular composition of K includes an inward-rectifier potassium channel (Kir) and an ...K channels are metabolic sensors that translate intracellular ATP/ADP balance into membrane excitability. The molecular composition of K includes an inward-rectifier potassium channel (Kir) and an ABC transporter-like sulfonylurea receptor (SUR). Although structures of K have been determined in many conformations, in all cases, the pore in Kir is closed. Here, we describe human pancreatic K (hK) structures with an open pore at 3.1- to 4.0-Å resolution using single-particle cryo-electron microscopy (cryo-EM). Pore opening is associated with coordinated structural changes within the ATP-binding site and the channel gate in Kir. Conformational changes in SUR are also observed, resulting in an area reduction of contact surfaces between SUR and Kir. We also observe that pancreatic hK exhibits the unique (among inward-rectifier channels) property of PIP-independent opening, which appears to be correlated with a docked cytoplasmic domain in the absence of PIP. |
リンク | Proc Natl Acad Sci U S A / PubMed:34815345 / PubMed Central |
手法 | EM (単粒子) |
解像度 | 3.1 - 4.0 Å |
構造データ | EMDB-24839, PDB-7s5t: EMDB-24840, PDB-7s5v: EMDB-24842, PDB-7s5x: EMDB-24843, PDB-7s5y: EMDB-24844, PDB-7s5z: EMDB-24845, PDB-7s60: EMDB-24846, PDB-7s61: |
化合物 | ChemComp-K: ChemComp-ADP: ChemComp-MG: ChemComp-ATP: |
由来 |
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キーワード | MEMBRANE PROTEIN / ion channel / KATP / ATP-sensitive potassium channel |