ジャーナル: Nature / 年: 2018 タイトル: Structure of a volume-regulated anion channel of the LRRC8 family. 著者: Dawid Deneka / Marta Sawicka / Andy K M Lam / Cristina Paulino / Raimund Dutzler / 要旨: Volume-regulated anion channels are activated in response to hypotonic stress. These channels are composed of closely related paralogues of the leucine-rich repeat-containing protein 8 (LRRC8) family ...Volume-regulated anion channels are activated in response to hypotonic stress. These channels are composed of closely related paralogues of the leucine-rich repeat-containing protein 8 (LRRC8) family that co-assemble to form hexameric complexes. Here, using cryo-electron microscopy and X-ray crystallography, we determine the structure of a homomeric channel of the obligatory subunit LRRC8A. This protein conducts ions and has properties in common with endogenous heteromeric channels. Its modular structure consists of a transmembrane pore domain followed by a cytoplasmic leucine-rich repeat domain. The transmembrane domain, which is structurally related to connexin proteins, is wide towards the cytoplasm but constricted on the outside by a structural unit that acts as a selectivity filter. An excess of basic residues in the filter and throughout the pore attracts anions by electrostatic interaction. Our work reveals the previously unknown architecture of volume-regulated anion channels and their mechanism of selective anion conduction.
平均露光時間: 13 sec. / 電子線照射量: 1.1 e/Å2 / 検出モード: SUPER-RESOLUTION フィルム・検出器のモデル: GATAN K2 SUMMIT (4k x 4k) 実像数: 3023
画像スキャン
動画フレーム数/画像: 65 / 利用したフレーム数/画像: 1-65
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解析
ソフトウェア
名称: PHENIX / バージョン: 1.13_2998: / 分類: 精密化
EMソフトウェア
ID
名称
カテゴリ
1
RELION
粒子像選択
2
SerialEM
画像取得
4
CTFFIND
CTF補正
7
Coot
モデルフィッティング
9
RELION
初期オイラー角割当
10
RELION
最終オイラー角割当
12
RELION
3次元再構成
13
PHENIX
モデル精密化
14
REFMAC
モデル精密化
CTF補正
タイプ: PHASE FLIPPING AND AMPLITUDE CORRECTION
粒子像の選択
選択した粒子像数: 105867
対称性
点対称性: C3 (3回回転対称)
3次元再構成
解像度: 4.25 Å / 解像度の算出法: FSC 0.143 CUT-OFF / 粒子像の数: 34674 詳細: The cryo-EM density corresponding to the full-length mLRRC8A was resolved to 4.25 A in the presence of a soft solvent mask and after applying global C3 symmetry. 対称性のタイプ: POINT