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.
想定した対称性 - 点群: C6 (6回回転対称) / 解像度のタイプ: BY AUTHOR / 解像度: 3.66 Å / 解像度の算出法: FSC 0.143 CUT-OFF / ソフトウェア - 名称: RELION 詳細: The cryo-EM density corresponding to the pore domain was resolved to 3.66 A after performing focused 3D refinement with signal subtraction and C6 symmetry. 使用した粒子像数: 34674
初期 角度割当
タイプ: MAXIMUM LIKELIHOOD / ソフトウェア - 名称: RELION
最終 角度割当
タイプ: MAXIMUM LIKELIHOOD / ソフトウェア - 名称: RELION
FSC曲線 (解像度の算出)
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原子モデル構築 1
精密化
プロトコル: AB INITIO MODEL
得られたモデル
PDB-6g8z: Structure of the pore domain of homomeric mLRRC8A volume-regulated anion channel at 3.66 A resolution