ジャーナル: Science / 年: 2019 タイトル: The structure of a membrane adenylyl cyclase bound to an activated stimulatory G protein. 著者: Chao Qi / Simona Sorrentino / Ohad Medalia / Volodymyr M Korkhov / 要旨: Membrane-integral adenylyl cyclases (ACs) are key enzymes in mammalian heterotrimeric GTP-binding protein (G protein)-dependent signal transduction, which is important in many cellular processes. ...Membrane-integral adenylyl cyclases (ACs) are key enzymes in mammalian heterotrimeric GTP-binding protein (G protein)-dependent signal transduction, which is important in many cellular processes. Signals received by the G protein-coupled receptors are conveyed to ACs through G proteins to modulate the levels of cellular cyclic adenosine monophosphate (cAMP). Here, we describe the cryo-electron microscopy structure of the bovine membrane AC9 bound to an activated G protein αs subunit at 3.4-angstrom resolution. The structure reveals the organization of the membrane domain and helical domain that spans between the membrane and catalytic domains of AC9. The carboxyl-terminal extension of the catalytic domain occludes both the catalytic and the allosteric sites of AC9, inducing a conformation distinct from the substrate- and activator-bound state, suggesting a regulatory role in cAMP production.
モデルのタイプ: OTHER / 詳細: Initial model generated using cryoSPARC
最終 再構成
想定した対称性 - 点群: C1 (非対称) / 解像度のタイプ: BY AUTHOR / 解像度: 3.6 Å / 解像度の算出法: FSC 0.143 CUT-OFF / ソフトウェア - 名称: RELION (ver. 2.1.0) 詳細: Continued refinement using a mask excluding the membrane portion of the AC9 and the G protein 使用した粒子像数: 16343
初期 角度割当
タイプ: MAXIMUM LIKELIHOOD / ソフトウェア - 名称: RELION (ver. 2.1.0)
最終 角度割当
タイプ: MAXIMUM LIKELIHOOD / ソフトウェア - 名称: RELION (ver. 2.1.0)
最終 3次元分類
クラス数: 3 / ソフトウェア - 名称: RELION (ver. 2.1.0)
FSC曲線 (解像度の算出)
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原子モデル構築 1
精密化
空間: REAL / プロトコル: AB INITIO MODEL / 温度因子: 149.61 当てはまり具合の基準: Cross-correlation coefficient