National Institutes of Health/National Institute of General Medical Sciences (NIH/NIGMS)
R01GM072804
米国
National Institutes of Health/National Institute of Arthritis and Musculoskeletal and Skin Diseases (NIH/NIAMS)
R21AR063255
米国
National Institutes of Health/National Institute of Neurological Disorders and Stroke (NIH/NINDS)
R21NS106968
米国
American Heart Association
16GRNT2972000
米国
National Institutes of Health/National Institute of General Medical Sciences (NIH/NIGMS)
R01GM080139
米国
National Science Foundation (NSF, United States)
DBI-1356306
米国
引用
ジャーナル: Cell Res / 年: 2018 タイトル: Cryo-EM reveals ligand induced allostery underlying InsPR channel gating. 著者: Guizhen Fan / Mariah R Baker / Zhao Wang / Alexander B Seryshev / Steven J Ludtke / Matthew L Baker / Irina I Serysheva / 要旨: Inositol-1,4,5-trisphosphate receptors (InsPRs) are cation channels that mobilize Ca from intracellular stores in response to a wide range of cellular stimuli. The paradigm of InsPR activation is the ...Inositol-1,4,5-trisphosphate receptors (InsPRs) are cation channels that mobilize Ca from intracellular stores in response to a wide range of cellular stimuli. The paradigm of InsPR activation is the coupled interplay between binding of InsP and Ca that switches the ion conduction pathway between closed and open states to enable the passage of Ca through the channel. However, the molecular mechanism of how the receptor senses and decodes ligand-binding signals into gating motion remains unknown. Here, we present the electron cryo-microscopy structure of InsPR1 from rat cerebellum determined to 4.1 Å resolution in the presence of activating concentrations of Ca and adenophostin A (AdA), a structural mimetic of InsP and the most potent known agonist of the channel. Comparison with the 3.9 Å-resolution structure of InsPR1 in the Apo-state, also reported herein, reveals the binding arrangement of AdA in the tetrameric channel assembly and striking ligand-induced conformational rearrangements within cytoplasmic domains coupled to the dilation of a hydrophobic constriction at the gate. Together, our results provide critical insights into the mechanistic principles by which ligand-binding allosterically gates InsPR channel.
想定した対称性 - 点群: C4 (4回回転対称) / 解像度のタイプ: BY AUTHOR / 解像度: 3.9 Å / 解像度の算出法: FSC 0.143 CUT-OFF / ソフトウェア - 名称: RELION (ver. 1.4) 詳細: Image processing was performed independently using RELION and EMAN2 to near-atomic resolution in large regions of the structure. Local resolution assessment performed independently for each ...詳細: Image processing was performed independently using RELION and EMAN2 to near-atomic resolution in large regions of the structure. Local resolution assessment performed independently for each map revealed different domains were better resolved by each software package. To avoid human bias and extract the most information from each reconstruction the final map was a locally filtered average of the EMAN2 and RELION map. To combine the two maps, a local resolution filter, based on a windowed FSC local resolution assessment, was performed independently on the two maps. The two locally filtered maps were then averaged together. The local filtration determines the contribution of each map at each resolution in each region of the final composite map, permitting each map to dominate in regions where better self-consistency was obtained during refinement. 使用した粒子像数: 65438
初期 角度割当
タイプ: MAXIMUM LIKELIHOOD / ソフトウェア - 名称: RELION (ver. 1.4)
最終 角度割当
タイプ: MAXIMUM LIKELIHOOD / ソフトウェア - 名称: RELION (ver. 1.4)
最終 3次元分類
クラス数: 5 / ソフトウェア - 名称: RELION (ver. 1.4)
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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
得られたモデル
PDB-6mu2: Structure of full-length IP3R1 channel in the Apo-state