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データを開く
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基本情報
登録情報 | データベース: PDB / ID: 5nol | ||||||
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タイトル | Ca2+-induced Movement of Tropomyosin on Native Cardiac Thin Filaments - "Closed" state | ||||||
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![]() | MOTOR PROTEIN / F-actin / tropomyosin | ||||||
機能・相同性 | ![]() Striated Muscle Contraction / actin-myosin filament sliding / myosin binding / heart contraction / mesenchyme migration / skeletal muscle thin filament assembly / striated muscle thin filament / skeletal muscle fiber development / stress fiber / sarcomere ...Striated Muscle Contraction / actin-myosin filament sliding / myosin binding / heart contraction / mesenchyme migration / skeletal muscle thin filament assembly / striated muscle thin filament / skeletal muscle fiber development / stress fiber / sarcomere / filopodium / actin filament organization / actin filament / 加水分解酵素; 酸無水物に作用; 酸無水物に作用・細胞または細胞小器官の運動に関与 / lamellipodium / cell body / hydrolase activity / positive regulation of gene expression / ATP binding / cytoplasm 類似検索 - 分子機能 | ||||||
生物種 | ![]() ![]() | ||||||
手法 | 電子顕微鏡法 / らせん対称体再構成法 / クライオ電子顕微鏡法 / 解像度: 8 Å | ||||||
![]() | Risi, C. / Eisner, J. / Belknap, B. / Heeley, D.H. / White, H.D. / Schroeder, G.F. / Galkin, V.E. | ||||||
![]() | ![]() タイトル: Ca-induced movement of tropomyosin on native cardiac thin filaments revealed by cryoelectron microscopy. 著者: Cristina Risi / Jamie Eisner / Betty Belknap / David H Heeley / Howard D White / Gunnar F Schröder / Vitold E Galkin / ![]() ![]() ![]() 要旨: Muscle contraction relies on the interaction of myosin motors with F-actin, which is regulated through a translocation of tropomyosin by the troponin complex in response to Ca The current model of ...Muscle contraction relies on the interaction of myosin motors with F-actin, which is regulated through a translocation of tropomyosin by the troponin complex in response to Ca The current model of muscle regulation holds that at relaxing (low-Ca) conditions tropomyosin blocks myosin binding sites on F-actin, whereas at activating (high-Ca) conditions tropomyosin translocation only partially exposes myosin binding sites on F-actin so that binding of rigor myosin is required to fully activate the thin filament (TF). Here we used a single-particle approach to helical reconstruction of frozen hydrated native cardiac TFs under relaxing and activating conditions to reveal the azimuthal movement of the tropomyosin on the surface of the native cardiac TF upon Ca activation. We demonstrate that at either relaxing or activating conditions tropomyosin is not constrained in one structural state, but rather is distributed between three structural positions on the surface of the TF. We show that two of these tropomyosin positions restrain actomyosin interactions, whereas in the third position, which is significantly enhanced at high Ca, tropomyosin does not block myosin binding sites on F-actin. Our data provide a structural framework for the enhanced activation of the cardiac TF over the skeletal TF by Ca and lead to a mechanistic model for the regulation of the cardiac TF. | ||||||
履歴 |
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構造の表示
ムービー |
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構造ビューア | 分子: ![]() ![]() |
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PDBx/mmCIF形式 | ![]() | 392.8 KB | 表示 | ![]() |
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その他 | ![]() |
-検証レポート
アーカイブディレクトリ | ![]() ![]() | HTTPS FTP |
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-関連構造データ
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リンク
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集合体
登録構造単位 | ![]()
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要素
#1: タンパク質 | 分子量: 40805.457 Da / 分子数: 5 / 由来タイプ: 組換発現 / 由来: (組換発現) ![]() ![]() ![]() ![]() #2: タンパク質 | 分子量: 11507.176 Da / 分子数: 2 / 由来タイプ: 組換発現 / 由来: (組換発現) ![]() ![]() ![]() ![]() #3: 化合物 | ChemComp-ADP / #4: 化合物 | ChemComp-MG / |
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-実験情報
-実験
実験 | 手法: 電子顕微鏡法 |
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EM実験 | 試料の集合状態: HELICAL ARRAY / 3次元再構成法: らせん対称体再構成法 |
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試料調製
構成要素 | 名称: Native Cardiac Thin Filaments / タイプ: ORGANELLE OR CELLULAR COMPONENT / 詳細: Sample contains actin, tropomyosin, and troponin. / Entity ID: #1-#2 / 由来: NATURAL |
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分子量 | 実験値: NO |
由来(天然) | 生物種: ![]() ![]() |
緩衝液 | pH: 7 |
試料 | 包埋: NO / シャドウイング: NO / 染色: NO / 凍結: YES |
急速凍結 | 装置: FEI VITROBOT MARK IV / 凍結剤: ETHANE / 湿度: 95 % |
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電子顕微鏡撮影
実験機器 | ![]() モデル: Titan Krios / 画像提供: FEI Company |
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顕微鏡 | モデル: FEI TITAN KRIOS |
電子銃 | 電子線源: ![]() |
電子レンズ | モード: BRIGHT FIELD |
撮影 | 電子線照射量: 30 e/Å2 フィルム・検出器のモデル: FEI FALCON II (4k x 4k) |
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解析
EMソフトウェア |
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CTF補正 | タイプ: PHASE FLIPPING AND AMPLITUDE CORRECTION | |||||||||||||||||||||||||
らせん対称 | 回転角度/サブユニット: -166.8 ° / 軸方向距離/サブユニット: 27.4 Å / らせん対称軸の対称性: C1 | |||||||||||||||||||||||||
3次元再構成 | 解像度: 8 Å / 解像度の算出法: FSC 0.5 CUT-OFF / 粒子像の数: 12356 / 対称性のタイプ: HELICAL | |||||||||||||||||||||||||
原子モデル構築 | プロトコル: FLEXIBLE FIT / 空間: REAL / Target criteria: Cross-correlation coefficient 詳細: Rigid fitting was done with Chimera and then DireX was used for flexible fitting. |