+データを開く
-基本情報
登録情報 | データベース: PDB / ID: 2w4v | ||||||
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タイトル | Isometrically contracting insect asynchronous flight muscle quick frozen after a quick release step | ||||||
要素 |
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キーワード | CONTRACTILE PROTEIN / TROPOMYOSIN / LIGHT CHAINS / ACTIN-BINDING / ISOMETRIC CONTRACTION / THIN FILAMENT / MOTOR PROTEIN / THICK FILAMENT / MUSCLE PROTEIN | ||||||
機能・相同性 | 機能・相同性情報 muscle myosin complex / myosin filament / myosin II complex / myosin complex / sarcomere organization / microfilament motor activity / myofibril / muscle contraction / actin filament binding / calmodulin binding ...muscle myosin complex / myosin filament / myosin II complex / myosin complex / sarcomere organization / microfilament motor activity / myofibril / muscle contraction / actin filament binding / calmodulin binding / calcium ion binding / ATP binding 類似検索 - 分子機能 | ||||||
生物種 | ARGOPECTEN IRRADIANS (無脊椎動物) | ||||||
手法 | 電子顕微鏡法 / 電子線トモグラフィー法 / 解像度: 35 Å | ||||||
データ登録者 | Wu, S. / Liu, J. / Reedy, M.C. / Tregear, R.T. / Winkler, H. / Franzini-Armstrong, C. / Sasaki, H. / Lucaveche, C. / Goldman, Y.E. / Reedy, M.K. / Taylor, K.A. | ||||||
引用 | ジャーナル: PLoS One / 年: 2012 タイトル: Structural changes in isometrically contracting insect flight muscle trapped following a mechanical perturbation. 著者: Shenping Wu / Jun Liu / Mary C Reedy / Robert J Perz-Edwards / Richard T Tregear / Hanspeter Winkler / Clara Franzini-Armstrong / Hiroyuki Sasaki / Carmen Lucaveche / Yale E Goldman / Michael ...著者: Shenping Wu / Jun Liu / Mary C Reedy / Robert J Perz-Edwards / Richard T Tregear / Hanspeter Winkler / Clara Franzini-Armstrong / Hiroyuki Sasaki / Carmen Lucaveche / Yale E Goldman / Michael K Reedy / Kenneth A Taylor / 要旨: The application of rapidly applied length steps to actively contracting muscle is a classic method for synchronizing the response of myosin cross-bridges so that the average response of the ensemble ...The application of rapidly applied length steps to actively contracting muscle is a classic method for synchronizing the response of myosin cross-bridges so that the average response of the ensemble can be measured. Alternatively, electron tomography (ET) is a technique that can report the structure of the individual members of the ensemble. We probed the structure of active myosin motors (cross-bridges) by applying 0.5% changes in length (either a stretch or a release) within 2 ms to isometrically contracting insect flight muscle (IFM) fibers followed after 5-6 ms by rapid freezing against a liquid helium cooled copper mirror. ET of freeze-substituted fibers, embedded and thin-sectioned, provides 3-D cross-bridge images, sorted by multivariate data analysis into ~40 classes, distinct in average structure, population size and lattice distribution. Individual actin subunits are resolved facilitating quasi-atomic modeling of each class average to determine its binding strength (weak or strong) to actin. ~98% of strong-binding acto-myosin attachments present after a length perturbation are confined to "target zones" of only two actin subunits located exactly midway between successive troponin complexes along each long-pitch helical repeat of actin. Significant changes in the types, distribution and structure of actin-myosin attachments occurred in a manner consistent with the mechanical transients. Most dramatic is near disappearance, after either length perturbation, of a class of weak-binding cross-bridges, attached within the target zone, that are highly likely to be precursors of strong-binding cross-bridges. These weak-binding cross-bridges were originally observed in isometrically contracting IFM. Their disappearance following a quick stretch or release can be explained by a recent kinetic model for muscle contraction, as behaviour consistent with their identification as precursors of strong-binding cross-bridges. The results provide a detailed model for contraction in IFM that may be applicable to contraction in other types of muscle. #1: ジャーナル: J Struct Biol / 年: 2009 タイトル: Methods for identifying and averaging variable molecular conformations in tomograms of actively contracting insect flight muscle. 著者: Shenping Wu / Jun Liu / Mary C Reedy / Hanspeter Winkler / Michael K Reedy / Kenneth A Taylor / 要旨: During active muscle contraction, tension is generated through many simultaneous, independent interactions between the molecular motor myosin and the actin filaments. The ensemble of myosin motors ...During active muscle contraction, tension is generated through many simultaneous, independent interactions between the molecular motor myosin and the actin filaments. The ensemble of myosin motors displays heterogeneous conformations reflecting different mechanochemical steps of the ATPase pathway. We used electron tomography of actively contracting insect flight muscle fast-frozen, freeze substituted, Araldite embedded, thin-sectioned and stained, to obtain 3D snapshots of the multiplicity of actin-attached myosin structures. We describe procedures for alignment of the repeating lattice of sub-volumes (38.7 nm cross-bridge repeats bounded by troponin) and multivariate data analysis to identify self-similar repeats for computing class averages. Improvements in alignment and classification of repeat sub-volumes reveals (for the first time in active muscle images) the helix of actin subunits in the thin filament and the troponin density with sufficient clarity that a quasiatomic model of the thin filament can be built into the class averages independent of the myosin cross-bridges. We show how quasiatomic model building can identify both strong and weak myosin attachments to actin. We evaluate the accuracy of image classification to enumerate the different types of actin-myosin attachments. | ||||||
履歴 |
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-構造の表示
ムービー |
ムービービューア |
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構造ビューア | 分子: MolmilJmol/JSmol |
-ダウンロードとリンク
-ダウンロード
PDBx/mmCIF形式 | 2w4v.cif.gz | 4.5 MB | 表示 | PDBx/mmCIF形式 |
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PDB形式 | pdb2w4v.ent.gz | 3.7 MB | 表示 | PDB形式 |
PDBx/mmJSON形式 | 2w4v.json.gz | ツリー表示 | PDBx/mmJSON形式 | |
その他 | その他のダウンロード |
-検証レポート
文書・要旨 | 2w4v_validation.pdf.gz | 1 MB | 表示 | wwPDB検証レポート |
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文書・詳細版 | 2w4v_full_validation.pdf.gz | 8.3 MB | 表示 | |
XML形式データ | 2w4v_validation.xml.gz | 1.8 MB | 表示 | |
CIF形式データ | 2w4v_validation.cif.gz | 2.3 MB | 表示 | |
アーカイブディレクトリ | https://data.pdbj.org/pub/pdb/validation_reports/w4/2w4v ftp://data.pdbj.org/pub/pdb/validation_reports/w4/2w4v | HTTPS FTP |
-関連構造データ
-リンク
-集合体
登録構造単位 |
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1 |
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モデル数 | 27 |
-要素
#1: タンパク質 | 分子量: 94843.883 Da / 分子数: 1 / 断片: RESIDUES 5-835 / 由来タイプ: 天然 / 詳細: MYOSIN S1 HEAVY CHAIN / 由来: (天然) ARGOPECTEN IRRADIANS (無脊椎動物) / 参照: UniProt: P24733 |
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#2: タンパク質 | 分子量: 15575.700 Da / 分子数: 1 / 断片: RESIDUES 16-151 / 由来タイプ: 天然 詳細: MYOSIN REGULATORY LIGHT CHAIN, RLC, STRIATED ADDUCTOR MUSCLE 由来: (天然) ARGOPECTEN IRRADIANS (無脊椎動物) / 参照: UniProt: P13543 |
#3: タンパク質 | 分子量: 17051.912 Da / 分子数: 1 / 断片: RESIDUES 5-155 / 由来タイプ: 天然 詳細: MYOSIN ESSENTIAL LIGHT CHAIN, ELC, STRIATED ADDUCTOR MUSCLE 由来: (天然) ARGOPECTEN IRRADIANS (無脊椎動物) / 参照: UniProt: P07291 |
配列の詳細 | 92 IDENTITY TO P24733 100 IDENTITY TO P13543 100 IDENTITY TO P07291 |
-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: TISSUE / 3次元再構成法: 電子線トモグラフィー法 |
-試料調製
構成要素 | 名称: INSECT FIBRILLAR FLIGHT MUSCLE / タイプ: TISSUE 詳細: THIS SPECIMEN IS OBTAINED FROM A QUICK FROZEN, ISOMETRICALLY CONTRACTING ASYNCHRONOUS INSECT FLIGHT MUSCLE THAT HAS BEEN FREEZE SUBSTITUTED, PLASTIC EMBEDDED, AND THIN SECTIONED. THE FIBERS ...詳細: THIS SPECIMEN IS OBTAINED FROM A QUICK FROZEN, ISOMETRICALLY CONTRACTING ASYNCHRONOUS INSECT FLIGHT MUSCLE THAT HAS BEEN FREEZE SUBSTITUTED, PLASTIC EMBEDDED, AND THIN SECTIONED. THE FIBERS FOR THIS STUDY WERE SUBJECTED TO MECHANICAL TRANSIENTS. FOR THE QUICK RELEASE,THE FIBER WAS RELEASED 9 NM PER HALF-SARCOMERE IN 2 MS AND THE FREEZING IMPACT - OCC-6 MS LATER. |
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緩衝液 | 名称: 20 MM MOPS BUFFER, 5 MM NAN3, AND MGCL2, ATP, CACL2, AND EGTA IN VARYING MILLIMOLAR CONCENTRATIONS 詳細: 20 MM MOPS BUFFER, 5 MM NAN3, AND MGCL2, ATP, CACL2, AND EGTA IN VARYING MILLIMOLAR CONCENTRATIONS |
試料 | 包埋: YES / シャドウイング: NO / 染色: NO / 凍結: NO |
試料支持 | 詳細: CARBON |
急速凍結 | 装置: HOMEMADE PLUNGER / 凍結剤: HELIUM 詳細: SMASH AGAINST A LIQUID HELIUM COOLED GOLD COATED COPPER MIRROR |
-電子顕微鏡撮影
顕微鏡 | モデル: FEI/PHILIPS CM300FEG/T |
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電子銃 | 電子線源: FIELD EMISSION GUN / 加速電圧: 300 kV / 照射モード: FLOOD BEAM |
電子レンズ | モード: BRIGHT FIELD / Cs: 2 mm |
試料ホルダ | 傾斜角・最大: 72 ° / 傾斜角・最小: -72 ° |
撮影 | フィルム・検出器のモデル: TVIPS TEMCAM-F224 (2k x 2k) |
放射波長 | 相対比: 1 |
-解析
対称性 | 点対称性: C1 (非対称) | ||||||||||||
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3次元再構成 | 解像度の算出法: FSC 0.5 CUT-OFF 詳細: NOTE THAT OUR LOWEST RESOLUTION DATA IS AT INVERSE 1 MICRON. NUMBER OF FOURIER COEFFICIENTS IS ALMOST A HALF MILLION. THESE COORDINATES WERE FITTED TO AVERAGED SUBVOLUMES OBTAINED FROM A DUAL ...詳細: NOTE THAT OUR LOWEST RESOLUTION DATA IS AT INVERSE 1 MICRON. NUMBER OF FOURIER COEFFICIENTS IS ALMOST A HALF MILLION. THESE COORDINATES WERE FITTED TO AVERAGED SUBVOLUMES OBTAINED FROM A DUAL AXIS TOMOGRAM. THE FITTING WAS DONE MANUALLY USING THE CRYSTALLOGRAPHIC MODEL FITTING PROGRAM O. THERE ARE 27 MODELS. 対称性のタイプ: POINT | ||||||||||||
精密化 | 最高解像度: 35 Å | ||||||||||||
精密化ステップ | サイクル: LAST / 最高解像度: 35 Å
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