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Open data
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Basic information
Entry | Database: PDB / ID: 8act | ||||||||||||
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Title | structure of the human beta-cardiac myosin folded-back off state | ||||||||||||
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![]() | CONTRACTILE PROTEIN / Cardiac Myosin / Myosin / Human / folded-back off state | ||||||||||||
Function / homology | ![]() myosin II heavy chain binding / muscle cell fate specification / regulation of slow-twitch skeletal muscle fiber contraction / regulation of the force of skeletal muscle contraction / regulation of striated muscle contraction / cardiac myofibril / muscle myosin complex / cardiac myofibril assembly / regulation of the force of heart contraction / transition between fast and slow fiber ...myosin II heavy chain binding / muscle cell fate specification / regulation of slow-twitch skeletal muscle fiber contraction / regulation of the force of skeletal muscle contraction / regulation of striated muscle contraction / cardiac myofibril / muscle myosin complex / cardiac myofibril assembly / regulation of the force of heart contraction / transition between fast and slow fiber / myosin filament / adult heart development / positive regulation of ATP-dependent activity / cardiac muscle hypertrophy in response to stress / Striated Muscle Contraction / muscle filament sliding / myosin complex / myosin II complex / A band / I band / structural constituent of muscle / ventricular cardiac muscle tissue morphogenesis / microfilament motor activity / myosin heavy chain binding / heart contraction / positive regulation of the force of heart contraction / myofibril / actin monomer binding / skeletal muscle contraction / striated muscle contraction / ATP metabolic process / stress fiber / cardiac muscle contraction / muscle contraction / regulation of heart rate / sarcomere / negative regulation of cell growth / Z disc / actin filament binding / heart development / cytoskeleton / calmodulin binding / calcium ion binding / ATP binding / cytosol / cytoplasm Similarity search - Function | ||||||||||||
Biological species | ![]() | ||||||||||||
Method | ELECTRON MICROSCOPY / single particle reconstruction / cryo EM / Resolution: 3.6 Å | ||||||||||||
![]() | Grinzato, A. / Kandiah, E. / Robert-Paganin, J. / Auguin, D. / Kikuti, C. / Nandwani, N. / Moussaoui, D. / Pathak, D. / Ruppel, K.M. / Spudich, J.A. / Houdusse, A. | ||||||||||||
Funding support | ![]() ![]()
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![]() | ![]() Title: Cryo-EM structure of the folded-back state of human β-cardiac myosin. Authors: Alessandro Grinzato / Daniel Auguin / Carlos Kikuti / Neha Nandwani / Dihia Moussaoui / Divya Pathak / Eaazhisai Kandiah / Kathleen M Ruppel / James A Spudich / Anne Houdusse / Julien Robert-Paganin / ![]() ![]() Abstract: To save energy and precisely regulate cardiac contractility, cardiac muscle myosin heads are sequestered in an 'off' state that can be converted to an 'on' state when exertion is increased. The 'off' ...To save energy and precisely regulate cardiac contractility, cardiac muscle myosin heads are sequestered in an 'off' state that can be converted to an 'on' state when exertion is increased. The 'off' state is equated with a folded-back structure known as the interacting-heads motif (IHM), which is a regulatory feature of all class-2 muscle and non-muscle myosins. We report here the human β-cardiac myosin IHM structure determined by cryo-electron microscopy to 3.6 Å resolution, providing details of all the interfaces stabilizing the 'off' state. The structure shows that these interfaces are hot spots of hypertrophic cardiomyopathy mutations that are thought to cause hypercontractility by destabilizing the 'off' state. Importantly, the cardiac and smooth muscle myosin IHM structures dramatically differ, providing structural evidence for the divergent physiological regulation of these muscle types. The cardiac IHM structure will facilitate development of clinically useful new molecules that modulate IHM stability. | ||||||||||||
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Structure visualization
Structure viewer | Molecule: ![]() ![]() |
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PDBx/mmCIF format | ![]() | 419.4 KB | Display | ![]() |
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PDB format | ![]() | 340.9 KB | Display | ![]() |
PDBx/mmJSON format | ![]() | Tree view | ![]() | |
Others | ![]() |
-Validation report
Arichive directory | ![]() ![]() | HTTPS FTP |
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-Related structure data
Related structure data | ![]() 15353MC M: map data used to model this data C: citing same article ( |
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Similar structure data | Similarity search - Function & homology ![]() |
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Assembly
Deposited unit | ![]()
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Components
-Protein , 3 types, 6 molecules ABCDEF
#1: Protein | Mass: 103807.148 Da / Num. of mol.: 2 Source method: isolated from a genetically manipulated source Source: (gene. exp.) ![]() ![]() #2: Protein | Mass: 17895.398 Da / Num. of mol.: 2 Source method: isolated from a genetically manipulated source Source: (gene. exp.) ![]() ![]() #3: Protein | Mass: 16490.580 Da / Num. of mol.: 2 Source method: isolated from a genetically manipulated source Source: (gene. exp.) ![]() ![]() |
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-Non-polymers , 3 types, 6 molecules 




#4: Chemical | #5: Chemical | #6: Chemical | |
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-Details
Has ligand of interest | Y |
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-Experimental details
-Experiment
Experiment | Method: ELECTRON MICROSCOPY |
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EM experiment | Aggregation state: PARTICLE / 3D reconstruction method: single particle reconstruction |
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Sample preparation
Component | Name: human beta-cardiac myosin folded-back off state / Type: COMPLEX / Entity ID: #1-#3 / Source: NATURAL |
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Source (natural) | Organism: ![]() |
Buffer solution | pH: 7.5 |
Specimen | Conc.: 0.3 mg/ml / Embedding applied: NO / Shadowing applied: NO / Staining applied: NO / Vitrification applied: YES |
Vitrification | Cryogen name: ETHANE |
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Electron microscopy imaging
Experimental equipment | ![]() Model: Titan Krios / Image courtesy: FEI Company |
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Microscopy | Model: FEI TITAN KRIOS |
Electron gun | Electron source: ![]() |
Electron lens | Mode: BRIGHT FIELD / Nominal defocus max: 2200 nm / Nominal defocus min: 800 nm |
Image recording | Electron dose: 40 e/Å2 / Film or detector model: GATAN K3 BIOQUANTUM (6k x 4k) |
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Processing
Software | Name: PHENIX / Version: 1.19.2_4158: / Classification: refinement | ||||||||||||||||||||||||
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CTF correction | Type: PHASE FLIPPING AND AMPLITUDE CORRECTION | ||||||||||||||||||||||||
3D reconstruction | Resolution: 3.6 Å / Resolution method: FSC 0.143 CUT-OFF / Num. of particles: 213596 / Symmetry type: POINT | ||||||||||||||||||||||||
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