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Yorodumi- PDB-5noj: Ca2+-induced Movement of Tropomyosin on Native Cardiac Thin Filam... -
+Open data
-Basic information
Entry | Database: PDB / ID: 5noj | ||||||
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Title | Ca2+-induced Movement of Tropomyosin on Native Cardiac Thin Filaments - "OPEN" state | ||||||
Components |
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Keywords | MOTOR PROTEIN / F-actin / tropomyosin | ||||||
Function / homology | Function and homology information Striated Muscle Contraction / mesenchyme migration / skeletal muscle thin filament assembly / striated muscle thin filament / skeletal muscle fiber development / stress fiber / filopodium / actin filament / Hydrolases; Acting on acid anhydrides; Acting on acid anhydrides to facilitate cellular and subcellular movement / lamellipodium ...Striated Muscle Contraction / mesenchyme migration / skeletal muscle thin filament assembly / striated muscle thin filament / skeletal muscle fiber development / stress fiber / filopodium / actin filament / Hydrolases; Acting on acid anhydrides; Acting on acid anhydrides to facilitate cellular and subcellular movement / lamellipodium / cell body / hydrolase activity / positive regulation of gene expression / ATP binding / cytoplasm Similarity search - Function | ||||||
Biological species | Sus scrofa (pig) | ||||||
Method | ELECTRON MICROSCOPY / helical reconstruction / cryo EM / Resolution: 11 Å | ||||||
Authors | Risi, C. / Eisner, J. / Belknap, B. / Heeley, D.H. / White, H.D. / Schroeder, G.F. / Galkin, V.E. | ||||||
Funding support | United States, 1items
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Citation | Journal: Proc Natl Acad Sci U S A / Year: 2017 Title: Ca-induced movement of tropomyosin on native cardiac thin filaments revealed by cryoelectron microscopy. Authors: Cristina Risi / Jamie Eisner / Betty Belknap / David H Heeley / Howard D White / Gunnar F Schröder / Vitold E Galkin / Abstract: 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. | ||||||
History |
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-Structure visualization
Movie |
Movie viewer |
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Structure viewer | Molecule: MolmilJmol/JSmol |
-Downloads & links
-Download
PDBx/mmCIF format | 5noj.cif.gz | 391.1 KB | Display | PDBx/mmCIF format |
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PDB format | pdb5noj.ent.gz | 328.2 KB | Display | PDB format |
PDBx/mmJSON format | 5noj.json.gz | Tree view | PDBx/mmJSON format | |
Others | Other downloads |
-Validation report
Summary document | 5noj_validation.pdf.gz | 1.1 MB | Display | wwPDB validaton report |
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Full document | 5noj_full_validation.pdf.gz | 1.2 MB | Display | |
Data in XML | 5noj_validation.xml.gz | 74.3 KB | Display | |
Data in CIF | 5noj_validation.cif.gz | 105 KB | Display | |
Arichive directory | https://data.pdbj.org/pub/pdb/validation_reports/no/5noj ftp://data.pdbj.org/pub/pdb/validation_reports/no/5noj | HTTPS FTP |
-Related structure data
Related structure data | 3666MC 3665C 3667C 5nogC 5nolC C: citing same article (ref.) M: map data used to model this data |
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Similar structure data |
-Links
-Assembly
Deposited unit |
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-Components
#1: Protein | Mass: 40818.477 Da / Num. of mol.: 5 Source method: isolated from a genetically manipulated source Source: (gene. exp.) Sus scrofa (pig) / Gene: ACTA1, ACTA / Production host: Sus scrofa (pig) / References: UniProt: P68137 #2: Protein | Mass: 11592.281 Da / Num. of mol.: 2 Source method: isolated from a genetically manipulated source Source: (gene. exp.) Sus scrofa (pig) / Production host: Sus scrofa (pig) #3: Chemical | ChemComp-ADP / #4: Chemical | ChemComp-MG / |
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-Experimental details
-Experiment
Experiment | Method: ELECTRON MICROSCOPY |
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EM experiment | Aggregation state: HELICAL ARRAY / 3D reconstruction method: helical reconstruction |
-Sample preparation
Component | Name: Native Cardiac Thin Filaments / Type: ORGANELLE OR CELLULAR COMPONENT / Details: Sample contains actin, tropomyosin, and troponin. / Entity ID: #1-#2 / Source: NATURAL |
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Molecular weight | Experimental value: NO |
Source (natural) | Organism: Sus scrofa (pig) |
Buffer solution | pH: 7 |
Specimen | Embedding applied: NO / Shadowing applied: NO / Staining applied: NO / Vitrification applied: YES |
Vitrification | Instrument: FEI VITROBOT MARK IV / Cryogen name: ETHANE / Humidity: 95 % |
-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: FIELD EMISSION GUN / Accelerating voltage: 300 kV / Illumination mode: FLOOD BEAM |
Electron lens | Mode: BRIGHT FIELD |
Image recording | Electron dose: 30 e/Å2 / Film or detector model: FEI FALCON II (4k x 4k) |
-Processing
EM software |
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CTF correction | Type: PHASE FLIPPING AND AMPLITUDE CORRECTION | |||||||||||||||||||||||||
Helical symmerty | Angular rotation/subunit: -166.7 ° / Axial rise/subunit: 27.4 Å / Axial symmetry: C1 | |||||||||||||||||||||||||
3D reconstruction | Resolution: 11 Å / Resolution method: FSC 0.5 CUT-OFF / Num. of particles: 3809 / Symmetry type: HELICAL | |||||||||||||||||||||||||
Atomic model building | Protocol: FLEXIBLE FIT / Space: REAL / Target criteria: Cross-correlation coefficient Details: Rigid fitting was done with Chimera and then DireX was used for flexible fitting. |