3JBH

TWO HEAVY MEROMYOSIN INTERACTING-HEADS MOTIFS FLEXIBLE DOCKED INTO TARANTULA THICK FILAMENT 3D-MAP ALLOWS IN DEPTH STUDY OF INTRA- AND INTERMOLECULAR INTERACTIONS


Experimental Data Snapshot

  • Method: ELECTRON MICROSCOPY
  • Resolution: 20.0 Å
  • Aggregation State: FILAMENT 
  • Reconstruction Method: HELICAL 

wwPDB Validation 3D Report Full Report


This is version 1.2 of the entry. See complete history


Literature

Conserved Intramolecular Interactions Maintain Myosin Interacting-Heads Motifs Explaining Tarantula Muscle Super-Relaxed State Structural Basis.

Alamo, L.Qi, D.Wriggers, W.Pinto, A.Zhu, J.Bilbao, A.Gillilan, R.E.Hu, S.Padron, R.

(2016) J Mol Biol 428: 1142-1164

  • DOI: 10.1016/j.jmb.2016.01.027
  • Primary Citation of Related Structures:  
    3JBH

  • PubMed Abstract: 
  • Tarantula striated muscle is an outstanding system for understanding the molecular organization of myosin filaments. Three-dimensional reconstruction based on cryo-electron microscopy images and single-particle image processing revealed that, in a re ...

    Tarantula striated muscle is an outstanding system for understanding the molecular organization of myosin filaments. Three-dimensional reconstruction based on cryo-electron microscopy images and single-particle image processing revealed that, in a relaxed state, myosin molecules undergo intramolecular head-head interactions, explaining why head activity switches off. The filament model obtained by rigidly docking a chicken smooth muscle myosin structure to the reconstruction was improved by flexibly fitting an atomic model built by mixing structures from different species to a tilt-corrected 2-nm three-dimensional map of frozen-hydrated tarantula thick filament. We used heavy and light chain sequences from tarantula myosin to build a single-species homology model of two heavy meromyosin interacting-heads motifs (IHMs). The flexibly fitted model includes previously missing loops and shows five intramolecular and five intermolecular interactions that keep the IHM in a compact off structure, forming four helical tracks of IHMs around the backbone. The residues involved in these interactions are oppositely charged, and their sequence conservation suggests that IHM is present across animal species. The new model, PDB 3JBH, explains the structural origin of the ATP turnover rates detected in relaxed tarantula muscle by ascribing the very slow rate to docked unphosphorylated heads, the slow rate to phosphorylated docked heads, and the fast rate to phosphorylated undocked heads. The conservation of intramolecular interactions across animal species and the presence of IHM in bilaterians suggest that a super-relaxed state should be maintained, as it plays a role in saving ATP in skeletal, cardiac, and smooth muscles.


    Related Citations: 
    • Three-dimensional reconstruction of tarantula myosin filaments suggests how phosphorylation may regulate myosin activity.
      Alamo, L., Wriggers, W., Pinto, A., Bartoli, F., Salazar, L., Zhao, F.Q., Craig, R., Padron, R.
      (2008) J Mol Biol 384: 780
    • Analysis of tarantula skeletal muscle protein sequences and identification of transcriptional isoforms.
      Zhu, J., Sun, Y., Zhao, F.Q., Yu, J., Craig, R., Hu, S.
      (2009) BMC Genomics 10: 117

    Organizational Affiliation

    Centro de BiologĂ­a Estructural, Instituto Venezolano de Investigaciones CientĂ­ficas, Apartado 20632, Caracas 1020A, Venezuela. Electronic address: raul.padron@gmail.com.



Macromolecules
Find similar proteins by:  (by identity cutoff)  |  Structure
Entity ID: 2
MoleculeChainsSequence LengthOrganismDetailsImage
MYOSIN 2 ESSENTIAL LIGHT CHAIN STRIATED MUSCLEC, D, I, J156AphonopelmaMutation(s): 0 
Find proteins for A0A140UGH4 (Aphonopelma)
Explore A0A140UGH4 
Go to UniProtKB:  A0A140UGH4
Protein Feature View
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  • Reference Sequence
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Entity ID: 1
MoleculeChainsSequence LengthOrganismDetailsImage
MYOSIN 2 HEAVY CHAIN STRIATED MUSCLEA, B, G, H1953AphonopelmaMutation(s): 0 
Find proteins for A0A140UGH3 (Aphonopelma)
Explore A0A140UGH3 
Go to UniProtKB:  A0A140UGH3
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  • Reference Sequence
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Entity ID: 3
MoleculeChainsSequence LengthOrganismDetailsImage
MYOSIN 2 REGULATORY LIGHT CHAIN STRIATED MUSCLEE, F, K, L196AphonopelmaMutation(s): 0 
Find proteins for A0A140UGH5 (Aphonopelma)
Explore A0A140UGH5 
Go to UniProtKB:  A0A140UGH5
Protein Feature View
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  • Reference Sequence
Experimental Data & Validation

Experimental Data

  • Method: ELECTRON MICROSCOPY
  • Resolution: 20.0 Å
  • Aggregation State: FILAMENT 
  • Reconstruction Method: HELICAL 

Structure Validation

View Full Validation Report



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2016-03-09
    Type: Initial release
  • Version 1.1: 2016-12-14
    Changes: Database references
  • Version 1.2: 2018-07-18
    Changes: Author supporting evidence, Data collection