1I84

CRYO-EM STRUCTURE OF THE HEAVY MEROMYOSIN SUBFRAGMENT OF CHICKEN GIZZARD SMOOTH MUSCLE MYOSIN WITH REGULATORY LIGHT CHAIN IN THE DEPHOSPHORYLATED STATE. ONLY C ALPHAS PROVIDED FOR REGULATORY LIGHT CHAIN. ONLY BACKBONE ATOMS PROVIDED FOR S2 FRAGMENT.


Experimental Data Snapshot

  • Method: ELECTRON CRYSTALLOGRAPHY
  • Resolution: 20.0 Å

wwPDB Validation   3D Report Full Report


This is version 1.3 of the entry. See complete history


Literature

Three-dimensional image reconstruction of dephosphorylated smooth muscle heavy meromyosin reveals asymmetry in the interaction between myosin heads and placement of subfragment 2.

Wendt, T.Taylor, D.Trybus, K.M.Taylor, K.

(2001) Proc Natl Acad Sci U S A 98: 4361-4366

  • DOI: https://doi.org/10.1073/pnas.071051098
  • Primary Citation of Related Structures:  
    1I84

  • PubMed Abstract: 

    Regulation of the actin-activated ATPase of smooth muscle myosin II is known to involve an interaction between the two heads that is controlled by phosphorylation of the regulatory light chain. However, the three-dimensional structure of this inactivated form has been unknown. We have used a lipid monolayer to obtain two-dimensional crystalline arrays of the unphosphorylated inactive form of smooth muscle heavy meromyosin suitable for structural studies by electron cryomicroscopy of unstained, frozen-hydrated specimens. The three-dimensional structure reveals an asymmetric interaction between the two myosin heads. The ATPase activity of one head is sterically "blocked" because part of its actin-binding interface is positioned onto the converter domain of the second head. ATPase activity of the second head, which can bind actin, appears to be inhibited through stabilization of converter domain movements needed to release phosphate and achieve strong actin binding. When the subfragment 2 domain of heavy meromyosin is oriented as it would be in an actomyosin filament lattice, the position of the heads is very different from that needed to bind actin, suggesting an additional contribution to ATPase inhibition in situ.


  • Organizational Affiliation

    Institute of Molecular Biophysics, Florida State University, Tallahassee, FL 32306, USA.


Macromolecules
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Entity ID: 1
MoleculeChains Sequence LengthOrganismDetailsImage
SMOOTH MUSCLE MYOSIN HEAVY CHAINA [auth S],
D [auth V]
1,184Gallus gallusMutation(s): 0 
UniProt
Find proteins for P10587 (Gallus gallus)
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Go to UniProtKB:  P10587
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UniProt GroupP10587
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  • Reference Sequence
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Entity ID: 2
MoleculeChains Sequence LengthOrganismDetailsImage
SMOOTH MUSCLE MYOSIN ESSENTIAL LIGHT CHAINB [auth T],
E [auth W]
150Gallus gallusMutation(s): 0 
UniProt
Find proteins for P02607 (Gallus gallus)
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UniProt GroupP02607
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Entity ID: 3
MoleculeChains Sequence LengthOrganismDetailsImage
SMOOTH MUSCLE MYOSIN REGULATORY LIGHT CHAINC [auth U],
F [auth Z]
166Gallus gallusMutation(s): 0 
UniProt
Find proteins for P02609 (Gallus gallus)
Explore P02609 
Go to UniProtKB:  P02609
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UniProt GroupP02609
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  • Reference Sequence
Small Molecules
Modified Residues  1 Unique
IDChains TypeFormula2D DiagramParent
MLY
Query on MLY
A [auth S],
D [auth V]
L-PEPTIDE LINKINGC8 H18 N2 O2LYS
Experimental Data & Validation

Experimental Data

  • Method: ELECTRON CRYSTALLOGRAPHY
  • Resolution: 20.0 Å
  • Space Group: P 1 1 2
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 133α = 90
b = 304β = 90
c = 200γ = 91.5

Structure Validation

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Entry History 

Deposition Data

Revision History  (Full details and data files)

  • Version 1.0: 2001-03-28
    Type: Initial release
  • Version 1.1: 2008-04-27
    Changes: Version format compliance
  • Version 1.2: 2011-07-13
    Changes: Version format compliance
  • Version 1.3: 2022-12-21
    Changes: Data collection, Database references, Derived calculations