Structure of the human beta-myosin S2 fragment

Experimental Data Snapshot

  • Resolution: 2.50 Å
  • R-Value Free: 0.349 
  • R-Value Work: 0.273 
  • R-Value Observed: 0.277 

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Crystal structures of human cardiac {beta}-myosin II S2-{Delta} provide insight into the functional role of the S2 subfragment

Blankenfeldt, W.Thoma, N.H.Wray, J.S.Gautel, M.Schlichting, I.

(2006) Proc Natl Acad Sci U S A 103: 17713-17717

  • DOI: https://doi.org/10.1073/pnas.0606741103
  • Primary Citation of Related Structures:  
    2FXM, 2FXO

  • PubMed Abstract: 

    Myosin II is the major component of the muscle thick filament. It consists of two N-terminal S1 subfragments ("heads") connected to a long dimeric coiled-coil rod. The rod is in itself twofold symmetric, but in the filament, the two heads point away from the filament surface and are therefore not equivalent. This breaking of symmetry requires the initial section of the rod, subfragment 2 (S2), to be relatively flexible. S2 is an important functional element, involved in various mechanisms by which the activity of smooth and striated muscle is regulated. We have determined crystal structures of the 126 N-terminal residues of S2 from human cardiac beta-myosin II (S2-Delta), of both WT and the disease-associated E924K mutant. S2-Delta is a straight parallel dimeric coiled coil, but the N terminus of one chain is disordered in WT-S2-Delta due to crystal contacts, indicative of unstable local structure. Bulky noncanonical side chains pack into a/d positions of S2-Delta's N terminus, leading to defined local asymmetry and axial stagger, which could induce nonequivalence of the S1 subfragments. Additionally, S2 possesses a conserved charge distribution with three prominent rings of negative potential within S2-Delta, the first of which may provide a binding interface for the "blocked head" of smooth muscle myosin in the OFF state. The observation that many disease-associated mutations affect the second negatively charged ring further suggests that charge interactions play an important role in regulation of cardiac muscle activity through myosin-binding protein C.

  • Organizational Affiliation

    Max Planck Institute of Molecular Physiology, Department of Physical Biochemistry, 44227 Dortmund, Germany. wulf.blankenfeldt@mpi-dortmund.mpg.de

Find similar proteins by:  (by identity cutoff)  |  3D Structure
Entity ID: 1
MoleculeChains Sequence LengthOrganismDetailsImage
Myosin heavy chain, cardiac muscle beta isoform
A, B, C, D
129Homo sapiensMutation(s): 1 
Gene Names: HSBMHC
UniProt & NIH Common Fund Data Resources
Find proteins for P12883 (Homo sapiens)
Explore P12883 
Go to UniProtKB:  P12883
PHAROS:  P12883
GTEx:  ENSG00000092054 
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupP12883
Sequence Annotations
  • Reference Sequence
Experimental Data & Validation

Experimental Data

  • Resolution: 2.50 Å
  • R-Value Free: 0.349 
  • R-Value Work: 0.273 
  • R-Value Observed: 0.277 
  • Space Group: P 1
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 40.157α = 91.11
b = 41.867β = 92.73
c = 97.795γ = 107.18
Software Package:
Software NamePurpose
XDSdata scaling
XDSdata reduction
MOLEMAN2model building

Structure Validation

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Entry History 

Deposition Data

Revision History  (Full details and data files)

  • Version 1.0: 2006-11-21
    Type: Initial release
  • Version 1.1: 2008-05-01
    Changes: Version format compliance
  • Version 1.2: 2011-07-13
    Changes: Advisory, Version format compliance
  • Version 1.3: 2017-10-18
    Changes: Advisory, Refinement description
  • Version 1.4: 2021-11-10
    Changes: Advisory, Database references
  • Version 1.5: 2023-10-25
    Changes: Data collection, Refinement description