1C1G | pdb_00001c1g

CRYSTAL STRUCTURE OF TROPOMYOSIN AT 7 ANGSTROMS RESOLUTION IN THE SPERMINE-INDUCED CRYSTAL FORM

• PDB DOI: https://doi.org/10.2210/pdb1C1G/pdb

• Classification: CONTRACTILE PROTEIN
• Organism(s): Sus scrofa
• Mutation(s): No 


• Deposited: 1999-07-22 Released: 2000-02-11 
• Deposition Author(s): Whitby, F.G., Phillips Jr., G.N.

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Experimental Data Snapshot

• Method: X-RAY DIFFRACTION
• Resolution: 7.00 Å
• R-Value Work: 
  0.404 (Depositor), 0.450 (DCC) 

Literature

Crystal structure of tropomyosin at 7 Angstroms resolution.

Whitby, F.G., Phillips Jr., G.N.

(2000) Proteins 38: 49-59

• PubMed: 10651038 
• Primary Citation Related Structures: 
  1C1G


• PubMed Abstract: 
  

  Tropomyosin is a 400A-long coiled coil that polymerizes to form a continuous filament that associates with actin in muscle and numerous non-muscle cells. Tropomyosin and troponin together form a calcium-sensitive switch that is responsible for thin-filament regulation of striated muscle. Subtle structural features of the molecule, including non-canonical aspects of its coiled-coil motif, undoubtedly influence its association with f-actin and its role in thin filament regulation. Previously, careful inspection of native diffraction intensities was sufficient to construct a model of tropomyosin at 9A resolution in a spermine-induced crystal form that diffracts anisotropically to 4A resolution. Single isomorphous replacement (SIR) phasing has now provided an empirical determination of the structure at 7A resolution. A novel method of heavy-atom analysis was used to overcome difficulties in interpretation of extremely anisotropic diffraction. The packing arrangement of the molecules in the crystal, and important aspects of the tropomyosin geometry such as non-uniformities of the pitch and variable bending and radius of the coiled coil are evident.

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Organizational Affiliation: 
• Department of Biochemistry and Cell Biology, Rice University, Houston, Texas 77005, USA.

Biological Assembly 1  

Global Symmetry: Asymmetric - C1 
Global Stoichiometry: Homo 2-mer - A2 

Biological assembly 1 assigned by authors and generated by PISA (software)

Biological Assembly 2  

Global Symmetry: Asymmetric - C1 
Global Stoichiometry: Homo 2-mer - A2 

Biological assembly 2 assigned by authors and generated by PISA (software)

Macromolecule Content 

• Total Structure Weight: 131.14 kDa 
• Atom Count: 9,160 
• Modeled Residue Count: 1,136 
• Deposited Residue Count: 1,136 
• Unique protein chains: 1

Macromolecules

Entity ID: 1
Molecule	Chains	Sequence Length	Organism	Details	Image
TROPOMYOSIN	A, B, C, D	284	Sus scrofa	Mutation(s): 0
UniProt
Find proteins for P42639 (Sus scrofa) Explore P42639  Go to UniProtKB:  P42639

Experimental Data & Validation

Experimental Data

• Method: X-RAY DIFFRACTION
• Resolution: 7.00 Å
• R-Value Work:  0.404 (Depositor), 0.450 (DCC) 

Space Group: C 1 2 1

Unit Cell:

Length ( Å )	Angle ( ˚ )
a = 259.738	α = 90
b = 55.3	β = 97.415
c = 136.259	γ = 90

Software Package:

Software Name	Purpose
XTALVIEW	refinement
X-PLOR	refinement
XDS	data reduction
XDS	data scaling

Structure Validation

Entry History 

Deposition Data

• Released Date: 2000-02-11 
Deposition Author(s): Whitby, F.G., Phillips Jr., G.N.

Revision History  

• Version 1.0: 2000-02-11
  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: 2018-01-31
  Changes: Experimental preparation
• Version 1.4: 2024-02-07
  Changes: Data collection, Database references