3B43

I-band fragment I65-I70 from titin


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 3.3 Å
  • R-Value Free: 0.267 
  • R-Value Work: 0.220 

wwPDB Validation 3D Report Full Report


This is version 1.1 of the entry. See complete history

Literature

A regular pattern of Ig super-motifs defines segmental flexibility as the elastic mechanism of the titin chain

von Castelmur, E.Marino, M.Svergun, D.I.Kreplak, L.Ucurum-Fotiadis, Z.Konarev, P.V.Urzhumtsev, A.Labeit, D.Labeit, S.Mayans, O.

(2008) Proc.Natl.Acad.Sci.Usa 105: 1186-1191

  • DOI: 10.1073/pnas.0707163105
  • Primary Citation of Related Structures:  

  • PubMed Abstract: 
  • Myofibril elasticity, critical to muscle function, is dictated by the intrasarcomeric filament titin, which acts as a molecular spring. To date, the molecular events underlying the mechanics of the folded titin chain remain largely unknown. We have e ...

    Myofibril elasticity, critical to muscle function, is dictated by the intrasarcomeric filament titin, which acts as a molecular spring. To date, the molecular events underlying the mechanics of the folded titin chain remain largely unknown. We have elucidated the crystal structure of the 6-Ig fragment I65-I70 from the elastic I-band fraction of titin and validated its conformation in solution using small angle x-ray scattering. The long-range properties of the chain have been visualized by electron microscopy on a 19-Ig fragment and modeled for the full skeletal tandem. Results show that conserved Ig-Ig transition motifs generate high-order in the structure of the filament, where conformationally stiff segments interspersed with pliant hinges form a regular pattern of dynamic super-motifs leading to segmental flexibility in the chain. Pliant hinges support molecular shape rearrangements that dominate chain behavior at moderate stretch, whereas stiffer segments predictably oppose high stretch forces upon full chain extension. There, librational entropy can be expected to act as an energy barrier to prevent Ig unfolding while, instead, triggering the unraveling of flanking springs formed by proline, glutamate, valine, and lysine (PEVK) sequences. We propose a mechanistic model based on freely jointed rigid segments that rationalizes the response to stretch of titin Ig-tandems according to molecular features.


    Related Citations: 
    • Poly-Ig tandems from I-band titin share extended domain arrangements irrespective of the distinct features of their modular constituents
      Marino, M.,Svergun, D.I.,Kreplak, L.,Konarev, P.V.,Maco, B.,Labeit, D.,Mayans, O.
      (2005) J.Muscle Res.Cell.Motil. 26: 355


    Organizational Affiliation

    Division of Structural Biology, Biozentrum, University of Basel, Klingelbergstrasse 70, CH-4056 Basel, Switzerland.




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
Titin
A
570Oryctolagus cuniculusMutation(s): 0 
EC: 2.7.11.1
Find proteins for D0VWS0 (Oryctolagus cuniculus)
Go to UniProtKB:  D0VWS0
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 3.3 Å
  • R-Value Free: 0.267 
  • R-Value Work: 0.220 
  • Space Group: P 65 2 2
Unit Cell:
Length (Å)Angle (°)
a = 141.430α = 90.00
b = 141.430β = 90.00
c = 166.010γ = 120.00
Software Package:
Software NamePurpose
XDSdata reduction
PDB_EXTRACTdata extraction
XSCALEdata scaling
SHARPphasing
PHENIXrefinement
XSCALEdata processing

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2008-01-22
    Type: Initial release
  • Version 1.1: 2011-07-13
    Type: Derived calculations, Version format compliance