3LPW

Crystal structure of the FnIII-tandem A77-A78 from the A-band of titin


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.65 Å
  • R-Value Free: 0.208 
  • R-Value Work: 0.179 

wwPDB Validation 3D Report Full Report


This is version 1.1 of the entry. See complete history

Literature

The structure of the FnIII Tandem A77-A78 points to a periodically conserved architecture in the myosin-binding region of titin

Bucher, R.M.Svergun, D.I.Muhle-Goll, C.Mayans, O.

(2010) J.Mol.Biol. 401: 843-853

  • DOI: 10.1016/j.jmb.2010.06.011

  • PubMed Abstract: 
  • Titin is a large intrasarcomeric protein that, among its many roles in muscle, is thought to modulate the in vivo assembly of the myosin motor filament. This is achieved through the molecular template properties of its A-band region, which is compose ...

    Titin is a large intrasarcomeric protein that, among its many roles in muscle, is thought to modulate the in vivo assembly of the myosin motor filament. This is achieved through the molecular template properties of its A-band region, which is composed of fibronectin type III (FnIII) and immunoglobulin (Ig) domains organized into characteristic 7-domain (D-zone) and 11-domain (C-zone) superrepeats. Currently, there is little knowledge on the structural details of this region of titin. Here we report the conformational characterization of three FnIII tandems, A77-A78, A80-A82, and A84-A86, which are components of the representative fourth C-zone superrepeat. The structure of A77-A78 has been elucidated by X-ray crystallography to 1.65 A resolution, while low-resolution models of A80-A82 and A84-A86 have been calculated using small-angle X-ray scattering. A77-A78 adopts an extended "up-down" domain arrangement, where domains are connected by a hydrophilic three-residue linker sequence. The linker is embedded in a rich network of polar contacts at the domain interface that results in a stiff molecular conformation. The models of A80-A82 and A84-A86, which contain hydrophobic six-residue-long interdomain linkers, equally showed elongated molecular shapes, but with slightly coiled or zigzagged conformations. Small-angle X-ray scattering data further suggested that the long linkers do not result in a noticeable increase in molecular flexibility but lead to semibent domain arrangements. Our findings indicate that the structural characteristics of FnIII tandems from A-band titin contrast markedly with those of poly-Ig tandems from the elastic I-band, which exhibit domain interfaces depleted of interactions and compliant conformations. Furthermore, the analysis of sequence conservation in FnIII domains from A-band titin points to the existence of conformationally defined interfaces at specific superrepeat positions, possibly leading to a periodic and locally ordered architecture supporting the molecular scaffold properties of this region of titin.


    Organizational Affiliation

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




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
A77-A78 domain from Titin
A, B
197Homo sapiensMutation(s): 0 
Gene Names: TTN
EC: 2.7.11.1
Find proteins for Q8WZ42 (Homo sapiens)
Go to Gene View: TTN
Go to UniProtKB:  Q8WZ42
Small Molecules
Ligands 2 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
MRD
Query on MRD

Download SDF File 
Download CCD File 
A
(4R)-2-METHYLPENTANE-2,4-DIOL
C6 H14 O2
SVTBMSDMJJWYQN-RXMQYKEDSA-N
 Ligand Interaction
MPD
Query on MPD

Download SDF File 
Download CCD File 
A, B
(4S)-2-METHYL-2,4-PENTANEDIOL
C6 H14 O2
SVTBMSDMJJWYQN-YFKPBYRVSA-N
 Ligand Interaction
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.65 Å
  • R-Value Free: 0.208 
  • R-Value Work: 0.179 
  • Space Group: C 2 2 21
Unit Cell:
Length (Å)Angle (°)
a = 115.900α = 90.00
b = 163.200β = 90.00
c = 65.200γ = 90.00
Software Package:
Software NamePurpose
PHASERphasing
MAR345dtbdata collection
PHENIXrefinement
XDSdata reduction
XSCALEdata scaling

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2010-09-08
    Type: Initial release
  • Version 1.1: 2011-07-13
    Type: Version format compliance