Crystal structure of domains A168-A170 from titin

Experimental Data Snapshot

  • Resolution: 2.90 Å
  • R-Value Free: 0.274 
  • R-Value Work: 0.219 
  • R-Value Observed: 0.219 

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Molecular determinants for the recruitment of the ubiquitin-ligase MuRF-1 onto M-line titin.

Mrosek, M.Labeit, D.Witt, S.Heerklotz, H.von Castelmur, E.Labeit, S.Mayans, O.

(2007) FASEB J 21: 1383-1392

  • DOI: https://doi.org/10.1096/fj.06-7644com
  • Primary Citation of Related Structures:  

  • PubMed Abstract: 

    Titin forms an intrasarcomeric filament system in vertebrate striated muscle, which has elastic and signaling properties and is thereby central to mechanotransduction. Near its C-terminus and directly preceding a kinase domain, titin contains a conserved pattern of Ig and FnIII modules (Ig(A168)-Ig(A169)-FnIII(A170), hereby A168-A170) that recruits the E3 ubiquitin-ligase MuRF-1 to the filament. This interaction is thought to regulate myofibril turnover and the trophic state of muscle. We have elucidated the crystal structure of A168-A170, characterized MuRF-1 variants by circular dichroism (CD) and SEC-MALS, and studied the interaction of both components by isothermal calorimetry, SPOTS blots, and pull-down assays. This has led to the identification of the molecular determinants of the binding. A168-A170 shows an extended, rigid architecture, which is characterized by a shallow surface groove that spans its full length and a distinct loop protrusion in its middle point. In MuRF-1, a C-terminal helical domain is sufficient to bind A168-A170 with high affinity. This helical region predictably docks into the surface groove of A168-A170. Furthermore, pull-down assays demonstrate that the loop protrusion in A168-A170 is a key mediator of MuRF-1 recognition. Our findings indicate that this region of titin could serve as a target to attempt therapeutic inhibition of MuRF-1-mediated muscle turnover, where binding of small molecules to its distinctive structural features could block MuRF-1 access.

  • Organizational Affiliation

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

Find similar proteins by:  (by identity cutoff)  |  3D Structure
Entity ID: 1
MoleculeChains Sequence LengthOrganismDetailsImage
A, B
305Homo sapiensMutation(s): 0 
Gene Names: TTN
UniProt & NIH Common Fund Data Resources
Find proteins for Q8WZ42 (Homo sapiens)
Explore Q8WZ42 
Go to UniProtKB:  Q8WZ42
GTEx:  ENSG00000155657 
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupQ8WZ42
Sequence Annotations
  • Reference Sequence
Experimental Data & Validation

Experimental Data

  • Resolution: 2.90 Å
  • R-Value Free: 0.274 
  • R-Value Work: 0.219 
  • R-Value Observed: 0.219 
  • Space Group: P 31 2 1
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 125.89α = 90
b = 125.89β = 90
c = 134.1γ = 120
Software Package:
Software NamePurpose
ADSCdata collection
XDSdata reduction
XSCALEdata scaling

Structure Validation

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Entry History 

Deposition Data

Revision History  (Full details and data files)

  • Version 1.0: 2007-02-13
    Type: Initial release
  • Version 1.1: 2008-05-01
    Changes: Version format compliance
  • Version 1.2: 2011-07-13
    Changes: Version format compliance
  • Version 1.3: 2023-12-27
    Changes: Data collection, Database references