2K3S

HADDOCK-derived structure of the CH-domain of the smoothelin-like 1 complexed with the C-domain of apocalmodulin


Experimental Data Snapshot

  • Method: SOLUTION NMR
  • Conformers Calculated: 1000 
  • Conformers Submitted: 15 
  • Selection Criteria: structures with the lowest energy 

wwPDB Validation 3D Report Full Report


This is version 1.1 of the entry. See complete history

Literature

Solution structure of the calponin homology (CH) domain from the smoothelin-like 1 protein: a unique apocalmodulin-binding mode and the possible role of the C-terminal type-2 CH-domain in smooth muscle relaxation.

Ishida, H.Borman, M.A.Ostrander, J.Vogel, H.J.MacDonald, J.A.

(2008) J.Biol.Chem. 283: 20569-20578

  • DOI: 10.1074/jbc.M800627200
  • Primary Citation of Related Structures:  

  • PubMed Abstract: 
  • The SMTNL1 protein contains a single type-2 calponin homology (CH) domain at its C terminus that shares sequence identity with the smoothelin family of smooth muscle-specific proteins. In contrast to the smoothelins, SMTNL1 does not associate with F- ...

    The SMTNL1 protein contains a single type-2 calponin homology (CH) domain at its C terminus that shares sequence identity with the smoothelin family of smooth muscle-specific proteins. In contrast to the smoothelins, SMTNL1 does not associate with F-actin in vitro, and its specific role in smooth muscle remains unclear. In addition, the biological function of the C-terminal CH-domains found in the smoothelin proteins is also poorly understood. In this work, we have therefore determined the solution structure of the CH-domain of mouse SMTNL1 (SMTNL1-CH; residues 346-459). The secondary structure and the overall fold for the C-terminal type-2 CH-domain is very similar to that of other CH-domains. However, two clusters of basic residues form a unique surface structure that is characteristic of SMTNL1-CH. Moreover, the protein has an extended C-terminal alpha-helix, which contains a calmodulin (CaM)-binding IQ-motif, that is also a distinct feature of the smoothelins. We have characterized the binding of apo-CaM to SMTNL1-CH through its IQ-motif by isothermal titration calorimetry and NMR chemical shift perturbation studies. In addition, we have used the HADDOCK protein-protein docking approach to construct a model for the complex of apo-CaM and SMTNL1-CH. The model revealed a close interaction of SMTNL1-CH with the two Ca(2+) binding loop regions of the C-terminal domain of apo-CaM; this mode of apo-CaM binding is distinct from previously reported interactions of apo-CaM with IQ-motifs. Finally, we comment on the putative role of the CH-domain in the biological function of SMTNL1.


    Organizational Affiliation

    Department of Biological Sciences, University of Calgary, Calgary, Alberta, Canada.




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
Smoothelin-like protein 1
A
119Mus musculusMutation(s): 0 
Gene Names: Smtnl1
Find proteins for Q99LM3 (Mus musculus)
Go to UniProtKB:  Q99LM3
Entity ID: 2
MoleculeChainsSequence LengthOrganismDetails
Calmodulin
B
67Xenopus laevisMutation(s): 0 
Gene Names: calm2-b
Find proteins for P0DP35 (Xenopus laevis)
Go to UniProtKB:  P0DP35
Experimental Data & Validation

Experimental Data

  • Method: SOLUTION NMR
  • Conformers Calculated: 1000 
  • Conformers Submitted: 15 
  • Selection Criteria: structures with the lowest energy 
  • Olderado: 2K3S Olderado

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2008-05-27
    Type: Initial release
  • Version 1.1: 2011-07-13
    Type: Version format compliance