4E34

Crystal structure of CFTR Associated Ligand (CAL) PDZ domain bound to iCAL36 (ANSRWPTSII) peptide


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.40 Å
  • R-Value Free: 0.197 
  • R-Value Work: 0.173 
  • R-Value Observed: 0.174 

wwPDB Validation   3D Report Full Report


This is version 1.2 of the entry. See complete history


Literature

Stereochemical Determinants of C-terminal Specificity in PDZ Peptide-binding Domains: A NOVEL CONTRIBUTION OF THE CARBOXYLATE-BINDING LOOP.

Amacher, J.F.Cushing, P.R.Bahl, C.D.Beck, T.Madden, D.R.

(2013) J Biol Chem 288: 5114-5126

  • DOI: https://doi.org/10.1074/jbc.M112.401588
  • Primary Citation of Related Structures:  
    4E34, 4E35, 4E3B

  • PubMed Abstract: 

    PDZ (PSD-95/Dlg/ZO-1) binding domains often serve as cellular traffic engineers, controlling the localization and activity of a wide variety of binding partners. As a result, they play important roles in both physiological and pathological processes. However, PDZ binding specificities overlap, allowing multiple PDZ proteins to mediate distinct effects on shared binding partners. For example, several PDZ domains bind the cystic fibrosis (CF) transmembrane conductance regulator (CFTR), an epithelial ion channel mutated in CF. Among these binding partners, the CFTR-associated ligand (CAL) facilitates post-maturational degradation of the channel and is thus a potential therapeutic target. Using iterative optimization, we previously developed a selective CAL inhibitor peptide (iCAL36). Here, we investigate the stereochemical basis of iCAL36 specificity. The crystal structure of iCAL36 in complex with the CAL PDZ domain reveals stereochemical interactions distributed along the peptide-binding cleft, despite the apparent degeneracy of the CAL binding motif. A critical selectivity determinant that distinguishes CAL from other CFTR-binding PDZ domains is the accommodation of an isoleucine residue at the C-terminal position (P(0)), a characteristic shared with the Tax-interacting protein-1. Comparison of the structures of these two PDZ domains in complex with ligands containing P(0) Leu or Ile residues reveals two distinct modes of accommodation for β-branched C-terminal side chains. Access to each mode is controlled by distinct residues in the carboxylate-binding loop. These studies provide new insights into the primary sequence determinants of binding motifs, which in turn control the scope and evolution of PDZ interactomes.


  • Organizational Affiliation

    Department of Biochemistry, Geisel School of Medicine at Dartmouth, Hanover, New Hampshire 03755, USA.


Macromolecules
Find similar proteins by:  (by identity cutoff)  |  3D Structure
Entity ID: 1
MoleculeChains Sequence LengthOrganismDetailsImage
Golgi-associated PDZ and coiled-coil motif-containing protein
A, B
87Homo sapiensMutation(s): 0 
Gene Names: GOPCCALFIG
UniProt & NIH Common Fund Data Resources
Find proteins for Q9HD26 (Homo sapiens)
Explore Q9HD26 
Go to UniProtKB:  Q9HD26
PHAROS:  Q9HD26
GTEx:  ENSG00000047932 
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupQ9HD26
Sequence Annotations
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  • Reference Sequence

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Entity ID: 2
MoleculeChains Sequence LengthOrganismDetailsImage
decameric peptide, iCAL36
C, D
10N/AMutation(s): 0 
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
Sequence Annotations
Expand
  • Reference Sequence
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 1.40 Å
  • R-Value Free: 0.197 
  • R-Value Work: 0.173 
  • R-Value Observed: 0.174 
  • Space Group: P 21 21 21
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 35.878α = 90
b = 47.709β = 90
c = 97.301γ = 90
Software Package:
Software NamePurpose
HKL-2000data collection
SHELXmodel building
PHENIXrefinement
XDSdata reduction
XPREPdata reduction
SHELXphasing

Structure Validation

View Full Validation Report



Entry History 

Deposition Data

Revision History  (Full details and data files)

  • Version 1.0: 2012-12-26
    Type: Initial release
  • Version 1.1: 2013-03-06
    Changes: Database references
  • Version 1.2: 2024-02-28
    Changes: Data collection, Database references, Derived calculations