8VSX

NMR Structure of GCAP5 R22A


Experimental Data Snapshot

  • Method: SOLUTION NMR
  • Conformers Calculated: 500 
  • Conformers Submitted: 10 
  • Selection Criteria: structures with the least restraint violations 

wwPDB Validation   3D Report Full Report


This is version 1.1 of the entry. See complete history


Literature

NMR Structure of Retinal Guanylate Cyclase Activating Protein 5 (GCAP5) with R22A Mutation That Abolishes Dimerization and Enhances Cyclase Activation.

Cudia, D.L.Ahoulou, E.O.Bej, A.Janssen, A.N.Scholten, A.Koch, K.W.Ames, J.B.

(2024) Biochemistry 63: 1246-1256

  • DOI: https://doi.org/10.1021/acs.biochem.4c00046
  • Primary Citation of Related Structures:  
    8VSX

  • PubMed Abstract: 

    Guanylate cyclase activating protein-5 (GCAP5) in zebrafish photoreceptors promotes the activation of membrane receptor retinal guanylate cyclase (GC-E). Previously, we showed the R22A mutation in GCAP5 (GCAP5 R22A ) abolishes dimerization of GCAP5 and activates GC-E by more than 3-fold compared to that of wild-type GCAP5 (GCAP5 WT ). Here, we present ITC, NMR, and functional analysis of GCAP5 R22A to understand how R22A causes a decreased dimerization affinity and increased cyclase activation. ITC experiments reveal GCAP5 R22A binds a total of 3 Ca 2+ , including two sites in the nanomolar range followed by a single micromolar site. The two nanomolar sites in GCAP5 WT were not detected by ITC, suggesting that R22A may affect the binding of Ca 2+ to these sites. The NMR-derived structure of GCAP5 R22A is overall similar to that of GCAP5 WT (RMSD = 2.3 Å), except for local differences near R22A (Q19, W20, Y21, and K23) and an altered orientation of the C-terminal helix near the N-terminal myristate. GCAP5 R22A lacks an intermolecular salt bridge between R22 and D71 that may explain the weakened dimerization. We present a structural model of GCAP5 bound to GC-E in which the R22 side-chain contacts exposed hydrophobic residues in GC-E. Cyclase assays suggest that GC-E binds to GCAP5 R22A with ∼25% higher affinity compared to GCAP5 WT , consistent with more favorable hydrophobic contact by R22A that may help explain the increased cyclase activation.


  • Organizational Affiliation

    Department of Chemistry, University of California, Davis, Davis, California 95616, United States.


Macromolecules
Find similar proteins by:  (by identity cutoff)  |  3D Structure
Entity ID: 1
MoleculeChains Sequence LengthOrganismDetailsImage
Guanylyl cyclase-activating protein 1198Danio rerioMutation(s): 1 
Gene Names: GUCA1Eguca1e
UniProt
Find proteins for Q5MAC8 (Danio rerio)
Explore Q5MAC8 
Go to UniProtKB:  Q5MAC8
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupQ5MAC8
Sequence Annotations
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  • Reference Sequence
Experimental Data & Validation

Experimental Data

  • Method: SOLUTION NMR
  • Conformers Calculated: 500 
  • Conformers Submitted: 10 
  • Selection Criteria: structures with the least restraint violations 

Structure Validation

View Full Validation Report



Entry History & Funding Information

Deposition Data


Funding OrganizationLocationGrant Number
National Institutes of Health/National Eye Institute (NIH/NEI)United StatesR01 EY012347

Revision History  (Full details and data files)

  • Version 1.0: 2024-05-08
    Type: Initial release
  • Version 1.1: 2024-06-05
    Changes: Database references