Regulator of G protein signaling (RGS) 17 in complex with Ca2+

Experimental Data Snapshot

  • Resolution: 1.53 Å
  • R-Value Free: 0.225 
  • R-Value Work: 0.203 
  • R-Value Observed: 0.204 

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This is version 1.2 of the entry. See complete history


High-resolution structure of RGS17 suggests a role for Ca2+in promoting the GTPase-activating protein activity by RZ subfamily members.

Sieng, M.Hayes, M.P.O'Brien, J.B.Andrew Fowler, C.Houtman, J.C.Roman, D.L.Lyon, A.M.

(2019) J Biol Chem 294: 8148-8160

  • DOI: https://doi.org/10.1074/jbc.RA118.006059
  • Primary Citation of Related Structures:  

  • PubMed Abstract: 

    Regulator of G protein signaling (RGS) proteins are negative regulators of G protein-coupled receptor (GPCR) signaling through their ability to act as GTPase-activating proteins (GAPs) for activated Gα subunits. Members of the RZ subfamily of RGS proteins bind to activated Gα o , Gα z , and Gα i1-3 proteins in the nervous system and thereby inhibit downstream pathways, including those involved in Ca 2+ -dependent signaling. In contrast to other RGS proteins, little is known about RZ subfamily structure and regulation. Herein, we present the 1.5-Å crystal structure of RGS17, the most complete and highest-resolution structure of an RZ subfamily member to date. RGS17 cocrystallized with Ca 2+ bound to conserved positions on the predicted Gα-binding surface of the protein. Using NMR chemical shift perturbations, we confirmed that Ca 2+ binds in solution to the same site. Furthermore, RGS17 had greater than 55-fold higher affinity for Ca 2+ than for Mg 2+ Finally, we found that Ca 2+ promotes interactions between RGS17 and activated Gα and decreases the K m for GTP hydrolysis, potentially by altering the binding mechanism between these proteins. Taken together, these findings suggest that Ca 2+ positively regulates RGS17, which may represent a general mechanism by which increased Ca 2+ concentration promotes the GAP activity of the RZ subfamily, leading to RZ-mediated inhibition of Ca 2+ signaling.

  • Organizational Affiliation

    Department of Chemistry, Purdue University, West Lafayette, Indiana 47907.

Find similar proteins by:  (by identity cutoff)  |  3D Structure
Entity ID: 1
MoleculeChains Sequence LengthOrganismDetailsImage
Regulator of G-protein signaling 17A [auth X],
B [auth A]
137Homo sapiensMutation(s): 0 
Gene Names: RGS17RGSZ2
UniProt & NIH Common Fund Data Resources
Find proteins for Q9UGC6 (Homo sapiens)
Explore Q9UGC6 
Go to UniProtKB:  Q9UGC6
GTEx:  ENSG00000091844 
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupQ9UGC6
Sequence Annotations
  • Reference Sequence
Experimental Data & Validation

Experimental Data

  • Resolution: 1.53 Å
  • R-Value Free: 0.225 
  • R-Value Work: 0.203 
  • R-Value Observed: 0.204 
  • Space Group: P 1 21 1
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 39.571α = 90
b = 59.295β = 100.6
c = 65.337γ = 90
Software Package:
Software NamePurpose
SCALEPACKdata scaling
PDB_EXTRACTdata extraction
DENZOdata reduction

Structure Validation

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Entry History 

Deposition Data

Revision History  (Full details and data files)

  • Version 1.0: 2019-02-13
    Type: Initial release
  • Version 1.1: 2019-08-28
    Changes: Data collection, Database references
  • Version 1.2: 2023-10-04
    Changes: Data collection, Database references, Derived calculations, Refinement description