1AS0

GTP-GAMMA-S BOUND G42V GIA1


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2 Å
  • R-Value Free: 0.259 
  • R-Value Work: 0.206 

wwPDB Validation 3D Report Full Report


This is version 1.2 of the entry. See complete history

Literature

Structural and biochemical characterization of the GTPgammaS-, GDP.Pi-, and GDP-bound forms of a GTPase-deficient Gly42 --> Val mutant of Gialpha1.

Raw, A.S.Coleman, D.E.Gilman, A.G.Sprang, S.R.

(1997) Biochemistry 36: 15660-15669

  • DOI: 10.1021/bi971912p
  • Primary Citation of Related Structures:  1AS2, 1AS3

  • PubMed Abstract: 
  • The Gly42 --> Val mutant of Gialpha1 was characterized structurally and biochemically to elucidate two important features of Gialpha1-catalyzed GTP hydrolysis. The crystal structure of the GTPgammaS-bound G42VGialpha1 protein demonstrates that the st ...

    The Gly42 --> Val mutant of Gialpha1 was characterized structurally and biochemically to elucidate two important features of Gialpha1-catalyzed GTP hydrolysis. The crystal structure of the GTPgammaS-bound G42VGialpha1 protein demonstrates that the steric bulk of Val42 pushes the Gln204 residue into a catalytically incompetent conformation, providing a rationale for the diminished GTPase activity of this mutant. The same phenomenon may also account for the diminished GTPase activity of the homologous transforming Gly42 --> Val mutation in p21(ras). Similarly, the steric bulk of the unique Ser42 residue in Gzalpha may account for the comparatively slower rate of GTP hydrolysis by this Galpha subunit. The G42VGialpha1 subunit was also characterized structurally in its GDP.Pi- and GDP-bound states, providing a unique opportunity to view three "snapshots" of GTP hydrolysis. Hydrolysis of GTP to a transient GDP.Pi-bound intermediate is associated with substantial conformational changes in the switch II segment of the protein. Eventual release of Pi results in further removal of switch I from the active site and a highly mobile switch II segment. Despite their disparate biochemical properties, the structural similarity of G42VGialpha1 to the G203AGialpha1 mutant in the GDP.Pi-bound form suggests that both mutations stabilize a conformation of the GDP. Pi-bound protein that occurs only transiently in the wild-type protein. The structures of the GDP-bound forms of the wild-type and mutant proteins are similar.


    Organizational Affiliation

    Department of Pharmacology, and Howard Hughes Medical Institute, University of Texas Southwestern Medical Center, Dallas, Texas 75235, USA.




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
GIA1
A
353Rattus norvegicusGene Names: Gnai1 (Gnai-1)
Find proteins for P10824 (Rattus norvegicus)
Go to UniProtKB:  P10824
Small Molecules
Ligands 3 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
SO4
Query on SO4

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Download CCD File 
A
SULFATE ION
O4 S
QAOWNCQODCNURD-UHFFFAOYSA-L
 Ligand Interaction
MG
Query on MG

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Download CCD File 
A
MAGNESIUM ION
Mg
JLVVSXFLKOJNIY-UHFFFAOYSA-N
 Ligand Interaction
GSP
Query on GSP

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Download CCD File 
A
5'-GUANOSINE-DIPHOSPHATE-MONOTHIOPHOSPHATE
C10 H16 N5 O13 P3 S
XOFLBQFBSOEHOG-UUOKFMHZSA-N
 Ligand Interaction
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2 Å
  • R-Value Free: 0.259 
  • R-Value Work: 0.206 
  • Space Group: P 32 2 1
Unit Cell:
Length (Å)Angle (°)
a = 78.950α = 90.00
b = 78.950β = 90.00
c = 105.290γ = 120.00
Software Package:
Software NamePurpose
DENZOdata reduction
X-PLORmodel building
SCALEPACKdata scaling
X-PLORphasing
X-PLORrefinement

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 1997-11-12
    Type: Initial release
  • Version 1.1: 2008-03-24
    Type: Version format compliance
  • Version 1.2: 2011-07-13
    Type: Version format compliance