1GIA

STRUCTURE OF ACTIVE CONFORMATIONS OF GIA1 AND THE MECHANISM OF GTP HYDROLYSIS


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.00 Å
  • R-Value Free: 0.228 
  • R-Value Work: 0.175 
  • R-Value Observed: 0.175 

wwPDB Validation   3D Report Full Report


This is version 1.2 of the entry. See complete history


Literature

Structures of active conformations of Gi alpha 1 and the mechanism of GTP hydrolysis.

Coleman, D.E.Berghuis, A.M.Lee, E.Linder, M.E.Gilman, A.G.Sprang, S.R.

(1994) Science 265: 1405-1412

  • DOI: 10.1126/science.8073283
  • Primary Citation of Related Structures:  
    1GFI, 1GIA, 1GIL

  • PubMed Abstract: 
  • Mechanisms of guanosine triphosphate (GTP) hydrolysis by members of the G protein alpha subunit-p21ras superfamily of guanosine triphosphatases have been studied extensively but have not been well understood. High-resolution x-ray structures of the GTP gamma S and GDP ...

    Mechanisms of guanosine triphosphate (GTP) hydrolysis by members of the G protein alpha subunit-p21ras superfamily of guanosine triphosphatases have been studied extensively but have not been well understood. High-resolution x-ray structures of the GTP gamma S and GDP.AlF4- complexes formed by the G protein Gi alpha 1 demonstrate specific roles in transition-state stabilization for two highly conserved residues. Glutamine204 (Gln61 in p21ras) stabilizes and orients the hydrolytic water in the trigonal-bipyramidal transition state. Arginine 178 stabilizes the negative charge at the equatorial oxygen atoms of the pentacoordinate phosphate intermediate. Conserved only in the G alpha family, this residue may account for the higher hydrolytic rate of G alpha proteins relative to those of the p21ras family members. The fold of Gi alpha 1 differs from that of the homologous Gt alpha subunit in the conformation of a helix-loop sequence located in the alpha-helical domain that is characteristic of these proteins; this site may participate in effector binding. The amino-terminal 33 residues are disordered in GTP gamma S-Gi alpha 1, suggesting a mechanism that may promote release of the beta gamma subunit complex when the alpha subunit is activated by GTP.


    Related Citations: 
    • Crystallization and Preliminary Crystallographic Studies of Gia1 and Mutants of Gia1 in the GTP and Gdp-Bound States
      Coleman, D.E., Lee, E., Mixon, M.B., Linder, M.E., Berghuis, A.M., Gilman, A.G., Sprang, S.R.
      (1994) J Mol Biol 238: 630

    Organizational Affiliation

    Howard Hughes Medical Institute, Dallas, TX.



Macromolecules
Find similar proteins by:  (by identity cutoff)  |  3D Structure
Entity ID: 1
MoleculeChainsSequence LengthOrganismDetailsImage
G PROTEIN GI ALPHA 1A353Rattus norvegicusMutation(s): 0 
Gene Names: Gnai1Gnai-1
UniProt
Find proteins for P10824 (Rattus norvegicus)
Explore P10824 
Go to UniProtKB:  P10824
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupP10824
Protein Feature View
Expand
  • Reference Sequence
Small Molecules
Ligands 2 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
GSP
Query on GSP

Download Ideal Coordinates CCD File 
C [auth A]5'-GUANOSINE-DIPHOSPHATE-MONOTHIOPHOSPHATE
C10 H16 N5 O13 P3 S
XOFLBQFBSOEHOG-UUOKFMHZSA-N
 Ligand Interaction
MG
Query on MG

Download Ideal Coordinates CCD File 
B [auth A]MAGNESIUM ION
Mg
JLVVSXFLKOJNIY-UHFFFAOYSA-N
 Ligand Interaction
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.00 Å
  • R-Value Free: 0.228 
  • R-Value Work: 0.175 
  • R-Value Observed: 0.175 
  • Space Group: P 32 2 1
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 80.6α = 90
b = 80.6β = 90
c = 106.5γ = 120
Software Package:
Software NamePurpose
X-PLORmodel building
X-PLORrefinement
X-PLORphasing

Structure Validation

View Full Validation Report




Entry History 

Deposition Data

Revision History  (Full details and data files)

  • Version 1.0: 1994-09-30
    Type: Initial release
  • Version 1.1: 2008-03-24
    Changes: Version format compliance
  • Version 1.2: 2011-07-13
    Changes: Version format compliance