1GIA

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


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2 Å
  • R-Value Free: 0.228 
  • R-Value Work: 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

  • Primary Citation of Related Structures:  

  • 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 G ...

    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: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
G PROTEIN GI ALPHA 1
A
353Rattus norvegicusMutation(s): 0 
Gene Names: Gnai1 (Gnai-1)
Find proteins for P10824 (Rattus norvegicus)
Go to UniProtKB:  P10824
Small Molecules
Ligands 2 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
MG
Query on MG

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

Download SDF File 
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: 0.228 
  • R-Value Work: 0.175 
  • Space Group: P 32 2 1
Unit Cell:
Length (Å)Angle (°)
a = 80.600α = 90.00
b = 80.600β = 90.00
c = 106.500γ = 120.00
Software Package:
Software NamePurpose
X-PLORphasing
X-PLORmodel building
X-PLORrefinement

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

Revision History 

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