1BOF

GI-ALPHA-1 BOUND TO GDP AND MAGNESIUM


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.2 Å
  • R-Value Free: 0.268 
  • R-Value Work: 0.227 

wwPDB Validation 3D Report Full Report


This is version 1.2 of the entry. See complete history

Literature

Crystal structures of the G protein Gi alpha 1 complexed with GDP and Mg2+: a crystallographic titration experiment.

Coleman, D.E.Sprang, S.R.

(1998) Biochemistry 37: 14376-14385

  • DOI: 10.1021/bi9810306

  • PubMed Abstract: 
  • The effect of Mg2+ binding on the conformation of the inactive GDP-bound complex of the heterotrimeric G protein alpha subunit Gi alpha 1 has been investigated by X-ray crystallography. Crystal structures of the Gi alpha 1.GDP complex were determined ...

    The effect of Mg2+ binding on the conformation of the inactive GDP-bound complex of the heterotrimeric G protein alpha subunit Gi alpha 1 has been investigated by X-ray crystallography. Crystal structures of the Gi alpha 1.GDP complex were determined after titration with 5, 10, 100, and 200 mM Mg2+. Comparison of these structures with that of the Mg2+-free complex revealed Mg2+ bound at the same site as observed in the structure of the active, Gi alpha 1. GTP gamma S.Mg2+-bound complex of Gi alpha 1, with a similar coordination scheme except for the substitution of a water molecule for an oxygen ligand of the gamma-phosphate of Gi alpha 1.GTP gamma S. Mg2+. In contrast to the GDP.Mg2+ complex of Gt alpha and of other G proteins, switch I residues of Gi alpha 1 participate in Mg2+ binding and undergo conformational changes as a consequence of Mg2+ binding. Partial order is induced in switch II, which is disordered in the Mg2+-free complex, but no order is observed in the switch III region. This contrasts with the GDP.Mg2+ complex of Gt alpha in which both switch II and III switch are ordered. Mg2+ binding also induces binding of an SO42- molecule to the active site in a manner which may mimic a Gi alpha 1.GDP.PO42-.Mg2+ product complex. Implications of these findings are discussed.


    Related Citations: 
    • 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
    • Crystallization and Preliminary Crystallographic Studies of Gi Alpha 1 and Mutants of Gi Alpha 1 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
    • Tertiary and Quaternary Structural Changes in Gi Alpha 1 Induced by GTP Hydrolysis
      Mixon, M.B.,Lee, E.,Coleman, D.E.,Berghuis, A.M.,Gilman, A.G.,Sprang, S.R.
      (1995) Science 270: 954


    Organizational Affiliation

    Howard Hughes Medical Institute, Department of Biochemistry, The University of Texas Southwestern Medical Center, Dallas 75235-9050, USA.




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
GI ALPHA 1
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
GDP
Query on GDP

Download SDF File 
Download CCD File 
A
GUANOSINE-5'-DIPHOSPHATE
C10 H15 N5 O11 P2
QGWNDRXFNXRZMB-UUOKFMHZSA-N
 Ligand Interaction
SO4
Query on SO4

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

Download SDF File 
Download CCD File 
A
MAGNESIUM ION
Mg
JLVVSXFLKOJNIY-UHFFFAOYSA-N
 Ligand Interaction
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.2 Å
  • R-Value Free: 0.268 
  • R-Value Work: 0.227 
  • Space Group: I 4
Unit Cell:
Length (Å)Angle (°)
a = 121.747α = 90.00
b = 121.747β = 90.00
c = 68.929γ = 90.00
Software Package:
Software NamePurpose
X-PLORmodel building
X-PLORrefinement
DENZOdata reduction
X-PLORphasing
SCALEPACKdata scaling

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 1999-01-06
    Type: Initial release
  • Version 1.1: 2008-03-24
    Type: Version format compliance
  • Version 1.2: 2011-07-13
    Type: Version format compliance