3ONW

Structure of a G-alpha-i1 mutant with enhanced affinity for the RGS14 GoLoco motif.


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.38 Å
  • R-Value Free: 0.265 
  • R-Value Work: 0.228 

wwPDB Validation 3D Report Full Report


This is version 1.1 of the entry. See complete history

Literature

Structural Determinants of Affinity Enhancement between GoLoco Motifs and G-Protein {alpha} Subunit Mutants.

Bosch, D.E.Kimple, A.J.Sammond, D.W.Muller, R.E.Miley, M.J.Machius, M.Kuhlman, B.Willard, F.S.Siderovski, D.P.

(2011) J.Biol.Chem. 286: 3351-3358

  • DOI: 10.1074/jbc.M110.190496

  • PubMed Abstract: 
  • GoLoco motif proteins bind to the inhibitory G(i) subclass of G-protein α subunits and slow the release of bound GDP; this interaction is considered critical to asymmetric cell division and neuro-epithelium and epithelial progenitor differentiation. ...

    GoLoco motif proteins bind to the inhibitory G(i) subclass of G-protein α subunits and slow the release of bound GDP; this interaction is considered critical to asymmetric cell division and neuro-epithelium and epithelial progenitor differentiation. To provide protein tools for interrogating the precise cellular role(s) of GoLoco motif/Gα(i) complexes, we have employed structure-based protein design strategies to predict gain-of-function mutations that increase GoLoco motif binding affinity. Here, we describe fluorescence polarization and isothermal titration calorimetry measurements showing three predicted Gα(i1) point mutations, E116L, Q147L, and E245L; each increases affinity for multiple GoLoco motifs. A component of this affinity enhancement results from a decreased rate of dissociation between the Gα mutants and GoLoco motifs. For Gα(i1)(Q147L), affinity enhancement was seen to be driven by favorable changes in binding enthalpy, despite reduced contributions from binding entropy. The crystal structure of Gα(i1)(Q147L) bound to the RGS14 GoLoco motif revealed disorder among three peptide residues surrounding a well defined Leu-147 side chain. Monte Carlo simulations of the peptide in this region showed a sampling of multiple backbone conformations in contrast to the wild-type complex. We conclude that mutation of Glu-147 to leucine creates a hydrophobic surface favorably buried upon GoLoco peptide binding, yet the hydrophobic Leu-147 also promotes flexibility among residues 511-513 of the RGS14 GoLoco peptide.


    Related Citations: 
    • Structural determinants for GoLoco-induced inhibition of nucleotide release by Galpha subunits
      Kimple, R.J.,Kimple, M.E.,Betts, L.,Sondek, J.,Siderovski, D.P.
      (2002) Nature 416: 878
    • Structure-based protocol for identifying mutations that enhance protein-protein binding affinities
      Sammond, D.W.,Eletr, Z.M.,Purbeck, C.,Kimple, R.J.,Siderovski, D.P.,Kuhlman, B.
      (2007) J.Mol.Biol. 371: 1392


    Organizational Affiliation

    Department of Pharmacology, University of North Carolina, Chapel Hill, North Carolina 27599, USA.




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
Guanine nucleotide-binding protein G(i) subunit alpha-1
A, B
328Homo sapiensMutation(s): 1 
Gene Names: GNAI1
Find proteins for P63096 (Homo sapiens)
Go to Gene View: GNAI1
Go to UniProtKB:  P63096
Entity ID: 2
MoleculeChainsSequence LengthOrganismDetails
Regulator of G-protein signaling 14
C, D
36Homo sapiensMutation(s): 0 
Gene Names: RGS14
Find proteins for O43566 (Homo sapiens)
Go to Gene View: RGS14
Go to UniProtKB:  O43566
Small Molecules
Ligands 2 Unique
IDChainsName / Formula / InChI Key2D Diagram3D Interactions
GDP
Query on GDP

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

Download SDF File 
Download CCD File 
A, B
SULFATE ION
O4 S
QAOWNCQODCNURD-UHFFFAOYSA-L
 Ligand Interaction
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.38 Å
  • R-Value Free: 0.265 
  • R-Value Work: 0.228 
  • Space Group: P 2 2 21
Unit Cell:
Length (Å)Angle (°)
a = 70.392α = 90.00
b = 83.679β = 90.00
c = 190.148γ = 90.00
Software Package:
Software NamePurpose
HKL-2000data scaling
REFMACrefinement
PHASERphasing
HKL-2000data reduction

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2010-11-24
    Type: Initial release
  • Version 1.1: 2011-07-13
    Type: Version format compliance