3CB2

Crystal structure of human gamma-tubulin bound to GDP


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.303 Å
  • R-Value Free: 0.238 
  • R-Value Work: 0.187 

wwPDB Validation 3D Report Full Report


This is version 1.1 of the entry. See complete history

Literature

The lattice as allosteric effector: structural studies of alphabeta- and gamma-tubulin clarify the role of GTP in microtubule assembly

Rice, L.M.Montabana, E.A.Agard, D.A.

(2008) Proc.Natl.Acad.Sci.Usa 105: 5378-5383

  • DOI: 10.1073/pnas.0801155105

  • PubMed Abstract: 
  • GTP-dependent microtubule polymerization dynamics are required for cell division and are accompanied by domain rearrangements in the polymerizing subunit, alphabeta-tubulin. Two opposing models describe the role of GTP and its relationship to conform ...

    GTP-dependent microtubule polymerization dynamics are required for cell division and are accompanied by domain rearrangements in the polymerizing subunit, alphabeta-tubulin. Two opposing models describe the role of GTP and its relationship to conformational change in alphabeta-tubulin. The allosteric model posits that unpolymerized alphabeta-tubulin adopts a more polymerization-competent conformation upon GTP binding. The lattice model posits that conformational changes occur only upon recruitment into the growing lattice. Published data support a lattice model, but are largely indirect and so the allosteric model has prevailed. We present two independent solution probes of the conformation of alphabeta-tubulin, the 2.3 A crystal structure of gamma-tubulin bound to GDP, and kinetic simulations to interpret the functional consequences of the structural data. These results (with our previous gamma-tubulin:GTPgammaS structure) support the lattice model by demonstrating that major domain rearrangements do not occur in eukaryotic tubulins in response to GTP binding, and that the unpolymerized conformation of alphabeta-tubulin differs significantly from the polymerized one. Thus, geometric constraints of lateral self-assembly must drive alphabeta-tubulin conformational changes, whereas GTP plays a secondary role to tune the strength of longitudinal contacts within the microtubule lattice. alphabeta-Tubulin behaves like a bent spring, resisting straightening until forced to do so by GTP-mediated interactions with the growing microtubule. Kinetic simulations demonstrate that resistance to straightening opposes microtubule initiation by specifically destabilizing early assembly intermediates that are especially sensitive to the strength of lateral interactions. These data provide new insights into the molecular origins of dynamic microtubule behavior.


    Organizational Affiliation

    Department of Biochemistry and Biophysics and Howard Hughes Medical Institute, University of California, San Francisco, CA 94158-2517, USA.




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
tubulin gamma-1 chain
A, B
475Homo sapiensMutation(s): 0 
Gene Names: TUBG1 (TUBG)
Find proteins for P23258 (Homo sapiens)
Go to Gene View: TUBG1
Go to UniProtKB:  P23258
Small Molecules
Ligands 1 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
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.303 Å
  • R-Value Free: 0.238 
  • R-Value Work: 0.187 
  • Space Group: P 1 21 1
Unit Cell:
Length (Å)Angle (°)
a = 51.744α = 90.00
b = 108.755β = 96.33
c = 83.347γ = 90.00
Software Package:
Software NamePurpose
REFMACrefinement
HKL-2000data reduction
HKL-2000data scaling
PHASERphasing
ADSCdata collection

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2008-06-10
    Type: Initial release
  • Version 1.1: 2011-07-13
    Type: Version format compliance