Crystal Structure of gamma-tubulin bound to GTP

Experimental Data Snapshot

  • Resolution: 3.00 Å
  • R-Value Free: 0.309 
  • R-Value Work: 0.247 
  • R-Value Observed: 0.247 

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This is version 1.3 of the entry. See complete history


Insights into microtubule nucleation from the crystal structure of human gamma-tubulin.

Aldaz, H.Rice, L.M.Stearns, T.Agard, D.A.

(2005) Nature 435: 523-527

  • DOI: https://doi.org/10.1038/nature03586
  • Primary Citation of Related Structures:  
    1Z5V, 1Z5W

  • PubMed Abstract: 

    Microtubules are hollow polymers of alphabeta-tubulin that show GTP-dependent assembly dynamics and comprise a critical part of the eukaryotic cytoskeleton. Initiation of new microtubules in vivo requires gamma-tubulin, organized as an oligomer within the 2.2-MDa gamma-tubulin ring complex (gamma-TuRC) of higher eukaryotes. Structural insight is lacking regarding gamma-tubulin, its oligomerization and how it promotes microtubule assembly. Here we report the 2.7-A crystal structure of human gamma-tubulin bound to GTP-gammaS (a non-hydrolysable GTP analogue). We observe a 'curved' conformation for gamma-tubulin-GTPgammaS, similar to that seen for GDP-bound, unpolymerized alphabeta-tubulin. Tubulins are thought to represent a distinct class of GTP-binding proteins, and conformational switching in gamma-tubulin might differ from the nucleotide-dependent switching of signalling GTPases. A crystal packing interaction replicates the lateral contacts between alpha- and beta-tubulins in the microtubule, and this association probably forms the basis for gamma-tubulin oligomerization within the gamma-TuRC. Laterally associated gamma-tubulins in the gamma-TuRC might promote microtubule nucleation by providing a template that enhances the intrinsically weak lateral interaction between alphabeta-tubulin heterodimers. Because they are dimeric, alphabeta-tubulins cannot form microtubule-like lateral associations in the curved conformation. The lateral array of gamma-tubulins we observe in the crystal reveals a unique functional property of a monomeric tubulin.

  • Organizational Affiliation

    Howard Hughes Medical Institute and Department of Biochemistry and Biophysics, University of California, San Francisco, 600 16th Street, San Francisco, California 94143, USA.

Find similar proteins by:  (by identity cutoff)  |  3D Structure
Entity ID: 1
MoleculeChains Sequence LengthOrganismDetailsImage
Tubulin gamma-1 chain474Homo sapiensMutation(s): 0 
Gene Names: TUBG1TUBG
UniProt & NIH Common Fund Data Resources
Find proteins for P23258 (Homo sapiens)
Explore P23258 
Go to UniProtKB:  P23258
GTEx:  ENSG00000131462 
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupP23258
Sequence Annotations
  • Reference Sequence
Small Molecules
Ligands 2 Unique
IDChains Name / Formula / InChI Key2D Diagram3D Interactions
Query on GTP

Download Ideal Coordinates CCD File 
C10 H16 N5 O14 P3
Query on MG

Download Ideal Coordinates CCD File 
Experimental Data & Validation

Experimental Data

  • Resolution: 3.00 Å
  • R-Value Free: 0.309 
  • R-Value Work: 0.247 
  • R-Value Observed: 0.247 
  • Space Group: P 1 21 1
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 52.19α = 90
b = 76.29β = 102.31
c = 64.81γ = 90
Software Package:
Software NamePurpose
HKL-2000data reduction
SCALEPACKdata scaling

Structure Validation

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Ligand Structure Quality Assessment 

Entry History 

Deposition Data

Revision History  (Full details and data files)

  • Version 1.0: 2005-05-31
    Type: Initial release
  • Version 1.1: 2008-04-30
    Changes: Version format compliance
  • Version 1.2: 2011-07-13
    Changes: Version format compliance
  • Version 1.3: 2023-08-23
    Changes: Data collection, Database references, Derived calculations, Refinement description