Crystal structure of human eIF2B alpha

Experimental Data Snapshot

  • Resolution: 2.65 Å
  • R-Value Free: 0.273 
  • R-Value Work: 0.214 

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Crystal structure of the alpha subunit of human translation initiation factor 2B

Hiyama, T.B.Ito, T.Imataka, H.Yokoyama, S.

(2009) J Mol Biol 392: 937-951

  • DOI: https://doi.org/10.1016/j.jmb.2009.07.054
  • Primary Citation of Related Structures:  

  • PubMed Abstract: 

    Eukaryotic translation initiation factor 2B (eIF2B) is the heteropentameric guanine-nucleotide exchange factor specific for eukaryotic initiation factor 2 (eIF2). Under stressed conditions, guanine-nucleotide exchange is strongly inhibited by the tight binding of phosphorylated eIF2 to eIF2B. Here, we report the crystal structure of the alpha subunit of human eIF2B at 2.65 A resolution. The eIF2Balpha structure consists of the N-terminal alpha-helical domain and the C-terminal Rossmann-fold-like domain. A positively charged pocket, whose entrance is about 15-17 A in diameter, resides at the boundary between the two domains. A sulfate ion is located at the bottom of the pocket (about 16 A in depth). The residues comprising the sulfate-ion-binding site are strictly conserved in eIF2Balpha. Since this deep, wide pocket with the sulfate-ion-binding site is not conserved in distant homologues, including 5-methylthioribose 1-phosphate isomerases, these characteristics may be distinctive of eIF2Balpha. Interestingly, the yeast eIF2Balpha missense mutations that reduce the eIF2B sensitivity to phosphorylated eIF2 are mapped on the other side of the pocket. One of the three human eIF2Balpha missense mutations that induce the lethal brain disorder vanishing white matter or childhood ataxia with central nervous system hypomyelination is mapped inside the pocket. The beta and delta subunits of eIF2B are homologous to eIF2Balpha and may have tertiary structures similar to the present eIF2Balpha structure. The sulfate-ion-binding residues of eIF2Balpha are well conserved in eIF2Bbeta/delta. The abovementioned yeast and human missense mutations of eIF2Bbeta/delta were also mapped on the eIF2Balpha structure, which revealed that the human mutations are clustered on the same side as the pocket, while the yeast mutations reside on the opposite side. As most of the mutated residues are exposed on the surface of the eIF2B subunit structure, these exposed residues are likely to be involved in either the subunit interactions or the interaction with eIF2.

  • Organizational Affiliation

    Department of Biophysics and Biochemistry, Graduate School of Science, the University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan.

Find similar proteins by:  (by identity cutoff)  |  3D Structure
Entity ID: 1
MoleculeChains Sequence LengthOrganismDetailsImage
Translation initiation factor eIF-2B subunit alpha
A, B, C, D, E
A, B, C, D, E, F, G, H
315Homo sapiensMutation(s): 0 
UniProt & NIH Common Fund Data Resources
Find proteins for Q14232 (Homo sapiens)
Explore Q14232 
Go to UniProtKB:  Q14232
PHAROS:  Q14232
GTEx:  ENSG00000111361 
Entity Groups  
Sequence Clusters30% Identity50% Identity70% Identity90% Identity95% Identity100% Identity
UniProt GroupQ14232
Sequence Annotations
  • Reference Sequence
Small Molecules
Ligands 2 Unique
IDChains Name / Formula / InChI Key2D Diagram3D Interactions
Query on SO4

Download Ideal Coordinates CCD File 
I [auth A]
J [auth A]
L [auth B]
M [auth C]
N [auth D]
I [auth A],
J [auth A],
L [auth B],
M [auth C],
N [auth D],
O [auth E],
P [auth F],
Q [auth F],
R [auth G],
S [auth H]
O4 S
Query on CL

Download Ideal Coordinates CCD File 
Modified Residues  1 Unique
IDChains TypeFormula2D DiagramParent
Query on MSE
A, B, C, D, E
A, B, C, D, E, F, G, H
Experimental Data & Validation

Experimental Data

  • Resolution: 2.65 Å
  • R-Value Free: 0.273 
  • R-Value Work: 0.214 
  • Space Group: P 1 21 1
Unit Cell:
Length ( Å )Angle ( ˚ )
a = 70.885α = 90
b = 156.394β = 104.2
c = 138.441γ = 90
Software Package:
Software NamePurpose
HKL-2000data collection
HKL-2000data reduction
HKL-2000data scaling

Structure Validation

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Entry History 

Deposition Data

Revision History  (Full details and data files)

  • Version 1.0: 2009-09-01
    Type: Initial release
  • Version 1.1: 2011-07-13
    Changes: Version format compliance
  • Version 1.2: 2014-02-05
    Changes: Database references