3ECS

Crystal structure of human eIF2B alpha


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.65 Å
  • R-Value Free: 0.273 
  • R-Value Work: 0.214 

wwPDB Validation   3D Report Full Report


This is version 1.2 of the entry. See complete history


Literature

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: 10.1016/j.jmb.2009.07.054
  • Primary Citation of Related Structures:  
    3ECS

  • 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 ...

    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.



Macromolecules
Find similar proteins by:  (by identity cutoff)  |  Structure
Entity ID: 1
MoleculeChainsSequence LengthOrganismDetailsImage
Translation initiation factor eIF-2B subunit alphaA, B, C, D, E, F, G, H315Homo sapiensMutation(s): 0 
Gene Names: EIF2B1EIF2BA
UniProt & NIH Common Fund Data Resources
Find proteins for Q14232 (Homo sapiens)
Explore Q14232 
Go to UniProtKB:  Q14232
PHAROS:  Q14232
Protein Feature View
Expand
  • Reference Sequence
Small Molecules
Modified Residues  1 Unique
IDChainsTypeFormula2D DiagramParent
MSE
Query on MSE
A, B, C, D, E, F, G, HL-PEPTIDE LINKINGC5 H11 N O2 SeMET
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • 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
autoSHARPphasing
CNSrefinement
HKL-2000data reduction
HKL-2000data scaling

Structure Validation

View Full Validation Report



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