2JGC

Structure of the human eIF4E homologous protein, 4EHP without ligand bound


Experimental Data Snapshot

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.4 Å
  • R-Value Free: 0.249 
  • R-Value Work: 0.210 

wwPDB Validation 3D Report Full Report


This is version 1.3 of the entry. See complete history

Literature

Structures of the human eIF4E homologous protein, h4EHP, in its m7GTP-bound and unliganded forms.

Rosettani, P.Knapp, S.Vismara, M.G.Rusconi, L.Cameron, A.D.

(2007) J. Mol. Biol. 368: 691-705

  • DOI: 10.1016/j.jmb.2007.02.019
  • Primary Citation of Related Structures:  

  • PubMed Abstract: 
  • All eukaryotic cellular mRNAs contain a 5' m(7)GpppN cap. In addition to conferring stability to the mRNA, the cap is required for pre-mRNA splicing, nuclear export and translation by providing an anchor point for protein binding. In translation, the ...

    All eukaryotic cellular mRNAs contain a 5' m(7)GpppN cap. In addition to conferring stability to the mRNA, the cap is required for pre-mRNA splicing, nuclear export and translation by providing an anchor point for protein binding. In translation, the interaction between the cap and the eukaryotic initiation factor 4E (eIF4E) is important in the recruitment of the mRNAs to the ribosome. Human 4EHP (h4EHP) is a homologue of eIF4E. Like eIF4E it is able to bind the cap but it appears to play a different cellular role, possibly being involved in the fine-tuning of protein expression levels. Here we use X-ray crystallography and isothermal titration calorimetry (ITC) to investigate further the binding of cap analogues and peptides to h4EHP. m(7)GTP binds to 4EHP 200-fold more weakly than it does to eIF4E with the guanine base sandwiched by a tyrosine and a tryptophan instead of two tryptophan residues as seen in eIF4E. The tyrosine resides on a loop that is longer in h4EHP than in eIF4E. The consequent conformational difference between the proteins allows the tyrosine to mimic the six-membered ring of the tryptophan in eIF4E and adopt an orientation that is similar to that seen for equivalent residues in other non-homologous cap-binding proteins. In the absence of ligand the binding site is incompletely formed with one of the aromatic residues being disordered and the side-chain of the other adopting a novel conformation. A peptide derived from the eIF4E inhibitory protein, 4E-BP1 binds h4EHP 100-fold less strongly than eIF4E but in a similar manner. Overall the data, combined with sequence analyses of 4EHP from evolutionary diverse species, strongly support the hypothesis that 4EHP plays a physiological role utilizing both cap-binding and protein-binding functions but which is distinct from eIF4E.


    Organizational Affiliation

    Department of Chemistry, Nerviano Medical Sciences S.r.l., viale Pasteur 10, 20014 Nerviano, Milan, Italy.




Macromolecules

Find similar proteins by: Sequence  |  Structure

Entity ID: 1
MoleculeChainsSequence LengthOrganismDetails
EUKARYOTIC TRANSLATION INITIATION FACTOR 4E TYPE 2
A
195Homo sapiensMutation(s): 0 
Gene Names: EIF4E2 (EIF4EL3)
Find proteins for O60573 (Homo sapiens)
Go to Gene View: EIF4E2
Go to UniProtKB:  O60573
Entity ID: 2
MoleculeChainsSequence LengthOrganismDetails
EUKARYOTIC TRANSLATION INITIATION FACTOR 4E-BINDING PROTEIN 1
B
17Homo sapiensMutation(s): 0 
Gene Names: EIF4EBP1
Find proteins for Q13541 (Homo sapiens)
Go to Gene View: EIF4EBP1
Go to UniProtKB:  Q13541
Experimental Data & Validation

Experimental Data

  • Method: X-RAY DIFFRACTION
  • Resolution: 2.4 Å
  • R-Value Free: 0.249 
  • R-Value Work: 0.210 
  • Space Group: P 21 21 21
Unit Cell:
Length (Å)Angle (°)
a = 43.499α = 90.00
b = 49.299β = 90.00
c = 103.767γ = 90.00
Software Package:
Software NamePurpose
REFMACphasing
MOSFLMdata reduction
REFMACrefinement
SCALAdata scaling

Structure Validation

View Full Validation Report or Ramachandran Plots



Entry History 

Deposition Data

Revision History 

  • Version 1.0: 2007-02-27
    Type: Initial release
  • Version 1.1: 2011-05-08
    Type: Version format compliance
  • Version 1.2: 2011-07-13
    Type: Version format compliance
  • Version 1.3: 2018-03-28
    Type: Database references, Source and taxonomy