The tyrosine resides on a loop that is longer in h4EHP than in eIF4E. 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. Here we use X-ray crystallography and isothermal titration calorimetry (ITC) to investigate further the binding of cap analogues and peptides to h4EHP. 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. Human 4EHP (h4EHP) is a homologue of eIF4E.

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. 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. Diversity, Equity, Inclusion, and AccessĪll eukaryotic cellular mRNAs contain a 5' m(7)GpppN cap.Citation, Usage, Privacy Policies, Logo.

Biologically Interesting Molecule Reference Dictionary (BIRD).

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