Backbone (1)H, (13)C and (15)N resonance assignments of the human eukaryotic release factor eRF1.

Eukaryotic translation termination is mediated by two interacting release factors, eukaryotic class 1 release factor (eRF1) and eukaryotic class 3 release factor (eRF3), which act cooperatively to ensure efficient stop codon recognition and fast polypeptide release. eRF1 consisting of three well-defined functional domains recognizes all three mRNA stop codons located in the A site of the small ribosomal subunit and triggers hydrolysis of the ester bond of peptidyl-tRNA in the peptidyl transfer center of the large ribosomal subunit. Nevertheless, various aspects of molecular mechanism of translation termination in eukaryotes remain unclear.

Structure and dynamics in solution of the stop codon decoding N-terminal domain of the human polypeptide chain release factor eRF1.

The high-resolution NMR structure of the N-domain of human eRF1, responsible for stop codon recognition, has been determined in solution. The overall fold of the protein is the same as that found in the crystal structure. However, the structures of several loops, including those participating in stop codon decoding, are different.

The crucial role of conserved intermolecular H-bonds inaccessible to the solvent in formation and stabilization of the TL5.5 SrRNA complex.

Analysis of the structures of two complexes of 5 S rRNA with homologous ribosomal proteins, Escherichia coli L25 and Thermus thermophilus TL5, revealed that amino acid residues interacting with RNA can be divided into two different groups. The first group consists of non-conserved residues, which form intermolecular hydrogen bonds accessible to solvent. The second group, comprised of strongly conserved residues, form intermolecular hydrogen bonds that are shielded from solvent.