Conserved motifs in prokaryotic and eukaryotic polypeptide release factors: tRNA-protein mimicry hypothesis.

• DOI: 10.1073/pnas.93.11.5443
• Publication Date: 2002-07-26T14:34:16Z
• Authors: K Ito; K Ebihara; M Uno; Y Nakamura
• Keywords: Release factor; Elongation factor; Conserved sequence

Translation termination requires two codon-specific polypeptide release factors in prokaryotes and one omnipotent factor eukaryotes. Sequences of 17 different from eukaryotes were compared. The prokaryotic share residues split into seven motifs. Conservation many discrete, perhaps critical, amino acids is observed eukaryotic factors, as well the C-terminal portion elongation (EF) G. Given that domains EF-G interacts with ribosomes by mimicry a tRNA structure, pattern conservation may reflect requirements for tRNA-mimicry binding to A site ribosome. This would explain why recognize stop codons suggests all evolved progenitor EF-G.