Coupled tRNA(Sec)-dependent assembly of the selenocysteine decoding apparatus

• Published in: Molecular cell 2003-03, Vol.11 (3), p.773
• Main Authors: Zavacki, Ann Marie, Mansell, John B, Chung, Mirra, Klimovitsky, Boris, Harney, John W, Berry, Marla J
• Format: Article
• Language: English
• Subjects: Amino Acid Sequence; Animals; Binding Sites; Blotting, Western; Codon; Cysteine - metabolism; DNA Mutational Analysis; Gene Deletion; Glutathione Transferase - metabolism; Humans; Methionine - metabolism; Mice; Models, Biological; Molecular Sequence Data; Mutagenesis, Site-Directed; Nucleic Acid Conformation; Plasmids - metabolism; Point Mutation; Precipitin Tests; Protein Binding; Protein Biosynthesis; Protein Conformation; Protein Structure, Tertiary; Recombinant Fusion Proteins - metabolism; Ribosomes - metabolism; RNA, Transfer, Amino Acid-Specific - metabolism; Selenocysteine - genetics; Selenocysteine - metabolism; Sequence Homology, Amino Acid; Transfection
• ISSN: 1097-2765
• DOI: 10.1016/S1097-2765(03)00064-9

SECIS elements recode UGA codons from "stop" to "sense." These RNA secondary structures, present in eukaryotic selenoprotein mRNA 3' untranslated regions, recruit a SECIS binding protein, which recruits a selenocysteine-specific elongation factor-tRNA complex. Elucidation of the assembly of this multicomponent complex is crucial to understanding the mechanism of selenocysteine incorporation. Coprecipitation studies identified the C-terminal 64 amino acids of the elongation factor as sufficient for interaction with the SECIS binding protein. Selenocysteyl-tRNA is required for this interaction; the two factors do not coprecipitate in its absence. Finally, through promoting this interaction, selenocysteyl-tRNA stabilizes the C-terminal domain of the elongation factor. We suggest that the coupling effect is critical to preventing nonproductive decoding attempts and hence forms a basis for effective selenoprotein synthesis.