Coupled tRNA(Sec)-dependent assembly of the selenocysteine decoding apparatus.
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.
Zavacki
Ann Marie
AM
Thyroid Division, Department of Medicine, Brigham and Women's Hospital and Harvard Medical School, Boston, MA 02115, USA.
Mansell
John B
JB
Chung
Mirra
M
Klimovitsky
Boris
B
Harney
John W
JW
Berry
Marla J
MJ
D000595:Amino Acid Sequence; D000818:Animals; D001665:Binding Sites; D015153:Blotting, Western; D003062:Codon; D003545:Cysteine / Q000378:metabolism; D004252:DNA Mutational Analysis; D017353:Gene Deletion; D005982:Glutathione Transferase / Q000378:metabolism; D006801:Humans; D008715:Methionine / Q000378:metabolism; D051379:Mice; D008954:Models, Biological; D008969:Molecular Sequence Data; D016297:Mutagenesis, Site-Directed; D009690:Nucleic Acid Conformation; D010957:Plasmids / Q000378:metabolism; D017354:Point Mutation; D011233:Precipitin Tests; D011485:Protein Binding; D014176:Protein Biosynthesis; D011487:Protein Conformation; D017434:Protein Structure, Tertiary; D012345:RNA, Transfer, Amino Acid-Specific / Q000378:metabolism*; D011993:Recombinant Fusion Proteins / Q000378:metabolism; D012270:Ribosomes / Q000378:metabolism; D017279:Selenocysteine / Q000235:genetics* / Q000378:metabolism*; D017386:Sequence Homology, Amino Acid; D014162:Transfection
D003062:Codon; D012345:RNA, Transfer, Amino Acid-Specific; D011993:Recombinant Fusion Proteins; C036928:tRNA, selenocysteine-; D017279:Selenocysteine; D008715:Methionine; D005982:Glutathione Transferase; D003545:Cysteine