Selenocysteine Insertion Sequence (SECIS)-binding Protein 2 Alters Conformational Dynamics of Residues Involved in tRNA Accommodation in 80 S Ribosomes
Copyright policy )Selenocysteine Insertion Sequence (SECIS)-binding Protein 2 Alters Conformational Dynamics of Residues Involved in tRNA Accommodation in 80 S Ribosomes
Sec-tRNA(Sec) is site-specifically delivered at defined UGA codons in selenoprotein mRNAs. This recoding event is specified by the selenocysteine insertion sequence (SECIS) element and requires the selenocysteine (Sec)-specific elongation factor, eEFSec, and the SECIS binding protein, SBP2. Sec-tRNA(Sec) is delivered to the ribosome by eEFSec-GTP, but this ternary complex is not sufficient for Sec incorporation, indicating that its access to the ribosomal A-site is regulated. SBP2 stably associates with ribosomes, and mutagenic analysis indicates that this interaction is essential for Sec incorporation. However, the ribosomal function of SBP2 has not been elucidated. To shed light on the functional relevance of the SBP2-ribosome interaction, we screened the functional centers of the 28 S rRNA in translationally competent 80 S ribosomes using selective 2'-hydroxyl acylation analyzed by primer extension (SHAPE). We demonstrate that SBP2 specifically alters the reactivity of specific residues in Helix 89 (H89) and expansion segment 31 (ES31). These results are indicative of a conformational change in response to SBP2 binding. Based on the known functions of H89 during translation, we propose that SBP2 allows Sec incorporation by either promoting Sec-tRNA(Sec) accommodation into the peptidyltransferase center and/or by stimulating the ribosome-dependent GTPase activity of eEFSec.
- University of Medicine and Dentistry of New Jersey United States
RNA-Binding Proteins, RNA, Transfer, Amino Acyl, GTP Phosphohydrolases, Mice, Mutagenesis, Protein Biosynthesis, Peptidyl Transferases, RNA, Ribosomal, 28S, Animals, Humans, Nucleic Acid Conformation, Ribosomes
RNA-Binding Proteins, RNA, Transfer, Amino Acyl, GTP Phosphohydrolases, Mice, Mutagenesis, Protein Biosynthesis, Peptidyl Transferases, RNA, Ribosomal, 28S, Animals, Humans, Nucleic Acid Conformation, Ribosomes
selected citations These citations are derived from selected sources.This is an alternative to the "Influence" indicator, which also reflects the overall/total impact of an article in the research community at large, based on the underlying citation network (diachronically).21 popularity This indicator reflects the "current" impact/attention (the "hype") of an article in the research community at large, based on the underlying citation network.Average influence This indicator reflects the overall/total impact of an article in the research community at large, based on the underlying citation network (diachronically).Average impulse This indicator reflects the initial momentum of an article directly after its publication, based on the underlying citation network.Top 10%
Citations provided by BIP!Popularity provided by BIP!