Ribosomal protein L30 is a component of the UGA-selenocysteine recoding machinery in eukaryotes.
The translational recoding of UGA as selenocysteine (Sec) is directed by a SECIS element in the 3' untranslated region (UTR) of eukaryotic selenoprotein mRNAs. The selenocysteine insertion sequence (SECIS) contains two essential tandem sheared G.A pairs that bind SECIS-binding protein 2 (SBP2), which recruits a selenocysteine-specific elongation factor and Sec-tRNA(Sec) to the ribosome. Here we show that ribosomal protein L30 is a component of the eukaryotic selenocysteine recoding machinery. L30 binds SECIS elements in vitro and in vivo, stimulates UGA recoding in transfected cells and competes with SBP2 for SECIS binding. Magnesium, known to induce a kink-turn in RNAs that contain two tandem G.A pairs, decreases the SBP2-SECIS complex in favor of the L30-SECIS interaction. We propose a model in which SBP2 and L30 carry out different functions in the UGA recoding mechanism, with the SECIS acting as a molecular switch upon protein binding.
Chavatte
Laurent
L
Department of Cell Biology, Lerner Research Institute, Cleveland Clinic Foundation, Cleveland, Ohio 44195, USA.
Brown
Bernard A
BA
Driscoll
Donna M
DM
D020413:3' Untranslated Regions / Q000235:genetics; D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D003062:Codon / Q000235:genetics*; D018388:Codon, Terminator / Q000235:genetics; D005057:Eukaryotic Cells / Q000378:metabolism*; D008969:Molecular Sequence Data; D009690:Nucleic Acid Conformation; D011485:Protein Binding; D017433:Protein Structure, Secondary; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D016601:RNA-Binding Proteins / Q000378:metabolism; D051381:Rats; D012269:Ribosomal Proteins / Q000737:chemistry / Q000302:isolation & purification / Q000378:metabolism*; D017279:Selenocysteine / Q000235:genetics* / Q000378:metabolism*; D016415:Sequence Alignment
D020413:3' Untranslated Regions; D003062:Codon; D018388:Codon, Terminator; D012333:RNA, Messenger; D016601:RNA-Binding Proteins; D012269:Ribosomal Proteins; C035201:ribosomal protein L30; C119984:selenocysteine insertion sequence binding protein, mammalian; D017279:Selenocysteine