4jv5
Crystal structures of pseudouridinilated stop codons with ASLsCrystal structures of pseudouridinilated stop codons with ASLs
Structural highlights
FunctionRS4_THET8 One of the primary rRNA binding proteins, it binds directly to 16S rRNA where it helps nucleate assembly of the body and platform of the 30S subunit. Binds mRNA in the 70S ribosome, positioning it for translation.[HAMAP-Rule:MF_01306_B] Publication Abstract from PubMedDuring normal translation, the binding of a release factor to one of the three stop codons (UGA, UAA or UAG) results in the termination of protein synthesis. However, modification of the initial uridine to a pseudouridine (Psi) allows efficient recognition and read-through of these stop codons by a transfer RNA (tRNA), although it requires the formation of two normally forbidden purine-purine base pairs. Here we determined the crystal structure at 3.1 A resolution of the 30S ribosomal subunit in complex with the anticodon stem loop of tRNASer bound to the PsiAG stop codon in the A site. The PsiA base pair at the first position is accompanied by the formation of purine-purine base pairs at the second and third positions of the codon, which show an unusual Watson-Crick/Hoogsteen geometry. The structure shows a previously unsuspected ability of the ribosomal decoding centre to accommodate non-canonical base pairs. Unusual base pairing during the decoding of a stop codon by the ribosome.,Fernandez IS, Ng CL, Kelley AC, Wu G, Yu YT, Ramakrishnan V Nature. 2013 Jun 30. doi: 10.1038/nature12302. PMID:23812587[1] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See AlsoReferences
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