title: The role of modifications in codon discrimination by tRNA(Lys)UUU.
abstract: The natural modification of specific nucleosides in many tRNAs is essential during decoding of mRNA by the ribosome. For example, tRNA(Lys)(UUU) requires the modification N6-threonylcarbamoyladenosine at position 37 (t(6)A37), adjacent and 3' to the anticodon, to bind AAA in the A site of the ribosomal 30S subunit. Moreover, it can only bind both AAA and AAG lysine codons when doubly modified with t(6)A37 and either 5-methylaminomethyluridine or 2-thiouridine at the wobble position (mnm(5)U34 or s(2)U34). Here we report crystal structures of modified tRNA anticodon stem-loops bound to the 30S ribosomal subunit with lysine codons in the A site. These structures allow the rationalization of how modifications in the anticodon loop enable decoding of both lysine codons AAA and AAG.
authors.affiliation: Medical Research Council Laboratory of Molecular Biology, Hills Road, Cambridge CB2 2QH, UK.
authors.forename: Frank V
authors.initials: FV
authors.lastname: Murphy
authors.forename: Venki
authors.initials: V
authors.lastname: Ramakrishnan
authors.forename: Andrzej
authors.initials: A
authors.lastname: Malkiewicz
authors.forename: Paul F
authors.initials: PF
authors.lastname: Agris
mesh_terms: D000926:Anticodon / Q000737:chemistry / Q000378:metabolism; D020029:Base Pairing; D003062:Codon / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D018360:Crystallography, X-Ray; D008958:Models, Molecular; D009690:Nucleic Acid Conformation; D020871:RNA Stability; D012357:RNA, Transfer, Lys / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D016963:Thermus thermophilus / Q000737:chemistry / Q000235:genetics
chemical_list: D000926:Anticodon; D003062:Codon; D012357:RNA, Transfer, Lys