SNAP annotations: PDB entry 1xmo

PDB-id

1xmo; DSSR-derived features in text and JSON formats; DNAproDB

Class

ribosome

Method

X-ray (3.25 Å)

Summary

Crystal structure of mnm5u34t6a37-trnalysuuu complexed with aag-mrna in the decoding center

Reference

Murphy FV, Ramakrishnan V, Malkiewicz A, Agris PF (2004): "The role of modifications in codon discrimination by tRNA(Lys)(UUU)." Nat.Struct.Mol.Biol., 11, 1186-1191. doi: 10.1038/nsmb861.

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.