A tRNA modification with aminovaleramide facilitates AUA decoding in protein synthesis.

ABSTRACT: Modified tRNA anticodons are critical for proper mRNA translation during protein synthesis. It is generally thought that almost all bacterial tRNAs^Ile use a modified cytidine-lysidine (L)-at the first position (34) of the anticodon to decipher the AUA codon as isoleucine (Ile). Here we report that tRNAs^Ile from plant organelles and a subset of bacteria contain a new cytidine derivative, designated 2-aminovaleramididine (ava²C). Like L34, ava²C34 governs both Ile-charging ability and AUA decoding. Cryo-electron microscopy structural analyses revealed molecular details of codon recognition by ava²C34 with a specific interaction between its terminal amide group and an mRNA residue 3'-adjacent to the AUA codon. These findings reveal the ev

SUBMITTER: Miyauchi K 

PROVIDER: S-EPMC11938285 | biostudies-literature | 2025 Apr

REPOSITORIES: biostudies-literature