Distal Domains of the Bacterial-Exclusive Wobble-Modifying Enzyme TilS Contribute to Catalysis.

ABSTRACT: tRNA^Ile2 lysidine synthetase (TilS) is a bacterial-specific wobble-modifying enzyme that acts on the isoleucine-accepting tRNA^Ile2 _CAU. TilS installs a lysine at the C34 position of the anticodon, generating the lysidine modification. The resulting LAU anticodon enables exclusive decoding of infrequently used AUA isoleucine codons, rejecting AUG methionine codons. Compared to other wobble-modifying enzymes that contact only the anticodon arm of their cognate tRNAs, TilS is distinct in containing additional domains outside of the N-terminal active site. For type I TilS enzymes such as the B. cenocepacia TilS (BcTilS) investigated here, appended domains contact the tRNA^Ile2 substrate along the body and through the acceptor stem, up to 60 Å a

SUBMITTER: Guinto FC 

PROVIDER: S-EPMC11947777 | biostudies-literature | 2025 Mar

REPOSITORIES: biostudies-literature