The modification landscape ofP. aeruginosatRNAs

Abstract

RNA modifications have a substantial impact on tRNA function, with modifications in the anticodon loop contributing to translational fidelity and modifications in the tRNA core impacting structural stability. In bacteria, tRNA modifications are crucial for responding to stress and regulating the expression of virulence factors. Although tRNA modifications are well-characterized in a few model organisms, our knowledge of tRNA modifications in human pathogens, such asPseudomonas aeruginosa, remains limited. Here we leveraged two orthogonal approaches to build a reference landscape of tRNA modifications inE. coli, which enabled us to identify similar modifications inP. aeruginosa. Our analysis revealed a substantial degree of conservation between the two organisms, while also uncovering potential sites of tRNA modification in P. aeruginosa tRNAs that are not present inE. coli. The mutational signature at one of these sites, position 46 of tRNAGln1(UUG)is dependent on theP. aeruginosahomolog of TapT, the enzyme responsible for the 3-(3-amino-3-carboxypropyl) uridine (acp3U) modification. Identifying which modifications are present on different tRNAs will uncover the pathways impacted by the different tRNA modifying enzymes, some of which play roles in determining virulence and pathogenicity.