Coupling tRNAGly gene redundancy with staphylococcal cell wall integrity, antibiotic susceptibility and virulence potential

ABSTRACT: Redundancy in the number of tRNA genes which occur across species is poorly understood and, in many cases, remains essentially unexplored. In Staphylococcus aureus, several tRNAGly genes encode isoacceptors that either participate in protein synthesis or cell wall formation, upon aminoacylation by the sole glycyl-tRNA synthetase (GlyRS). Transcription of GlyRS, is regulated by a glyS T-box riboswitch in the 5’UTR, which responds to all tRNAGly isoacceptors and exhibits species-specific RNA conformations. To address whether disruption of the tRNAGly expression impacts the balance between ribosomal translation and cell wall formation, we used CRISPR/Cas9 editing to ablate one proteinogenic tRNAGly gene copy which is the strongest ligand of the glyS T-box riboswitch. Interestingly, no discernible impact on the growth and general translational activity of S. aureus was observed, suggesting that the remaining tRNAs could make up for this deficiency. However, transcriptomics and proteomics analyses revealed that the edited strain had deficient cell wall integrity, and subsequent experimentation showed increased susceptibility to antibiotics targeting the cell wall and resistance to lysostaphin. Interestingly, the observed alteration in the proteome level were independent of the glycine codon usage. Moreover, the edited strain exhibited reduced biofilm formation but retained its ability to invade human cell cultures. Overall, the present study highlights the important role of tRNA gene copy redundancy in the physiology of an important pathogen like S. aureus and consolidates the regulatory role of tRNAs in metabolic homeostasis.

ORGANISM(S): Staphylococcus aureus

PROVIDER: GSE285601 | GEO | 2025/07/16

REPOSITORIES: GEO