RlmQ: A Newly Discovered rRNA Modification Enzyme Bridging RNA Modification and Virulence Traits inStaphylococcus aureus

Abstract

ABSTRACTrRNA modifications play crucial roles in fine-tuning the delicate balance between translation speed and accuracy, yet the underlying mechanisms remain elusive. Comparative analysis of the ribosomal RNA modifications in taxonomically distant bacteria could help define their general as well as species-specific roles. In this study, we identified a new methyltransferase, RlmQ, inStaphylococcus aureusresponsible for the Gram-positive specific m7G2601, which is not modified inE. coli(G2574). We also demonstrate the absence of methylation on C1989, equivalent toE. coliC1962, which is methylated at position 5 by the Gram-negative specific RlmI methyltransferase, a paralogue of RlmQ. Both modifications (S. aureusm7G2601 andE. colim5C1962) are situated within the same tRNA accommodation corridor, hinting at a potential shared function in translation. Inactivation ofS. aureus rlmQcauses the loss of methylation at G2601 and significantly impacts growth, cytotoxicity, and biofilm formation. These findings unravel the intricate connections between rRNA modifications, translation, and virulence in pathogenic Gram-positive bacteria.