RlmQ: a newly discovered rRNA modification enzyme bridging RNA modification and virulence traits in .

rRNA modifications play crucial roles in fine-tuning the delicate balance between translation speed and accuracy, yet the underlying mechanisms remain elusive. Comparative analyses of the rRNA 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, in responsible for the Gram-positive specific mG2601, which is not modified in (G2574). We also demonstrate the absence of methylation on C1989, equivalent to C1962, which is methylated at position 5 by the Gram-negative specific RlmI methyltransferase, a paralog of RlmQ. Both modifications ( mG2601 and mC1962) are situated within the same tRNA accommodation corridor, hinting at a potential shared function in translation. Inactivation of causes 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.