Nomenclature of plasmid-mediated 16S rRNA methylases
responsible for panaminoglycoside resistance.
aureus synthesizes ribosomal methylase
, which is encoded by the erythromycin resistance gene or another methylases
However, its unique structure may serve in the future as a prototype for new molecules resistant to both NDM and methylases
Distribution of genes encoding erythromycin ribosomal methylases
and an erythromycin efflux pump in epidemiologically distinct groups of staphylococci.
In the first step of this cycle, the SAM-dependent methylases
that use SAM as a substrate produce S-adenosyl homocysteine as a product.
The resistance is via three related genes, ermA, ermB, and ermC, which produce methylases
that alter the targeted ribosome by methylating it.
induce the SOS DNA repair response in Escherichia coli.
The activity of endogenous methylases
in human placenta increased steadily with weeks of gestation, suggesting that increased formation of methyltransferases might occur during pregnancy (Paik et al.
24,25) Secondly, high-level macrolide resistance may result from modification of the drug target (ribosomal binding site) via erm(B) genes that encode 23S rRNA methylases
, and lead to cross-resistance to the ML[S.
Like other methylases
, Dam chemically coats DNA with clusters of atoms known as methyl groups.
aureus is usually caused either by ribosomal modification mediated by 23S rRNA methylases
encoded by erm genes, or by active efflux of the antimicrobial agent by an ATP-dependent pump encoded by msrA gene.
In that study, ~2-5% of CCGG sites were fully methylated, suggesting that nuclear methylases
enter a subset of the mitochondria.