RsmG is responsible for the synthesis of m7G535 (position 527 in E. coli) in the universally conserved loop of hairpin 18 in domain I. This modified nucleotide plays an essential role in binding antibiotics like streptomycin and kasugamycin. However the dependence on RsmG for antibiotic binding depends on the activity of RsmA (KsgA) catalyzing the formation of m6,6A1518,1519 at the 3'-end of 16S rRNA by RsmA (KsgA). In B. subtilis, mutations in both RsmA and RsmG allow better cell viability in the presence of antibiotics. AdoMet is the methyl group donor.