Specifically methylates the N(7) position of guanine 1405 in 16S rRNA (By similarity). Confers resistance to various aminoglycosides, including kanamycin, tobramycin, amikacin, arbekacin, gentamicin, sisomicin and isepamicin. guanosine(1405) in 16S rRNA + S-adenosyl-L-methionine = N(7)-methylguanosine(1405) in 16S rRNA + S-adenosyl-L-homocysteine Belongs to the methyltransferase superfamily. Aminoglycoside resistance family.