Specifically methylates the N7 position of guanine in position 527 of 16S rRNA. Shows a marked preference for deproteinized 16S rRNA as substrate and is completely inactive with native 30S subunits as substrate. guanosine(527) in 16S rRNA + S-adenosyl-L-methionine = N(7)-methylguanosine(527) in 16S rRNA + S-adenosyl-L-homocysteine Low-level streptomycin resistance. Belongs to the methyltransferase superfamily. RNA methyltransferase RsmG family. Truncated N-terminus.