Specifically methylates the N7 position of guanine in position 527 of 16S rRNA. Requires the intact 30S subunit for methylation. guanosine(527) in 16S rRNA + S-adenosyl-L-methionine = N(7)-methylguanosine(527) in 16S rRNA + S-adenosyl-L-homocysteine Induced under stress conditions known to stimulate ppGpp accumulation and down-regulate rRNA synthesis. Low-level streptomycin resistance. Mechanisms acting on transcription regulation, translation or protein stability could be responsible for adjusting RsmG expression to rRNA synthesis. Belongs to the methyltransferase superfamily. RNA methyltransferase RsmG family.