Specifically methylates the guanine in position 2445 (m2G2445) and the guanine in position 2069 (m7G2069) of 23S rRNA. guanosine(2445) in 23S rRNA + S-adenosyl-L-methionine = H(+) + N(2)-methylguanosine(2445) in 23S rRNA + S-adenosyl-L-homocysteine guanosine(2069) in 23S rRNA + S-adenosyl-L-methionine = H(+) + N(2)-methylguanosine(2069) in 23S rRNA + S-adenosyl-L-homocysteine Belongs to the methyltransferase superfamily. RlmKL family. Extended N-terminus.