Methylates eRF1 on 'Gln-182' using S-adenosyl L-methionine as methyl donor. eRF1 needs to be complexed to eRF3 in its GTP-bound form to be efficiently methylated. L-glutaminyl-[peptide chain release factor] + S-adenosyl-L-methionine = H(+) + N(5)-methyl-L-glutaminyl-[peptide chain release factor] + S-adenosyl-L-homocysteine Heterodimer of MTQ2-TRM112. MTQ2 is the catalytic subunit carrying the catalytic and the S-adenosyl L-methionine binding sites. Present with 3390 molecules/cell in log phase SD medium. Belongs to the eukaryotic/archaeal PrmC-related family.