Acts as an activator of both rRNA/tRNA and protein methyltransferases. Together with methyltransferase mtq2, required for the methylation of eRF1 on 'Gln-182'. Together with methyltransferase trm11, required for the formation of 2-methylguanosine at position 10 (m2G10) in tRNA. Together with methyltransferase bud23, required for the formation of a 7-methylguanine in 18S rRNA. Involved in biogenesis of both 40S and 60S ribosomal subunits (By similarity). Heterodimer of mtq2-trm112, forming the eRF1 methyltransferase. Trm112 is necessary for the solubility and activity of the catalytic subunit mtq2. Interacts with trm11; required for full tRNA methyltransferase activity. Interacts with bud23; required for full rRNA methyltransferase activity. Interacts with rcm1, nop2, trm9 and lys9 (By similarity). Belongs to the TRM112 family.