TRNA (guanine¹⁰-N²)-dimethyltransferase (EC 2.1.1.213, PAB1283, N(2),N(2)-dimethylguanosine tRNA methyltransferase, Trm-G10, PabTrm-G10, PabTrm-m2 2G10 enzyme) is an enzyme with systematic name S-adenosyl-L-methionine:tRNA (guanine¹⁰-N²)-dimethyltransferase.^[1] This enzyme catalyses the following chemical reaction

2 S-adenosyl-L-methionine + guanine¹⁰ in tRNA ${\displaystyle \rightleftharpoons }$ 2 S-adenosyl-L-homocysteine + N²-dimethylguanine¹⁰ in tRNA (overall reaction)

(1a) S-adenosyl-L-methionine + guanine¹⁰ in tRNA ${\displaystyle \rightleftharpoons }$ S-adenosyl-L-homocysteine + N²-methylguanine¹⁰ in tRNA

(1b) S-adenosyl-L-methionine + N²-methylguanine¹⁰ in tRNA ${\displaystyle \rightleftharpoons }$ S-adenosyl-L-homocysteine + N²-dimethylguanine¹⁰ in tRNA