tRNA (guanine<sup>37</sup>-N<sup>1</sup>)-methyltransferase (, TrmD, tRNA (m1G37) methyltransferase, transfer RNA (m1G37) methyltransferase, Trm5p, TRMT5, tRNA-(N1G37) methyltransferase, MJ0883 (gene)) is an enzyme with systematic name S-adenosyl-L-methionine:tRNA (guanine<sup>37</sup>-N<sup>1</sup>)-methyltransferase. This enzyme catalyses the following chemical reaction
This enzyme is important for the maintenance of the correct reading frame during translation.