TRNA (adenine<sup>22</sup>-N<sup>1</sup>)-methyltransferase (, TrmK, YqfN, Sp1610 (gene), tRNA: m1A22 methyltransferase) is an enzyme with systematic name S-adenosyl-L-methionine:tRNA (adenine<sup>22</sup>-N<sup>1</sup>)-methyltransferase. This enzyme catalyses the following chemical reaction
The enzyme specifically methylates adenine<sup>22</sup> in tRNA.