tRNA (cytidine<sup>34</sup>-2'-O)-methyltransferase (, yibK (gene), methyltransferase yibK, TrmL, tRNA methyltransferase L, tRNA (cytidine<sup>34/5</sup>-carboxymethylaminomethyluridine<sup>34</sup>-2'-O)-methyltransferase) is an enzyme with systematic name S-adenosyl-L-methionine:tRNA (cytidine<sup>34/5</sup>-carboxymethylaminomethyluridine<sup>34</sup>-2'-O)-methyltransferase. This enzyme catalyses the following chemical reaction
The enzyme from Escherichia coli catalyses the 2'-O-methylation of cytidine or 5-carboxymethylaminomethyluridine at the wobble position at nucleotide 34 in tRNALeuCmAA and tRNALeucmnm5UmAA.