Purification and characterization of tRNA(adenosine-1-)-methyltransferase from Thermus thermophilus HB27.

A58, the conserved adenosine residue in the T psi C loop of tRNAs, is methylated to m1A 58 in an extreme thermophile, Thermus thermophilus HB27. The enzyme catalyzing this methyltransfer reaction was purified from the thermophle. The substrate specificity of the enzyme was investigated by using tRNA fragments. The enzyme can transfer the methyl group to the 3'-half fragment of E. coli initiator tRNA, indicating that the main recognition site of the enzyme exists in the 3' half of tRNA including the T-loop and the T-stem.