Identification of essential amino acid residues of tRNA (Gm18)methyltransferase for methyl-transfer activity.
Recent computation analyses have pointed out an existence of conserved amino acid motifs among RNA ribose 2'-O-methyltransferases. However, the functions of these motifs are unclear yet. We carried out the site-directed mutagenesis studies systematically on Thermus thermophilus HB8 tRNA (Gm18) methyltransferase gene. Subsequent biochemical analyses with purified variant enzymes clearly revealed that five conserved amino acid residues (Asn35, Arg41, Glu124, Ser150, and Asn152) are involved in S-adenosyl-L-methionine binding. This is for the first time reporting the function of the conserved motifs among RNA ribose 2'-O-methyltransferases.
Watanabe
K
K
Department of Applied Chemistry, Faculty of Engineering, Ehime University, Matsuyama 790-8577, Japan.
Hori
H
H
Endo
Y
Y
D020816:Amino Acid Motifs; D000596:Amino Acids / Q000032:analysis; D001665:Binding Sites; D020134:Catalytic Domain; D008745:Methylation; D016415:Sequence Alignment; D016963:Thermus thermophilus / Q000201:enzymology; D012359:tRNA Methyltransferases / Q000737:chemistry*
D000596:Amino Acids; D012359:tRNA Methyltransferases; C023196:tRNA (guanine(10)-N(2))-dimethyltransferase