  2.1.1.B43 | S-adenosyl-L-methionine + cytosine49 in tRNA |
tRNAASp. In vitro, the purified recombinant methyltransferase catalyzes 5-methylcytosine formation at several cytosines within tRNAs with preference for C49. When tRNA is incubated with the PAB1947 enzyme at 50°C instead of 80°C, methylation becomes more specific for the 4751 sequence. Addition of archease to the methylation reactions with Pyrococcus abyssi tRNAAsp at 80°C increases modification within the oligonucleotide ACCCG that contains cytidine49, while reducing modification at unspecific sites. The unstructured poly(C)RNA is effectively methylated at 50°C, with most of the tritiated label from the methyl donor becoming incorporated into the RNA. However, when the recombinant PAB1947 enzyme is substituted with a Pyrococcus abyssi cell extract, no methylation of the poly(C) RNA occurs |
Pyrococcus abyssi |
S-adenosyl-L-homocysteine + 5-methylcytosine49 in tRNA |
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