[brasarehot]

isn't it methyluridine, but what atom is methylated? Thanks.

[Arkcon]

It appears that is jargon for 5-methyluridine, which is another way of saying ribothymidine.

http://en.wikipedia.org/wiki/5-Methyluridine

I recognize that its a bit confusing sometimes, we're taught that thymidine pairs with adenine in DNA, uracil pairs for RNA.  But living things use a variety of modified bases for specialized needs.

http://pubs.acs.org/doi/abs/10.1021/bi00456a016

We generally (but not always) reserve the term "methylation" for adenine and cytidine residues.  Unless we're making cancer drugs.

http://en.wikipedia.org/wiki/DNA_methylation#In_mammals