label: a 4-O-methyl-thymidine in DNA + L-cysteinyl-[protein] => a thymidine in DNA + S-methyl-L-cysteinyl-[protein]
label_lc: a 4-o-methyl-thymidine in dna + l-cysteinyl-[protein] => a thymidine in dna + s-methyl-l-cysteinyl-[protein]