preferred_name: a 5'-end dephospho-uridine-RNA + a 3'-end 2',3'-cyclophospho-ribonucleotide-RNA => ribonucleotidyl-uridine-RNA
preferred_name_lc: a 5'-end dephospho-uridine-rna + a 3'-end 2',3'-cyclophospho-ribonucleotide-rna => ribonucleotidyl-uridine-rna
label: a 5'-end dephospho-uridine-RNA + a 3'-end 2',3'-cyclophospho-ribonucleotide-RNA => ribonucleotidyl-uridine-RNA
label_lc: a 5'-end dephospho-uridine-rna + a 3'-end 2',3'-cyclophospho-ribonucleotide-rna => ribonucleotidyl-uridine-rna