ฉันรักแปลThe actual modification of the nucleotide, i.e. conversion of uridine to psedouridine and methylation of a ribose at the 2’-O position requires enzymes which recognise the snoRNA-rRNA complex. The snoRNAs can roughly be divided into two classes depending on their content of one of the two conserved structural elements known as the C/D and H/ACA boxes. All snoRNAs that direct 2’-O-methylation belong to the box C/D class while the snoRNAs that direct pseudouridylation are members of the H/ACA box family.