Small nuclear RNA

The small nuclear RNA (ARNpn), named for its small size by being in the nucleus of eukaryotic cells. It is also called U-RNA, due to its high uracil content. Like other RNAs, pRNA is single-stranded.

The pRNA binds to certain proteins of the nucleus forming the nuclear ribonucleoproteins, to carry out the process of intron removal (mRNA maturation).