U5 spliceosomal RNA

U5 snRNA is a small nuclear RNA (snRNA) that participates in RNA splicing as a component of the spliceosome. It forms the U5 snRNP (small nuclear ribonucleoprotein) by associating with several proteins including Prp8 - the largest and most conserved protein in the spliceosome, Brr2 - a helicase required for spliceosome activation, Snu114, and the 7 Sm proteins.^[1] U5 snRNA forms a coaxially-stacked series of helices that project into the active site of the spliceosome.^[2][3] Loop 1, which caps this series of helices, forms 4-5 base pairs with the 5'-exon during the two chemical reactions of splicing.^[4][5] This interaction appears to be especially important during step two of splicing, exon ligation.^[6]

U5 spliceosomal RNA
Predicted secondary structure and sequence conservation of U5
Identifiers
Symbol	U5
Rfam	RF00020
Other data
RNA type	Gene; snRNA; splicing
Domain	Eukaryota
GO	GO:0000351 GO:0000353 GO:0005682 GO:0046540
SO	SO:0000395
PDB structures	PDBe

Medical relevance

Specific heterozygous variants in RNU5B-1, a gene that encodes one of the functional homologs of U5 spliceosomal RNA in humans, cause an autosomal dominant Neurodevelopmental disorder with seizures and joint laxity (OMIM 621090) also called RNU5B-1 syndrome^[7].