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.

This molecular or cell biology article is a stub.