U1 small nuclear ribonucleoprotein A/U2 small nuclear ribonucleoprotein B'' (IPR024888)

Short name: U1_snRNP_A/U2_snRNP_B''

Family relationships



The spliceosome is a complex of small nuclear RNA (snRNA) and protein subunits that catalyses the excision of introns and the ligation of exons to form a mature mRNA [PMID: 18854356]. Each spliceosome is composed of five snRNAs (U1, U2, U3, U4, U6), and a range of associated protein factors.

This entry represents U1 A and U2 B'', proteins that bind to the U1 and U2 snRNAs respectively. The U1 A protein binds to stem loop II of the U1 snRNA and is the first snRNP to interact with pre-mRNA. This interaction is the first step in canonical spliceosome assembly [PMID: 9848648]. The U2 B'' protein binds to stem loop IV of U2 snRNA only in presence of the U2A' protein [PMID: 9716128, PMID: 8649387].

GO terms

Biological Process

GO:0000398 mRNA splicing, via spliceosome

Molecular Function

GO:0017069 snRNA binding

Cellular Component

No terms assigned in this category.

Contributing signatures

Signatures from InterPro member databases are used to construct an entry.