U1 small nuclear ribonucleoprotein A (SNRPA)

Component of the spliceosomal U1 snRNP, which is vital for recognition of the pre-mRNA 5' splice-site and the subsequent assembly of the spliceosome. U1 snRNP is the first snRNP to interact with pre-mRNA.

This interaction is necessary for the subsequent binding of U2 snRNP and the U4/U6/U5 tri-snRNP. SNRPA binds stem loop II of U1 snRNA.