This domain is found in eukaryotes. This domain is about 90 amino acids in length. This domain is found associated with PF00076. This domain is part of U1 snRNP, which is the pre-mRNA binding protein of the penta-snRNP spliceosome complex. It extends over a distance of 180 A from its RNA binding domain, wraps around the core domain of U1 snRNP consisting of the seven Sm proteins and finally contacts U1-C, which is crucial for 5'-splice-site recognition.
This domain is about 90 amino acids in length and is found at the N terminus of U1 small nuclear ribonucleoprotein 70 kDa (U1-70K), which is part of the U1 snRNP (snRNP) complex. U1 snRNP recognises the 5' splice site within precursor messenger RNAs and initiate the assembly of the spliceosome for intron excision.