Structural highlights
Function
[SNRPA_PIG] Component of the spliceosomal U1 snRNP, which is essential 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 required for the subsequent binding of U2 snRNP and the U4/U6/U5 tri-snRNP. SNRPA binds stem loop II of U1 snRNA. In a snRNP-free form (SF-A) may be involved in coupled pre-mRNA splicing and polyadenylation process. May bind preferentially to the 5'-UGCAC-3' motif on RNAs (By similarity).
Publication Abstract from PubMed
Human spliceosomal U1 small nuclear ribonucleoprotein particles (snRNPs), which consist of U1 small nuclear RNA and ten proteins, recognize the 5' splice site within precursor messenger RNAs and initiate the assembly of the spliceosome for intron excision. An electron density map of the functional core of U1 snRNP at 5.5 A resolution has enabled us to build the RNA and, in conjunction with site-specific labelling of individual proteins, to place the seven Sm proteins, U1-C and U1-70K into the map. Here we present the detailed structure of a spliceosomal snRNP, revealing a hierarchical network of intricate interactions between subunits. A striking feature is the amino (N)-terminal polypeptide of U1-70K, which extends over a distance of 180 A from its RNA binding domain, wraps around the core domain consisting of the seven Sm proteins and finally contacts U1-C, which is crucial for 5'-splice-site recognition. The structure of U1 snRNP provides insights into U1 snRNP assembly and suggests a possible mechanism of 5'-splice-site recognition.
Crystal structure of human spliceosomal U1 snRNP at 5.5 A resolution.,Pomeranz Krummel DA, Oubridge C, Leung AK, Li J, Nagai K Nature. 2009 Mar 26;458(7237):475-80. PMID:19325628[1]
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.
References
- ↑ Pomeranz Krummel DA, Oubridge C, Leung AK, Li J, Nagai K. Crystal structure of human spliceosomal U1 snRNP at 5.5 A resolution. Nature. 2009 Mar 26;458(7237):475-80. PMID:19325628 doi:10.1038/nature07851
