SF3a Splicing Factor Complex

3D Model

SF3a is a eukaryotic complex located in the mature small nuclear ribonucleoprotein particle (U2 snRNP) and is essential for assembly of the spliceosome. This model was obtained from yeast (saccharomyces cerevisiae), but many key features have been evolutionarily conserved across species (including humans!).

SF3a is comprised of three distinct subunits – Prp9, Prp21 and Prp11. To interact with the rest of the spliceosomal machinery and promote its assembly, SF3a must bind to small nuclear RNA (U2 snRNA) – these molecules are essential components of U2 snRNP. Dissociation of SF3a from the spliceosome signals completion of assembly and initiates pre-mRNA splicing.

This tour details the protein-protein interactions between subunits that hold SF3a together, as well as experimental analyses that have been conducted to elucidate the mechanisms behind SF3a and U2 snRNA interactions.

https://www.embopress.org/doi/full/10.1038/emboj.2012.7#embj20127-bib-0009 https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1170906/