InterPro domain: IPR031776
General Information
- Identifier IPR031776
- Description Splicing factor 3A subunit 3
- Number of genes 36
- Gene duplication stats Loading...
- Associated GO terms GO:0003723 GO:0005681 GO:0000398
Abstract
SF3A3 is a subunit of the SF3a splicing factor complex required for binding of the U2 snRNP to the pre-mRNA in an early step of spliceosome assembly [ 1 ]. Several SF3A3 homologues are also included in this entry , such as Prp9 from budding yeasts and Sap61 from fission yeasts.
In budding yeasts, SF3a complex shows a bifurcated assembly structure of three subunits, Prp9 (subunit 3), Prp11 (subunit 2) and Prp21 (subunit 1). Prp9 and Prp21 were not thought to interact with each other but the alpha1 helix of Prp9 does make important contacts with the SURP2 domain of Prp21, thus the two do interact via a bidentate-binding mode. Prp9 harbours a major binding site for stem-loop IIa of U2 snRNA [ 2 ].
1. Interactions between PRP9 and SPP91 splicing factors identify a protein complex required in prespliceosome assembly. Genes Dev. 7, 1390-9
2. Structure and assembly of the SF3a splicing factor complex of U2 snRNP. EMBO J. 31, 1579-90