Background
This gene encodes subunit 3 of the splicing factor 3b protein complex. Splicing factor 3b, together with splicing factor 3a and a 12S RNA unit, forms the U2 small nuclear ribonucleoproteins complex (U2 snRNP). The splicing factor 3b/3a complex binds pre-mRNA upstream of the intron's branch site in a sequence independent manner and may anchor the U2 snRNP to the pre-mRNA. Splicing factor 3b is also a component of the minor U12-type spliceosome. Subunit 3 has also been identified as a component of the STAGA (SPT3-TAF(II)31-GCN5L acetylase) transcription coactivator-HAT (histone acetyltransferase) complex, and the TFTC (TATA-binding-protein-free TAF(II)-containing complex). These complexes may function in chromatin modification, transcription, splicing, and DNA repair. [provided by RefSeq, Jul 2008],
Function
function:Subunit of the splicing factor SF3B required for 'A' complex assembly formed by the stable binding of U2 snRNP to the branchpoint sequence (BPS) in pre-mRNA. Sequence independent binding of SF3A/SF3B complex upstream of the branch site is essential, it may anchor U2 snRNP to the pre-mRNA. May also be involved in the assembly of the 'E' complex. Belongs also to the minor U12-dependent spliceosome, which is involved in the splicing of rare class of nuclear pre-mRNA intron.,similarity:Belongs to the RSE1 family.,subunit:Identified in the spliceosome C complex, at least composed of AQR, ASCC3L1, C19orf29, CDC40, CDC5L, CRNKL1, DDX23, DDX41, DDX48, DDX5, DGCR14, DHX35, DHX38, DHX8, EFTUD2, FRG1, GPATC1, HNRPA1, HNRPA2B1, HNRPA3, HNRPC, HNRPF, HNRPH1, HNRPK, HNRPM, HNRPR, HNRPU, KIAA1160, KIAA1604, LSM2, LSM3, MAGOH, MORG1, PABPC1, PLRG1, PNN, PPIE, PPIL1, PPIL3, PPWD1, PRPF19, PRPF4B
