InterPro domain: IPR013170

The cwf21 domain is found in proteins involved in mRNA splicing. Proteins containing this domain have been isolated as a subcomplex of the splicosome in Schizosaccharomyces pombe (Fission yeast) [ 1 ]. In yeast, this domain binds the protein Prp8p [ 2 ], a large and highly conserved U5 snRNP protein which has been proposed as a protein cofactor at the spliceosomal catalytic centre [ 3 ].

The cwf21 domain is found in, amongst others, the small Cwc21p protein in yeast as well as in the much larger human ortholog SRm300 (serine/arginine repetitive matrix protein).

1. Proteomics analysis reveals stable multiprotein complexes in both fission and budding yeasts containing Myb-related Cdc5p/Cef1p, novel pre-mRNA splicing factors, and snRNAs. Mol. Cell. Biol. 22, 2011-24
2. Physical and genetic interactions of yeast Cwc21p, an ortholog of human SRm300/SRRM2, suggest a role at the catalytic center of the spliceosome. RNA 15, 2161-73
3. The question remains: is the spliceosome a ribozyme? Nat. Struct. Biol. 7, 850-4