This entry represents a 45 residue conserved domain found at the N-terminal end CIR protein (CBF1-interacting co-repressor, also known as corepressor interacting with RBPJ 1). This domain can be found in the fungal CWC25 family members and mammlian LENG1 (leukocyte receptor cluster member 1) protein.CBF1 (centromere-binding factor 1) acts as a transcription factor that causes repression by binding specifically to GTGGGAA motifs in responsive promoters, and it requires CIR as a co-repressor. CIR binds to histone deacetylase and to SAP30 and serves as a linker between CBF1 and the histone deacetylase complex []. CIR also plays a role in alternative splicing []. Budding yeast Cwc25 is a pre-mRNA-splicing factor involved in pre-mRNA splicing [].
