smart01083

N-terminal domain of CBF1 interacting co-repressor CIR; This is a 45 residue conserved region at the N-terminal end of a family of proteins referred to as CIRs (CBF1-interacting co-repressors). 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.