Background：

The protein encoded by this gene is one subunit of a trimeric complex， forming a highly conserved transcription factor that binds with high specificity to CCAAT motifs in the promoter regions in a variety of genes. This gene product， subunit B， forms a tight dimer with the C subunit， a prerequisite for subunit A association. The resulting trimer binds to DNA with high specificity and affinity. Subunits B and C each contain a histone-like motif. Observation of the histone nature of these subunits is supported by two types of evidence; protein sequence alignments and experiments with mutants.