Conserved Site

Transcription factor, NFYB/HAP3, conserved site (IPR003956)

Short name: Transcrpt_fac_NFYB/HAP3_CS


The CCAAT-binding factor (CBF) is a mammalian transcription factor that binds to a CCAAT motif in the promoters of a wide variety of genes, including type I collagen and albumin. The factor is a heteromeric complex of A and B subunits, both of which are required for DNA-binding [PMID: 2266139, PMID: 1549471]. The subunits can interact in the absence of DNA-binding, conserved regions in each being important in mediating this interaction.

The A subunit can be split into 3 domains on the basis of sequence similarity, a non-conserved N-terminal 'A domain'; a highly-conserved central 'B domain' involved in DNA-binding; and a C-terminal 'C domain', which contains a number of glutamine and acidic residues involved in protein-protein interactions [PMID: 1549471]. The A subunit shows striking similarity to the HAP3 subunit of the yeast CCAAT-binding heterotrimeric transcription factor [PMID: 1549471, PMID: 7845362]. The Kluyveromyces lactis HAP3 protein has been predicted to contain a 4-cysteine zinc finger, which is thought to be present in similar HAP3 and CBF subunit A proteins, in which the third cysteine is replaced by a serine [PMID: 7845362].

GO terms

Biological Process

GO:0006355 regulation of transcription, DNA-templated

Molecular Function

GO:0043565 sequence-specific DNA binding

Cellular Component

GO:0005634 nucleus

Contributing signatures

Signatures from InterPro member databases are used to construct an entry.
PROSITE patterns