Coactivator CBP, KIX domain (IPR003101)

Short name: KIX_dom

Overlapping homologous superfamilies

Domain relationships



Transcriptional activators are believed to stimulate gene expression via protein-protein interactions with the basal machinery. The cAMP-regulated transcription factor CREB has been shown to stimulate target gene expression, in part by associating with the coactivator paralogues p300 and CREB binding protein (CBP). CBP and P300 bind to the Ser-133-phosphorylated kinase-inducible domain (KID) of CREB via a region of approximately 90 residues referred to as the KIX domain, which is highly conserved in CBP homologues from Caenorhabditis elegans and Drosophila melanogaster. In addition to CREB, the KIX domain of CBP also recognises the transactivation domains of other nuclear factors, including Myb, Jun, cubitus interruptus, and HTLV-1 virally encoded Tax protein. Thus the KIX domain appears to be a common docking site on CBP for many transcriptional activators. The KIX domain is found in association with other domains, such as the bromodomain, the ZZ-type zinc finger, or the TAZ-type zinc finger [PMID: 8552098, PMID: 9413984].

The KIX domain of CBP is composed of three mutually interacting alpha helices, designated alpha1, alpha2 and alpha3, and two short 3(10) helices G1 and G2, that together with the interconnecting loops define a compact structural domain with an extensive hydrophobic core. Helices alpha1 and alpha3 constitute the primary interacting surface for the phosphorylated KID domain (pKID), forming a hydrophobic patch on the protein surface that is large enough to accommodate up to 3 turns of an amphipathic alpha helix, designated alphaB, in pKID. A second alpha helix in pKID, referred to as alphaA, interacts with a different face of the alpha3 helix of KIX. The two helices of pKID are arranged at an angle of about 90 degree and essentially wrap around the alpha3 helix of KIX [PMID: 8552098, PMID: 9413984].

GO terms

Biological Process

GO:0006355 regulation of transcription, DNA-templated

Molecular Function

GO:0003712 transcription coregulator activity

Cellular Component

No terms assigned in this category.

Contributing signatures

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