It serves as a docking site for the formation of heterodimers between the coactivator and specific transcription factors.

The KIX domain was originally discovered in 1996 as the specific and minimal region in CBP that binds and interacts with phosphorylated CREB to activate transcription.

However, when it was later discovered that it also binds many other proteins, the more general name KIX domain became favoured.

Coactivators can associate with promoters and enhancers in the DNA only indirectly through protein-protein contacts with transcription factors.

GACKIX comprises structurally and functionally highly homologous domains in related proteins.