The BTB domain from human PLZF.
The BTB domain is a protein-protein interaction module consisting of approximately 120 amino acids found in over 600 different proteins from organisms ranging from yeast to humans. The domain was first identified as a conserved sequence element in the developmentally regulated Drosophila proteins Broad-complex, Tramtrack and Bric-abrac. The BTB domain, also known as the POZ (poxvirus and zinc finger) domain, is often found at the N-termini of several zinc finger transcription factors and Shaw-type potassium channel proteins. Experimental studies strongly implicate the BTB domain in regulating gene expression through the local control of chromatin conformation. In several cases, the BTB domain prevents high affinity DNA binding through control of protein oligomerization. Both homotypic and heterotypic protein-protein interactions have been observed as the BTB domain can form dimers as well as mediate interactions with non-BTB domain-containing proteins.
| BTB Domain Proteins | Binding Partners |
| Zinc Finger Protein with Interaction Domain (ZID) | Homotypic interaction |
| Zinc Finger 5 Protein (ZF5) | Homotypic interaction |
| BCL-6 Zinc Finger Transcription Repressor | N-CoR corepressor, SMRT corepressor |
| GAG Zinc Finger Protein | Tramtrack (T+k) via BTB heterotypic interaction |
