|PROSITE documentation PDOC50097
BTB domain profile
The BTB domain (Broad-Complex, Tramtrack and Bric a brac) is also known as the
POZ domain (POxvirus and Zinc finger). It is a homodimerization domain
occurring at the N-terminus of proteins containing multiple copies of either
zinc fingers of the C2H2 type (see <PDOC00028>) or Kelch repeats [1,2].
Many BTB proteins are transcriptional regulators that are thought to act
through the control of chromatin structure.
The structure of the BTB domain of the promyelocytic leukemia zinc finger
(PLZF) protein has been determined by X-ray crystallography and reveals a
tightly intertwined dimer with an extensive hydrophobic interface . A
surface-exposed groove lined with conserved amino acids is formed at the dimer
interface, suggesting a peptide-binding site.
Some proteins known to contain a BTB/TTK domain are listed below:
- Mammalian Bach proteins. These transcriptional regulators act as repressors
- Mammalian B-cell lymphoma 6 protein (BCL-6). A transcriptional regulator.
- Mammalian calicin. A possible morphogenic cytoskeletal element in
- Human promyelocytic leukemia zinc finger (PLZF). A probable transcription
- Drosophila GAGA transcription factor.
- Drosophila Mod(MDG4) or E(VAR)3-93D. A chromatin protein involved in gene
silencing in position effect variegation, the control of gypsy insulator
sequence, maintenance of gene expression, and apoptosis.
- Drosophila Tramtrack (TTK) protein. A probable transcriptional repressor.
- Drosophila Kelch protein. A component of ring canals that regulates the
flow of cytoplasm between cells.
- Vaccinia virus proteins A55, C2, C4, C13, and F3.
- Myxoma virus proteins M-T8 and M-T9.
December 2001 / First entry.
PROSITE method (with tools and information) covered by this documentation:
|BTB, PS50097; BTB domain profile (MATRIX)
|Sequences known to belong to this class detected by the profile:
|Other sequence(s) detected in Swiss-Prot:
|Matching PDB structures:
1BUO 1CS3 1R28 1R29 ... [ALL]
||Zollman S., Godt D., Prive G.G., Couderc J.L., Laski F.A.
||The BTB domain, found primarily in zinc finger proteins, defines an evolutionarily conserved family that includes several developmentally regulated genes in Drosophila.
||Proc. Natl. Acad. Sci. U.S.A. 91:10717-10721(1994).
||Bardwell V.J., Treisman R.
||The POZ domain: a conserved protein-protein interaction motif.
||Genes Dev. 8:1664-1677(1994).
||Ahmad K.F., Engel C.K., Prive G.G.
||Crystal structure of the BTB domain from PLZF.
||Proc. Natl. Acad. Sci. U.S.A. 95:12123-12128(1998).
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