The BTB/POZ domain is a common
structural domain
In molecular biology, a protein domain is a region of a protein's polypeptide chain that is self-stabilizing and that folds independently from the rest. Each domain forms a compact folded three-dimensional structure. Many proteins consist of s ...
contained within some
protein
Proteins are large biomolecules and macromolecules that comprise one or more long chains of amino acid residues. Proteins perform a vast array of functions within organisms, including catalysing metabolic reactions, DNA replication, res ...
s.
The BTB (for BR-C, ttk and bab)
or POZ (for Pox virus and Zinc finger)
domain is present near the
N-terminus of a fraction of
zinc finger
A zinc finger is a small protein structural motif that is characterized by the coordination of one or more zinc ions (Zn2+) in order to stabilize the fold. It was originally coined to describe the finger-like appearance of a hypothesized struct ...
proteins and in proteins that contain the
Kelch motif and a family of pox virus proteins. The BTB/POZ domain mediates homomeric dimerisation and in some instances heteromeric dimerisation.
The structure of the dimerised PLZF BTB/POZ domain has been solved and consists of a tightly intertwined homodimer. The central scaffolding of the protein is made up of a cluster of alpha-helices flanked by short beta-sheets at both the top and bottom of the molecule.
BTB/POZ domains from several zinc finger proteins have been shown to mediate transcriptional repression and to interact with components of
histone deacetylase co-repressor complexes including
N-CoR and
SMRT.
The POZ or BTB domain is also known as BR-C/Ttk or ZiN.
References
{{DEFAULTSORT:BTB POZ domain
Protein domains