The bZIP domain, also known as leucine zipper domain is a protein which is found in many eukaryotic DNA-binding proteins and is used for dimerization of proteins. The abbreviation stands for Basic leucine zipper domain, as a part of this region, many basic amino acids such as lysine and arginine.
A bZIP domain consists of an α -helix, wherein each seventh amino acid - often just a leucine - is hydrophobic. This is often referred to as Heptadenmuster.
If two of these domains from two proteins in contact, can form both homo-and hetero - dimers. The Leucine deposited in the hydrophilic environment due to hydrophobic interactions together. Since each subsequent Leucine is not 100% stand in a straight line, the two alpha helices wind to a left-handed super -helix (English coiled-coil ). At the DNA - binding region stops the twisting and forming a fork, the coiled-coil arms are slightly apart so that the frequently encountered here positively charged amino acids arginine and lysine bind to the negatively charged phosphate backbone of the DNA.
Proteins with bZIP domain
- AP-1 Fos / jun - a heterodimer that forms a transcription factor
- C / EBP - transcription factors
- Jun-B - transcription factor