What is the function of the leucine zipper?
The Leucine Zipper and the Basic DNA-Binding Domain (bZIP) This leucine zipper facilitates the dimerization of the protein by interdigitation of two leucine containing helices on different molecules and these residues form the buried subunit interface of the coiled-coil dimer.
How is the leucine zipper formed and what is its function?
The leucine zipper is formed by amphipathic interaction between two ZIP domains. When these alpha helices dimerize, the zipper is formed. The hydrophobic side of the helix forms a dimer with itself or another similar helix, burying the non-polar amino acids away from the solvent.
What is a homeodomain protein?
Homeodomain proteins are transcription factors that play major roles in many developmental processes of animals and plants by regulating the expression of other genes during development and differentiation, and are responsible for mating-type switching in yeast.
Why is it called a leucine zipper?
This class of DNA binding proteins gets its name from the regular pattern of leucine residues within the two alpha helices (pictured below on the right). Being hydrophobic, the leucines cause two adjacent alpha helices to be “zippered” together by hydrophobic interactions.
Why is leucine zipper stable?
The leucine zipper is a dimeric coiled-coil protein structure composed of two amphipathic alpha-helices with the hydrophobic surfaces interacting to create the dimer interface. Several workers have reported that amino acids in the e and g positions of the coiled coil can modulate dimerization stability and specificity.
What does a homeodomain do?
Homeodomains function as DNA binding domains and are found in many transcription factors that control development and cell fate decisions. Structurally, homeodomains are related to helix‐turn‐helix proteins of bacteria and consist of three α helices folded around a hydrophobic core and a flexible N‐terminal arm.
What is the significance of the homeodomain?
What is the significance of the homeodomain? The homeodomain is a highly conserved protein of 60 amino acids found in a variety of organisms, which, in conjunction with other factors, is thought to play a role in DNA binding and transcriptional activation.
Why is a leucine zipper called a zipper?
Where are zinc fingers found?
The canonical members of this class contain a binuclear zinc cluster in which two zinc ions are bound by six cysteine residues. These zinc fingers can be found in several transcription factors including the yeast Gal4 protein.
What is the role of homeodomain and Hom C?
Homeodomain‐containing proteins are often referred to as homeoproteins. Homeotic transformations cause one body segment to adopt the identity of another segment. Some homeobox genes are found in clusters, termed HOM‐C in insects and nematodes and HOX in mammals.
What is the homeodomain family?
The homeobox gene family is a large and diverse one, playing a fundamental role in metazoan development. Homeodomain proteins regulate diverse developmental programs by modulating expression patterns of target genes in a temporal, spatial and tissue-specific manner (3).
