- Zinc finger
A zinc finger is a large superfamily of
protein domains that can bind to DNA. A zinc finger consists of two antiparallelβ strands, and an α helix. The zincion is crucial for the stability of this domain type - in the absence of the metal ion the domain unfolds as it is too small to have a hydrophobic core.
One very well explored subset of zinc-fingers (the C2H2 class) comprises a pair of
cysteineresidues in the beta strands and two histidineresidues in the alpha helix which are responsible for binding a zinc ion. The two other classes of zinc finger proteins are the C4 and C6 classes. Zinc fingers are important in regulation because when interacted with DNA and zinc ion, they provide a unique structural motiffor DNA-binding proteins.
The structure of each individual finger is highly conserved and consists of about 30
amino acidresidues, constructed as a ββα fold and held together by the zinc ion. The α-helix occurs at the C-terminal part of the finger, while the β-sheet occurs at the N-terminal part.
consensus sequenceof a single finger is:Cys-X2-4-Cys-X3-Phe-X5-Leu-X2-His-X3-His
Proteins with Zinc finger
transcription factors (such as Zif268), regulatory proteins, and other proteins that interact with DNA contain zinc fingers. These proteins typically interact with the major groove along the double helixof DNA in which case the zinc fingers are arranged around the DNA strand in such a way that the α-helix of each finger contacts the DNA, forming an almost continuous stretch of α-helices around the DNA molecule.
Some primary neuron-specific transcriptional regulator that may be involved in mediating early neural development are also zinc finger-based.
The binding specificity for 3–4
base pairs is conferred by a short stretch of amino acid residues in the α-helix. The primary position of the amino acid residues within the α-helix interacting with the DNA are at positions -1, 3 and 6 relative to the first amino acid residueof the α-helix. Other amino acid positions can also influence binding specificity by assisting amino acid residues to bind a specific baseor by contacting a fourth base in the opposite strand, causing target-site overlap.
Zinc finger inhibitor
Steroid hormone receptor
last = Luscombe
first = Nicholas, "et al"
title = An overview of the structures of protein-DNA complexes
journal = Genome Biology Review
volume = 1
issue = 1
pages = 4–5
date = 9 June 2000
doi = 10.1186/gb-2000-1-1-reviews001
* [http://www.zincfingertools.org Zinc Finger Tools design and information site]
* [http://znf.llnl.gov/catalog/ Human KZNF Gene Catalog]
* [http://www.expasy.org/cgi-bin/nicedoc.pl?PDOC00028 Zinc finger C2H2-type domain] in
* [http://smart.embl-heidelberg.de/smart/do_annotation.pl?DOMAIN=ZnF_C2H2 Entry for zinc finger class C2H2 in the SMART database]
* [http://www.zincfingers.org The Zinc Finger Consortium]
* [http://bindr.gdcb.iastate.edu/ZiFiT/ ZiFiT- Zinc Finger Design Tool]
* [http://www.addgene.org/zfc Zinc Finger Consortium Materials from Addgene]
Wikimedia Foundation. 2010.
Look at other dictionaries:
zinc finger — n any of a class of proteins that typically possess tandem repeats of fingerlike loops of amino acids with each loop containing a zinc binding site at its base consisting of two molecules of cysteine and two molecules of histidine and that… … Medical dictionary
zinc finger — Zinc Finger Цинковый палец Одна из основных групп белков, связывающих ДНК. Являются регуляторами транскрипции, содержат характерный домен, который включает 2 цистеиновых и 2 гистидиновых остатков. Эти аминокислоты взаимодействуют с ионом… … Толковый англо-русский словарь по нанотехнологии. - М.
zinc finger — A motif associated with DNA binding proteins. A loop of 12 amino acids contains either 2 cysteine and 2 histidine groups (a cysteine histidine zinc finger), or 4 cysteines (a cysteine cysteine zinc finger), that directly coordinate a zinc atom.… … Dictionary of molecular biology
zinc finger — noun : any of a class of proteins that typically possess tandem repeats of fingerlike loops of amino acids with each loop containing a zinc binding site at its base consisting of two molecules of cysteine and two molecules of histidine and that… … Useful english dictionary
zinc finger — noun A structure, in some proteins, that binds to specific sequences of DNA and regulates genes … Wiktionary
zinc finger — A DNA binding protein motif, characterized by two closely spaced cysteine and two histidine residues that serve as ligands for a single Zn2+ ion. When bound, the structure takes on a conformation in which amino acid side chains protrude in a way… … Glossary of Biotechnology
Zinc finger nuclease — Zinc finger nucleases (ZFNs) are artificial restriction enzymes generated by fusing a zinc finger DNA binding domain to a DNA cleavage domain. Zinc finger domains can be engineered to target desired DNA sequences and this enables zinc finger… … Wikipedia
Zinc finger chimera — Zinc finger protein chimera are chimeric proteins composed of a DNA binding zinc finger protein domain and another domain through which the protein exerts its effect. The effector domain may be a transcriptional activator (A) or repressor… … Wikipedia
Zinc finger and BTB domain-containing protein 16 — Zinc finger and BTB domain containing 16, also known as ZBTB16, is a human gene. PBB Summary section title = summary text = This gene is a member of the Krueppel C2H2 type zinc finger protein family and encodes a zinc finger transcription factor… … Wikipedia
Zinc finger protein transcription factor — Zinc finger protein transcription factors or ZFP TFs, consisting of activators and repressors are transcription factors composed of a zinc finger protein domain (ZFP) and any of a variety of transcription factor effector domains which exert their … Wikipedia