What are Zinc Finger Proteins (ZFPs)?

Function

ZFPs are found commonly in nature as a class of special transcription factors that bind to DNA, thus regulating gene expression. Zinc finger function was first studied using zinc finger protein Zif268.

Structure

ZFPs consist of smaller subunits called "fingers" which each contain a zinc finger binding helix that binds to unique DNA sequences. These fingers are linear and linked together by the "zinc finger backbone", a series of approximately 21 amino acids.

Terminology

• Backbone: contains most of the amino acids of a zinc finger protein: zif268 is the most famous backbone.
• Fingers: contain a backbone and a helix, bind to a 3-base DNA triplet
• Helix: the alpha helix in a finger. It is responsible for binding to a DNA triplet. Helices are made up of 7 amino acids, and fit into a specified position in a backbone. Amino acid positions are specified by -1,1,2,3,4,5, and 6.
• Zinc finger proteins (ZFPs): arrays of three fingers that bind to 9 bases (3 triplets) of DNA.

• Cis2His2 ZFPs have three main structural components:
  • Zinc finger binding helix
  • Linker region
  • Zinc ion that is coordinated by two cysteine residues and two histidine residues.

Helpful Zinc Finger Links

[http://en.wikipedia.org/wiki/Zinc_finger Zinc Fingers on Wikipedia]

• A more detailed introduction to zinc fingers.

[http://compbio.cs.princeton.edu/zf/ Predicting DNA Recognition by C2H2 Zinc Finger Proteins]

• A program useful for predicting how well a given amino acid sequence will bind to a given DNA sequence

[http://www.zincfingers.org/default2.htm The Zinc Finger Consortium]

• Information & helpful resources for zinc fingers

[http://www.jounglab.org/ Joung Lab]

• Information about Dr. Joung's extensive work with zinc fingers