2I13 : Aart, a six finger zinc finger designed to recognize ANN triplets

  • Carlos F. Barbas (Contributor)
  • David J. Segal (Contributor)
  • Justin W. Crotty (Contributor)
  • Mital S. Bhakta (Contributor)
  • Nancy C Horton (Contributor)



Experimental Technique/Method:X-RAY DIFFRACTION
Release Date:2006-10-03
Deposition Date:2006-08-12
Revision Date:2008-05-01#2011-07-13
Molecular Weight:71077.38
Macromolecule Type:Protein#DNA
Residue Count:468
Atom Site Count:4117

Cys2-His2 zinc fingers are one of the most common types of DNA-binding domains. Modifications to zinc-finger binding specificity have recently enabled custom DNA-binding proteins to be designed to a wide array of target sequences. We present here a 1.96 A structure of Aart, a designed six-zinc finger protein, bound to a consensus DNA target site. This is the first structure of a designed protein with six fingers, and was intended to provide insights into the unusual affinity and specificity characteristics of this protein. Most protein-DNA contacts were found to be consistent with expectations, while others were unanticipated or insufficient to explain specificity. Several were unexpectedly mediated by glycerol, water molecules or amino acid-base stacking interactions. These results challenge some conventional concepts of recognition, particularly the finding that triplets containing 5'A, C, or T are typically not specified by direct interaction with the amino acid in position 6 of the recognition helix.
Date made available2006

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