1p7a
From Proteopedia
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Solution Stucture of the Third Zinc Finger from BKLF
Overview
Classical (CCHH) zinc fingers are among the most common protein domains, found in eukaryotes. They function as molecular recognition elements that, mediate specific contact with DNA, RNA, or other proteins and are composed, of a betabetaalpha fold surrounding a single zinc ion that is ligated by, two cysteine and two histidine residues. In a number of variant zinc, fingers, the final histidine is not conserved, and in other unrelated zinc, binding domains, residues such as aspartate can function as zinc ligands., To test whether the final histidine is required for normal folding and the, DNA-binding function of classical zinc fingers, we focused on finger 3 of, basic Kruppel-like factor. The structure of this domain was determined, using NMR spectroscopy and found to constitute a typical classical zinc, finger. We generated a panel of substitution mutants at the final, histidine in this finger and found that several of the mutants retained, some ability to fold in the presence of zinc. Consistent with this result, we showed that mutation of the final histidine had only a modest effect on, DNA binding in the context of the full three-finger DNA-binding domain of, basic Kruppel-like factor. Further, the zinc binding ability of one of the, point mutants was tested and found to be indistinguishable from the, wild-type domain. These results suggest that the final zinc chelating, histidine is not an essential feature of classical zinc fingers and have, implications for zinc finger evolution, regulation, and the design of, experiments testing the functional roles of these domains.
About this Structure
1P7A is a Single protein structure of sequence from Mus musculus with ZN as ligand. Full crystallographic information is available from OCA.
Reference
CCHX zinc finger derivatives retain the ability to bind Zn(II) and mediate protein-DNA interactions., Simpson RJ, Cram ED, Czolij R, Matthews JM, Crossley M, Mackay JP, J Biol Chem. 2003 Jul 25;278(30):28011-8. Epub 2003 May 7. PMID:12736264
Page seeded by OCA on Tue Nov 20 23:32:41 2007
