A Mutation Study of the DNA Binding Domain of Human Papillomavirus Typell E2 Protein

Department of Molecular Biology, National Institute of Agrobiological Resources, Ibaraki.
Journal of Biochemistry (Impact Factor: 2.58). 02/1997; 121(1):138-44. DOI: 10.1093/oxfordjournals.jbchem.a021556
Source: PubMed


A site-specific mutation study was performed on the C-terminal domain, containing a cloned DNA binding region, of the human
papillomavirus typell (HPV11) E2 protein to determine the specific properties of residues directly involved in the DNA binding.
The effect of a point mutations on the DNA binding was assessed by means of a gel mobility shift assay. The mutagenesis was
concentrated on the residues in the third helix from the N-terminal, that is known as the“recognition helix,” in the crystal
structure of the bovine papillomavirus (BPV) E2 protein. Most point mutations caused a great decrease in the DNA binding activity.
The leucine repeat in the DNA binding region was proved not to be a leucine prerequisite, as the leucines could be substituted
by valine without significant loss of the DNA binding ability. Substitution of Leu for Glu caused a significant decrease in
the DNA binding, indicating that the hydrophobicity of the residue at this position is important. The results suggest that
the individual contribution of each amino acid residue in the DNA binding region is essential for the DNA binding.

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