Crystal structure of the E2 DNA-binding domain from human papillomavirus type 16: Implications for its DNA binding-site selection mechanism

Rashmi S. Hegde, Elliot J. Androphy

Research output: Contribution to journalArticle

78 Scopus citations

Abstract

The crystal structure of the E2 DNA-binding domain from the high-risk cervical cancer-associated strain human papillomavirus type 16 (HPV-16) is described here. The papillomavirus E2 proteins regulate transcription from all viral promoters and are required for the initiation of replication in vivo. They belong to a family of viral proteins that form dimeric β-barrels and use surface α-helices for DNA interaction. Although all E2 proteins recognize the same consensus, palindromic DNA sequence, proteins from different viral strains differ in their abilities to discriminate among their specific DNA-binding sites. The structure reported here reveals that while the overall fold of the HPV-16 E2 DNA-binding domain resembles that of its counterpart from the related viral strain bovine papillomavirus type 1, the precise placement of the recognition helices is significantly different. Additionally, the charge distribution on the DNA-binding surfaces of the two proteins varies; HPV-16 E2 has a much less electropositive surface. HPV-16 E2 is thus less able to utilize charge neutralization of the phosphate groups on DNA to induce bending. These results correlate well with previous solution studies that showed decreased affinity between HPV-16 E2 and flexible DNA target sequences, and enhanced affinity towards A-tract-containing, pre-bent sequences. In summary, the crystal structure of the HPV-16 E2 DNA-binding domain shows that the protein presents a stereo-chemically and electrostatically unique surface to DNA, characteristics that can contribute to its mechanism of DNA target discrimination.

Original languageEnglish (US)
Pages (from-to)1479-1489
Number of pages11
JournalJournal of molecular biology
Volume284
Issue number5
DOIs
StatePublished - Dec 18 1998
Externally publishedYes

Keywords

  • DNA binding
  • E2
  • Papillomavirus
  • X-ray crystallography
  • β-barrel

ASJC Scopus subject areas

  • Structural Biology
  • Molecular Biology

Fingerprint Dive into the research topics of 'Crystal structure of the E2 DNA-binding domain from human papillomavirus type 16: Implications for its DNA binding-site selection mechanism'. Together they form a unique fingerprint.

  • Cite this