Vaccinia topoisomerase binds circumferentially to DNA Journal Article


Authors: Sekiguchi, J.; Shuman, S.
Article Title: Vaccinia topoisomerase binds circumferentially to DNA
Abstract: Vaccinia DNA topoisomerase, a member of the eukaryotic type I enzyme family, binds duplex DNA and forms a covalent adduct at sites containing a conserved sequence element 5'-CCCTT ↓ in the scissile strand. The protein- DNA interface entails essential contacts with four phosphate moieties within the CCCTT motif, including the scissile phosphate, and three phosphates within the GGGAA sequence on the noncleaved strand. Critical protein- phosphate contacts are arrayed across the minor groove of the DNA helix. Base-specific contacts with the pentamer element are within the major groove and are situated on the opposite face of the helix. Thus, vaccinia topoisomerase binds circumferentially to its target site in duplex DNA. This binding mode suggests that the eukaryotic enzyme adopts a toroidal shape in the DNA-bound state. Conformational isomerization of the bound protein provides a plausible mechanism for DNA relaxation.
Keywords: dna-binding proteins; nonhuman; pyrimidines; molecular sequence data; eukaryota; vaccinia virus; base sequence; binding site; models, molecular; nucleic acid conformation; dna binding; dna topoisomerase; dna topoisomerases, type i; protein dna interaction; enzyme conformation; vaccinia; priority journal; article; support, non-u.s. gov't; support, u.s. gov't, p.h.s.; macromolecular systems; deoxyribonucleoproteins
Journal Title: Journal of Biological Chemistry
Volume: 269
Issue: 50
ISSN: 0021-9258
Publisher: American Society for Biochemistry and Molecular Biology  
Date Published: 1994-12-16
Start Page: 31731
End Page: 31734
Language: English
PROVIDER: scopus
PUBMED: 7989346
DOI/URL:
Notes: Export Date: 14 January 2019 -- Article -- Source: Scopus
Citation Impact
MSK Authors
  1. Stewart H Shuman
    546 Shuman