Vaccinia virus DNA topoisomerase I preferentially removes positive supercoils from DNA

FEBS Lett. 1996 Apr 22;384(3):265-8. doi: 10.1016/0014-5793(96)00317-1.


Type I DNA topoisomerases homologous to Escherichia coli topoisomerase I normally only remove negative supercoils from DNA. Topoisomerases I from various eukaryotes share sequence homology and remove both positive and negative supercoils from DNA. Here we report that vaccinia virus topoisomerase I has significant difference in substrate preference from the other homologous type I topoisomerases. Vaccinia virus topoisomerase I shows a definite preference for removal of positive supercoils. In contrast, topoisomerase I from human, wheat germ and Saccharomyces cerevisiae has little preference between positive and negative supercoils. The vaccinia enzyme may have evolved for functions required for optimal viral growth. topoisomerases.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • DNA Topoisomerases, Type I / metabolism*
  • DNA, Bacterial / chemistry
  • DNA, Bacterial / metabolism
  • DNA, Superhelical / chemistry*
  • DNA, Superhelical / metabolism*
  • Escherichia coli / genetics
  • Models, Biological
  • Novobiocin / pharmacology
  • Nucleic Acid Conformation
  • Plasmids / genetics
  • Plasmids / metabolism
  • Promoter Regions, Genetic
  • Saccharomyces cerevisiae / enzymology
  • Substrate Specificity
  • Transcription, Genetic
  • Triticum / enzymology
  • Vaccinia virus / enzymology*
  • Vaccinia virus / genetics


  • DNA, Bacterial
  • DNA, Superhelical
  • Novobiocin
  • DNA Topoisomerases, Type I