Identification of the breakage-reunion subunit of T4 DNA topoisomerase

J Biol Chem. 1984 Jul 25;259(14):9177-81.


The antitumor drug 4'-(9-acridinylamino)methanesulfon-m-anisidide which stimulates the cleavable complex formation between mammalian DNA topoisomerase II and DNA also stimulates the cleavable complex formation between bacteriophage T4-induced DNA topoisomerase and DNA. In the presence of 4'-(9-acridinylamino)methanesulfon-m-anisidide, T4 DNA topoisomerase and DNA form a "cleavable complex" which is characterized by its sensitivity to protein-denaturant treatment. Upon protein-denaturant treatment, the phosphodiester bond of DNA is cleaved, and the gene 52 protein subunit of the topoisomerase becomes covalently linked to the 5'-end of the broken DNA. The covalent protein-DNA linkage has been determined by both paper electrophoresis and thin layer chromatography to be tyrosyl phosphate.

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*
  • Escherichia coli / enzymology*
  • Kinetics
  • Macromolecular Substances
  • Plasmids
  • Protein Binding
  • Protein Denaturation
  • T-Phages / enzymology*


  • Macromolecular Substances
  • DNA Topoisomerases, Type I