Structure and partial amino acid sequence of calf thymus DNA topoisomerase II: comparison with other type II enzymes

Biochem Biophys Res Commun. 1990 Jul 31;170(2):763-8. doi: 10.1016/0006-291x(90)92156-t.


The partial amino acid sequence of p140 calf thymus DNA topoisomerase II was determined by analysis of cyanogen bromide peptides. Five peptides were aligned and shared extensive homology with sequences derived from cDNA clones for the human topoisomerase II isoenzyme forms. Less homology was seen with the Drosophila, yeast and bacterial type II enzymes. Calf and human enzymes shared epitopes allowing isolation of a cDNA clone to human topoisomerase II isoenzyme alpha. Our results indicate that calf thymus p140 topoisomerase II is an active N-terminal proteolytic fragment of the native p180 enzyme and demonstrate that mammalian type II enzymes exhibit close sequence similarity.

Publication types

  • Comparative Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acid Sequence
  • Animals
  • Cattle
  • DNA Topoisomerases, Type II* / analysis
  • DNA Topoisomerases, Type II* / immunology
  • Drosophila / enzymology
  • Epitopes / immunology
  • Humans
  • Molecular Sequence Data
  • Molecular Weight
  • Saccharomyces / enzymology
  • Thymus Gland / enzymology*
  • Thymus Gland / immunology


  • Epitopes
  • DNA Topoisomerases, Type II