A novel active DNA topoisomerase I in Leishmania donovani

J Biol Chem. 2003 Feb 7;278(6):3521-6. doi: 10.1074/jbc.M203991200. Epub 2002 Nov 19.


A common feature shared by type I DNA topoisomerases is the presence of a "serine, lysine, X, X, tyrosine" motif as conventional enzyme active site. Preliminary data have shown that Leishmania donovani DNA topoisomerase I gene (LdTOP1A) lacked this conserved motif, giving rise to different theories about the reconstitution of an active DNA topoisomerase I in this parasite. We, herein, describe the molecular cloning of a new DNA topoisomerase I gene from L. donovani (LdTOP1B) containing the highly conserved serine, lysine, X, X, tyrosine motif. DNA topoisomerase I activity was detected only when both genes (LdTOP1A and LdTOP1B) were co-expressed in a yeast expression system, suggesting the existence of a dimeric DNA topoisomerase I in Leishmania parasites.

Publication types

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

MeSH terms

  • Amino Acid Motifs
  • Amino Acid Sequence
  • Animals
  • Base Sequence
  • Cloning, Molecular
  • DNA Primers
  • DNA Topoisomerases, Type I / chemistry
  • DNA Topoisomerases, Type I / genetics
  • DNA Topoisomerases, Type I / metabolism*
  • Genes, Protozoan
  • Humans
  • Leishmania donovani / enzymology*
  • Molecular Sequence Data
  • Open Reading Frames
  • Sequence Homology, Amino Acid


  • DNA Primers
  • DNA Topoisomerases, Type I

Associated data

  • GENBANK/AF303577