An intrinsic 5'-deoxyribose-5-phosphate lyase activity in DNA polymerase beta from Leishmania infantum supports a role in DNA repair

DNA Repair (Amst). 2006 Jan 5;5(1):89-101. doi: 10.1016/j.dnarep.2005.08.001. Epub 2005 Sep 19.


Leishmania infantum is a parasitic protozoan which infects humans. This paper reports the expression in Escherichia coli and purification of the L. infantum gene product (AF182167), as well as its characterization as a DNA polymerase beta (Polbeta)-like, template-dependent DNA repair enzyme, with a metal preference for Mn2+ over Mg2+. As is the case with mammalian Polbeta and DNA polymerase lambda (Pollambda), L. infantum DNA polymerase beta (Li Polbeta) prefers gapped-DNA substrates having a 5'-phosphate end, in agreement with its role in DNA repair reactions. Purified Li Polbeta also displayed a 5'-deoxyribose-5-phosphate (dRP) lyase activity, consistent with a beta-elimination mechanism. The concerted action of dRP lyase and DNA polymerization activities of Li Polbeta on a uracil-containing DNA suggests its participation in "single-nucleotide" base excision repair (BER). Analysis of Li Polbeta DNA polymerization activity at different stages of the L. infantum infective cycle supports a role for Li Polbeta in nuclear DNA repair after the oxidative damage occurring inside the macrophage.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acid Sequence
  • Animals
  • DNA Polymerase beta / genetics
  • DNA Polymerase beta / metabolism*
  • DNA Repair / physiology*
  • Gene Expression Regulation, Enzymologic
  • Inclusion Bodies / genetics
  • Leishmania infantum / enzymology*
  • Leishmania infantum / physiology
  • Magnesium / metabolism
  • Manganese / metabolism
  • Molecular Sequence Data
  • Phosphorus-Oxygen Lyases / metabolism*
  • Recombinant Proteins / genetics
  • Recombinant Proteins / isolation & purification
  • Recombinant Proteins / metabolism
  • Substrate Specificity


  • Recombinant Proteins
  • Manganese
  • 5'-deoxyribose phosphate lyase
  • DNA Polymerase beta
  • Phosphorus-Oxygen Lyases
  • Magnesium

Associated data

  • GENBANK/AF182167