A DNA topoisomerase IB in Thaumarchaeota testifies for the presence of this enzyme in the last common ancestor of Archaea and Eucarya

Biol Direct. 2008 Dec 23;3:54. doi: 10.1186/1745-6150-3-54.

Abstract

DNA topoisomerase IB (TopoIB) was thought for a long time to be a eukaryotic specific enzyme. A shorter version was then found in viruses and later on in several bacteria, but not in archaea. Here, we show that a eukaryotic-like TopoIB is present in the recently sequenced genomes of two archaea of the newly proposed phylum Thaumarchaeota. Phylogenetic analyses suggest that a TopoIB was present in the last common ancestor of Archaea and Eucarya. This finding indicates that the last common ancestor of Archaea and Eucarya may have harboured a DNA genome.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Archaea / enzymology*
  • Bacteria / enzymology
  • DNA Topoisomerases, Type I / chemistry
  • DNA Topoisomerases, Type I / genetics*
  • Eukaryotic Cells / enzymology*
  • Likelihood Functions
  • Phylogeny*
  • Protein Structure, Tertiary
  • Sequence Alignment
  • Viruses / enzymology

Substances

  • DNA Topoisomerases, Type I