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

Céline Brochier-Armanet1*, Simonetta Gribaldo2 and Patrick Forterre2,3

Author Affiliations

1 Université de Provence, Aix-Marseille I, CNRS UPR9043, Laboratoire de Chimie Bactérienne, IFR88, Marseille, France

2 Institut Pasteur, 25 rue du Docteur roux, 75015 Paris, France

3 Univ Paris-sud, Institut de Génétique et Microbiologie, CNRS UMR8621, 91405 Orsay Cedex, France

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Biology Direct 2008, 3:54 doi:10.1186/1745-6150-3-54

Published: 23 December 2008

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.

Reviewer

This article was reviewed by Eugene Koonin and Anthony Poole