TopIb, a phylogenetic hallmark gene of Thaumarchaeota encodes a functional eukaryote-like topoisomerase IB.

ABSTRACT: Type IB DNA topoisomerases can eliminate torsional stresses produced during replication and transcription. These enzymes are found in all eukaryotes and a short version is present in some bacteria and viruses. Among prokaryotes, the long eukaryotic version is only observed in archaea of the phylum Thaumarchaeota. However, the activities and the roles of these topoisomerases have remained an open question. Here, we demonstrate that all available thaumarchaeal genomes contain a topoisomerase IB gene that defines a monophyletic group closely related to the eukaryotic enzymes. We show that the topIB gene is expressed in the model thaumarchaeon Nitrososphaera viennensis and we purified the recombinant enzyme from the uncultivated thaumarchaeon Candidatus Caldiarchaeum subterraneum. This enzyme

SUBMITTER: Dahmane N 

PROVIDER: S-EPMC4824112 | biostudies-literature | 2016 Apr

REPOSITORIES: biostudies-literature