• DOI:10.1073/pnas.111040498
• Corpus ID: 8176332

A type IB topoisomerase with DNA repair activities

@article{Belova2001ATI,
  title={A type IB topoisomerase with DNA repair activities},
  author={Galina I. Belova and Rajendra Prasad and Sergei A. Kozyavkin and James Alan Lake and S. H. Wilson and Alexei I. Slesarev},
  journal={Proceedings of the National Academy of Sciences of the United States of America},
  year={2001},
  volume={98},
  pages={6015 - 6020}
}

• G. I. Belova, R. Prasad, +3 authors A. Slesarev
• Published 15 May 2001
• Biology
• Proceedings of the National Academy of Sciences of the United States of America

Previously we have characterized type IB DNA topoisomerase V (topo V) in the hyperthermophile Methanopyrus kandleri. The enzyme has a powerful topoisomerase activity and is abundant in M. kandleri. Here we report two characterizations of topo V. First, we found that its N-terminal domain has sequence homology with both eukaryotic type IB topoisomerases and the integrase family of tyrosine recombinases. The C-terminal part of the sequence includes 12 repeats, each repeat consisting of two similar but distinct helix-hairpin-helix motifs; the same arrangement is seen in recombination protein RuvA and mammalian DNA polymerase β. Second, on the basis of sequence homology between topo V and polymerase β, we predict and demonstrate that topo V possesses apurinic/apyrimidinic (AP) site-processing activities that are important in base excision DNA repair: (i) it incises the phosphodiester backbone at the AP site, and (ii) at the AP endonuclease cleaved AP site, it removes the 5′ 2-deoxyribose 5-phosphate moiety so that a single-nucleotide gap with a 3′-hydroxyl and 5′-phosphate can be filled by a DNA polymerase. Topo V is thus the prototype for a new subfamily of type IB topoisomerases and is the first example of a topoisomerase with associated DNA repair activities.