Cloning and characterization of the major AP endonuclease from Staphylococcus aureus
Turgimbayeva A. Zein U. Zharkov D.O. Ramankulov Y. Saparbaev M. Abeldenov S.
November 2022Elsevier B.V.
DNA Repair
2022#119
Apurinic/apyrimidinic (AP) endonucleases are key enzymes involved in the repair of abasic sites and DNA strand breaks. Complete genome analysis of Staphylococcus aureus identified a single AP endonuclease, SaNfo, which is a member of the endonuclease IV family exemplified by Escherichia coli Nfo. At present, it remains unknown whether SaNfo possesses DNA repair activities similar to its counterparts from E. coli and other bacteria. Here, we report that the purified SaNfo protein contains efficient AP endonuclease and nucleotide incision repair (NIR) activities. Optimal reaction conditions for SaNfo-catalysed AP endonuclease activity are high ionic strength and Mn2+ concentration, pH in range 7.5–9.0 and the temperature optimum of 37–45 °C. Cell-free extracts of S. aureus exhibited efficient AP site cleavage and NIR activities. Heterologous expression of SaNfo strongly reduces the sensitivity of AP endonuclease-deficient E. coli xth nfo strain to methylmethanesulfonate and H2O2. Site-directed mutagenesis showed that the Glu258 residue is critical for the SaNfo enzyme function. The AP endonuclease but not the NIR activity of SaNfo were stimulated by the β-clamp (SaDnaN dimer), suggesting that it might participate in the organization of BER in S. aureus. Overall, our data confirm that the activity, substrate specificity and in vivo functionality of S. aureus Nfo are consistent with this protein being the major AP endonuclease for the repair of DNA damage generated by endogenous and host-imposed factors.
Abasic sites , AP endonuclease , Base excision repair , DNA damage , DNA repair , Endonuclease IV , Nucleotide incision repair , Oxidative damage , Staphylococcus aureus
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National Center for Biotechnology, Nur-Sultan, 010000, Kazakhstan
L. N. Gumilyov Eurasian National University, Nur-Sultan, 010000, Kazakhstan
SB RAS Institute of Chemical Biology and Fundamental Medicine, Novosibirsk, 630090, Russian Federation
Novosibirsk State University, Novosibirsk, 630090, Russian Federation
School of Science and Humanities, Nazarbayev University, Qabanbay Batyr Ave 53, Nur-Sultan, 010000, Kazakhstan
Groupe Mechanisms of DNA Repair and Carcinogenesis, CNRS UMR9019, Université Paris-Saclay, Gustave Roussy Cancer Campus, Villejuif Cedex, F-94805, France
National Center for Biotechnology
L. N. Gumilyov Eurasian National University
SB RAS Institute of Chemical Biology and Fundamental Medicine
Novosibirsk State University
School of Science and Humanities
Groupe Mechanisms of DNA Repair and Carcinogenesis
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