title: Zinc finger oxidation of Fpg/Nei DNA glycosylases by 2-thioxanthine: biochemical and X-ray structural characterization.
abstract: DNA glycosylases from the Fpg/Nei structural superfamily are base excision repair enzymes involved in the removal of a wide variety of mutagen and potentially lethal oxidized purines and pyrimidines. Although involved in genome stability, the recent discovery of synthetic lethal relationships between DNA glycosylases and other pathways highlights the potential of DNA glycosylase inhibitors for future medicinal chemistry development in cancer therapy. By combining biochemical and structural approaches, the physical target of 2-thioxanthine (2TX), an uncompetitive inhibitor of Fpg, was identified. 2TX interacts with the zinc finger (ZnF) DNA binding domain of the enzyme. This explains why the zincless hNEIL1 enzyme is resistant to 2TX. Crystal structures of the enzyme bound to DNA in the presence of 2TX demonstrate that the inhibitor chemically reacts with cysteine thiolates of ZnF and induces the loss of zinc. The molecular mechanism by which 2TX inhibits Fpg may be generalized to all prokaryote and eukaryote ZnF-containing Fpg/Nei-DNA glycosylases. Cell experiments show that 2TX can operate in cellulo on the human Fpg/Nei DNA glycosylases. The atomic elucidation of the determinants for the interaction of 2TX to Fpg provides the foundation for the future design and synthesis of new inhibitors with high efficiency and selectivity.
authors.affiliation: Centre de Biophysique Moléculaire, UPR4301, CNRS, rue Charles Sadron, 45100 Orléans cedex02, France Institute of Biochemistry and Biophysics PAS, Pawinskiego 5A, 02-106 Warsaw, Poland.
authors.forename: Artur
authors.initials: A
authors.lastname: Biela
authors.affiliation: Centre de Biophysique Moléculaire, UPR4301, CNRS, rue Charles Sadron, 45100 Orléans cedex02, France.
authors.forename: Franck
authors.initials: F
authors.lastname: Coste
authors.affiliation: Centre de Biophysique Moléculaire, UPR4301, CNRS, rue Charles Sadron, 45100 Orléans cedex02, France.
authors.forename: Françoise
authors.initials: F
authors.lastname: Culard
authors.affiliation: Centre de Biophysique Moléculaire, UPR4301, CNRS, rue Charles Sadron, 45100 Orléans cedex02, France.
authors.forename: Martine
authors.initials: M
authors.lastname: Guerin
authors.affiliation: Centre de Biophysique Moléculaire, UPR4301, CNRS, rue Charles Sadron, 45100 Orléans cedex02, France.
authors.forename: Stéphane
authors.initials: S
authors.lastname: Goffinont
authors.affiliation: Department of Chemistry, Ludwig-Maximilians-Universität (LMU), Butenandtstr. 5-13 (Haus F), München D-81377, Germany.
authors.forename: Karola
authors.initials: K
authors.lastname: Gasteiger
authors.affiliation: Institute of Biochemistry and Biophysics PAS, Pawinskiego 5A, 02-106 Warsaw, Poland.
authors.forename: Jarosław
authors.initials: J
authors.lastname: Cieśla
authors.affiliation: Institute of Biochemistry and Biophysics PAS, Pawinskiego 5A, 02-106 Warsaw, Poland.
authors.forename: Alicja
authors.initials: A
authors.lastname: Winczura
authors.affiliation: Institute of Chemistry, Warsaw University of Life Sciences, 159C Nowoursynowska St., 02-787 Warsaw, Poland.
authors.forename: Zygmunt
authors.initials: Z
authors.lastname: Kazimierczuk
authors.affiliation: Laboratoire Lésions des Acides Nucléiques, SCIB/UMR E3 CEA-UJF, INAC, CEA, Grenoble, France.
authors.forename: Didier
authors.initials: D
authors.lastname: Gasparutto
authors.affiliation: Department of Chemistry, Ludwig-Maximilians-Universität (LMU), Butenandtstr. 5-13 (Haus F), München D-81377, Germany.
authors.forename: Thomas
authors.initials: T
authors.lastname: Carell
authors.affiliation: Institute of Biochemistry and Biophysics PAS, Pawinskiego 5A, 02-106 Warsaw, Poland Institute of Genetics and Biotechnology, Warsaw University, Pawinskiego 5a, 02-106 Warsaw, Poland.
authors.forename: Barbara
authors.initials: B
authors.lastname: Tudek
authors.affiliation: Centre de Biophysique Moléculaire, UPR4301, CNRS, rue Charles Sadron, 45100 Orléans cedex02, France castaing@cnrs-orleans.fr.
authors.forename: Bertrand
authors.initials: B
authors.lastname: Castaing
mesh_terms: D018360:Crystallography, X-Ray; D004247:DNA / Q000378:metabolism; D045647:DNA Glycosylases / Q000037:antagonists & inhibitors* / Q000737:chemistry*; D043382:DNA-Formamidopyrimidine Glycosylase / Q000737:chemistry / Q000378:metabolism; D004791:Enzyme Inhibitors / Q000737:chemistry* / Q000494:pharmacology; D008958:Models, Molecular; D010084:Oxidation-Reduction; D013892:Thioxanthenes / Q000737:chemistry* / Q000494:pharmacology; D015032:Zinc / Q000378:metabolism; D016335:Zinc Fingers
chemical_list: D004791:Enzyme Inhibitors; D013892:Thioxanthenes; C060355:2-thioxanthene; D004247:DNA; D045647:DNA Glycosylases; D043382:DNA-Formamidopyrimidine Glycosylase; D015032:Zinc