title: Structure-Based Virtual Ligand Screening on the XRCC4/DNA Ligase IV Interface.
abstract: The association of DNA Ligase IV (Lig4) with XRCC4 is essential for repair of DNA double-strand breaks (DSBs) by Non-homologous end-joining (NHEJ) in humans. DSBs cytotoxicity is largely exploited in anticancer therapy. Thus, NHEJ is an attractive target for strategies aimed at increasing the sensitivity of tumors to clastogenic anticancer treatments. However the high affinity of the XRCC4/Lig4 interaction and the extended protein-protein interface make drug screening on this target particularly challenging. Here, we conducted a pioneering study aimed at interfering with XRCC4/Lig4 assembly. By Molecular Dynamics simulation using the crystal structure of the complex, we first delineated the Lig4 clamp domain as a limited suitable target. Then, we performed in silico screening of ~95,000 filtered molecules on this Lig4 subdomain. Hits were evaluated by Differential Scanning Fluorimetry, Saturation Transfer Difference-NMR spectroscopy and interaction assays with purified recombinant proteins. In this way we identified the first molecule able to prevent Lig4 binding to XRCC4 in vitro. This compound has a unique tripartite interaction with the Lig4 clamp domain that suggests a starting chemotype for rational design of analogous molecules with improved affinity.
authors.affiliation: Institut de Pharmacologie et de Biologie Structurale, Université de Toulouse, CNRS, UPS, France.|Equipe labellisée Ligue Nationale Contre le Cancer, France.
authors.forename: Grégory
authors.initials: G
authors.lastname: Menchon
authors.affiliation: Institut de Pharmacologie et de Biologie Structurale, Université de Toulouse, CNRS, UPS, France.|Equipe labellisée Ligue Nationale Contre le Cancer, France.
authors.forename: Oriane
authors.initials: O
authors.lastname: Bombarde
authors.affiliation: Institut de Pharmacologie et de Biologie Structurale, Université de Toulouse, CNRS, UPS, France.
authors.forename: Mansi
authors.initials: M
authors.lastname: Trivedi
authors.affiliation: Centre de Recherche en Cancérologie de Marseille, CNRS, UMR7258, Marseille, F-13009, France.|INSERM, U1068, Marseille, F-13009, France.|Institut Paoli-Calmettes, Marseille, F-13009, France.|Aix-Marseille Université, Marseille, F-13284, France.
authors.forename: Aurélie
authors.initials: A
authors.lastname: Négrel
authors.affiliation: Synthèse et physico-chimie de molécules d'intérêt biologique, Université de Toulouse, CNRS, France.
authors.forename: Cyril
authors.initials: C
authors.lastname: Inard
authors.affiliation: Synthèse et physico-chimie de molécules d'intérêt biologique, Université de Toulouse, CNRS, France.
authors.forename: Brigitte
authors.initials: B
authors.lastname: Giudetti
authors.affiliation: Synthèse et physico-chimie de molécules d'intérêt biologique, Université de Toulouse, CNRS, France.
authors.forename: Michel
authors.initials: M
authors.lastname: Baltas
authors.affiliation: Institut de Pharmacologie et de Biologie Structurale, Université de Toulouse, CNRS, UPS, France.
authors.forename: Alain
authors.initials: A
authors.lastname: Milon
authors.affiliation: Centre de Recherche en Cancérologie de Marseille, CNRS, UMR7258, Marseille, F-13009, France.|INSERM, U1068, Marseille, F-13009, France.|Institut Paoli-Calmettes, Marseille, F-13009, France.|Aix-Marseille Université, Marseille, F-13284, France.
authors.forename: Mauro
authors.initials: M
authors.lastname: Modesti
authors.affiliation: Institut de Pharmacologie et de Biologie Structurale, Université de Toulouse, CNRS, UPS, France.
authors.forename: Georges
authors.initials: G
authors.lastname: Czaplicki
authors.affiliation: Institut de Pharmacologie et de Biologie Structurale, Université de Toulouse, CNRS, UPS, France.|Equipe labellisée Ligue Nationale Contre le Cancer, France.
authors.forename: Patrick
authors.initials: P
authors.lastname: Calsou
mesh_terms: D001665:Binding Sites; D004247:DNA / Q000737:chemistry* / Q000378:metabolism; D053903:DNA Breaks, Double-Stranded; D000072481:DNA Ligase ATP / Q000737:chemistry* / Q000378:metabolism; D004260:DNA Repair; D004268:DNA-Binding Proteins / Q000737:chemistry* / Q000378:metabolism; D006801:Humans; D008024:Ligands; D008958:Models, Molecular; D008968:Molecular Conformation; D062105:Molecular Docking Simulation; D056004:Molecular Dynamics Simulation; D011485:Protein Binding; D054730:Protein Interaction Domains and Motifs; D015203:Reproducibility of Results; D013329:Structure-Activity Relationship
chemical_list: D004268:DNA-Binding Proteins; D008024:Ligands; C101467:XRCC4 protein, human; D004247:DNA; D000072481:DNA Ligase ATP