title: Defining the crucial domain and amino acid residues in bacterial Lon protease for DNA binding and processing of DNA-interacting substrates.
abstract: Lon protease previously has been shown to interact with DNA, but the role of this interaction for Lon proteolytic activity has not been characterized. In this study, we used truncatedEscherichia coliLon constructs, bioinformatics analysis, and site-directed mutagenesis to identify Lon domains and residues crucial for Lon binding with DNA and effects on Lon proteolytic activity. We found that deletion of Lon's ATPase domain abrogated interactions with DNA. Substitution of positively charged amino acids in this domain in full-length Lon with residues conferring a net negative charge disrupted binding of Lon to DNA. These changes also affected the degradation of nucleic acid-binding protein substrates of Lon, intracellular localization of Lon, and cell morphology.In vivotests revealed that Lon-DNA interactions are essential for Lon activity in cell division control. In summary, we demonstrate that the ability of Lon to bind DNA is determined by its ATPase domain, that this binding is required for processing protein substrates in nucleoprotein complexes, and that Lon may help regulate DNA replication in response to growth conditions.
authors.affiliation: From the Department of Molecular and Cellular Biology, Intercollegiate Faculty of Biotechnology, University of Gdansk, Abrahama 58, 80-307 Gdansk, Poland.
authors.forename: Anna
authors.initials: A
authors.lastname: Karlowicz
authors.affiliation: From the Department of Molecular and Cellular Biology, Intercollegiate Faculty of Biotechnology, University of Gdansk, Abrahama 58, 80-307 Gdansk, Poland.
authors.forename: Katarzyna
authors.initials: K
authors.lastname: Wegrzyn
authors.affiliation: From the Department of Molecular and Cellular Biology, Intercollegiate Faculty of Biotechnology, University of Gdansk, Abrahama 58, 80-307 Gdansk, Poland.
authors.forename: Marta
authors.initials: M
authors.lastname: Gross
authors.affiliation: From the Department of Molecular and Cellular Biology, Intercollegiate Faculty of Biotechnology, University of Gdansk, Abrahama 58, 80-307 Gdansk, Poland.
authors.forename: Dagmara
authors.initials: D
authors.lastname: Kaczynska
authors.affiliation: From the Department of Molecular and Cellular Biology, Intercollegiate Faculty of Biotechnology, University of Gdansk, Abrahama 58, 80-307 Gdansk, Poland.
authors.forename: Malgorzata
authors.initials: M
authors.lastname: Ropelewska
authors.affiliation: Laboratory of Bioinformatics and Protein Engineering, International Institute of Molecular and Cell Biology in Warsaw, Księcia Trojdena 4, 02-109 Warsaw, Poland, and.
authors.forename: Małgorzata
authors.initials: M
authors.lastname: Siemiątkowska
authors.affiliation: Laboratory of Bioinformatics and Protein Engineering, International Institute of Molecular and Cell Biology in Warsaw, Księcia Trojdena 4, 02-109 Warsaw, Poland, and.|Institute of Molecular Biology and Biotechnology, Adam Mickiewicz University, Umultowska 89, 61-614 Poznan, Poland.
authors.forename: Janusz M
authors.initials: JM
authors.lastname: Bujnicki
authors.affiliation: From the Department of Molecular and Cellular Biology, Intercollegiate Faculty of Biotechnology, University of Gdansk, Abrahama 58, 80-307 Gdansk, Poland, igor.konieczny@biotech.ug.edu.pl.
authors.forename: Igor
authors.initials: I
authors.lastname: Konieczny
mesh_terms: D000251:Adenosine Triphosphatases / Q000235:genetics / Q000378:metabolism*; D002455:Cell Division / Q000502:physiology; D004261:DNA Replication / Q000502:physiology*; D004269:DNA, Bacterial / Q000096:biosynthesis* / Q000235:genetics; D004268:DNA-Binding Proteins / Q000235:genetics / Q000378:metabolism*; D004926:Escherichia coli / Q000201:enzymology* / Q000235:genetics; D029968:Escherichia coli Proteins / Q000235:genetics / Q000378:metabolism*; D049070:Protease La / Q000235:genetics / Q000378:metabolism*; D000072417:Protein Domains
chemical_list: D004269:DNA, Bacterial; D004268:DNA-Binding Proteins; D029968:Escherichia coli Proteins; C483567:Lon protein, E coli; D049070:Protease La; D000251:Adenosine Triphosphatases
keywords: ATP-dependent protease; DNA-binding protein; Escherichia coli (E. coli); protein-DNA interaction; proteolysis