title: The Role of the Exo-Xis Region in Oxidative Stress-Mediated Induction of Shiga Toxin-Converting Prophages.
abstract: Previous studies indicated that these genetic elements could be involved in the regulation of lysogenization and prophage induction processes. The effects were dramatic in Shiga toxin-converting phage Φ24(B) after treatment with oxidative stress-inducing agent, hydrogen peroxide, while they were less pronounced in bacteriophage λ and in both phages irradiated with UV. The hydrogen peroxide-caused prophage induction was found to be RecA-dependent. Importantly, in hydrogen peroxide-treated E. coli cells lysogenic for either λ or Φ24(B), deletion of the exo-xis region resulted in a significant decrease in the levels of expression of the S.O.S. regulon genes. Moreover, under these conditions, a dramatic decrease in the levels of expression of phage genes crucial for lytic development (particularly xis, exo, N, cro, O, Q, and R) could be observed in Φ24(B)-, but not in λ-bearing cells. We conclude that genes located in the exo-xis region are necessary for efficient expression of both host S.O.S regulon in lysogenic bacteria and regulatory genes of Shiga toxin-converting bacteriophage Φ24(B).
authors.affiliation: Department of Molecular Biology, University of Gdańsk, Wita Stwosza 59, 80-308 Gdańsk, Poland.
authors.forename: Katarzyna
authors.initials: K
authors.lastname: Licznerska
authors.affiliation: Department of Molecular Biology, University of Gdańsk, Wita Stwosza 59, 80-308 Gdańsk, Poland.
authors.forename: Aleksandra
authors.initials: A
authors.lastname: Dydecka
authors.affiliation: Department of Molecular Biology, University of Gdańsk, Wita Stwosza 59, 80-308 Gdańsk, Poland.
authors.forename: Sylwia
authors.initials: S
authors.lastname: Bloch
authors.affiliation: Department of Molecular Biology, University of Gdańsk, Wita Stwosza 59, 80-308 Gdańsk, Poland.
authors.forename: Gracja
authors.initials: G
authors.lastname: Topka
authors.affiliation: Department of Molecular Biology, University of Gdańsk, Wita Stwosza 59, 80-308 Gdańsk, Poland.
authors.forename: Bożena
authors.initials: B
authors.lastname: Nejman-Faleńczyk
authors.affiliation: Laboratory of Molecular Biology (Affiliated with the University of Gdańsk), Institute of Biochemistry and Biophysics, Polish Academy of Sciences, Wita Stwosza 59, 80-308 Gdańsk, Poland.
authors.forename: Alicja
authors.initials: A
authors.lastname: Węgrzyn
authors.affiliation: Department of Molecular Biology, University of Gdańsk, Wita Stwosza 59, 80-308 Gdańsk, Poland.
authors.forename: Grzegorz
authors.initials: G
authors.lastname: Węgrzyn
mesh_terms: D000595:Amino Acid Sequence; D001426:Bacterial Proteins / Q000737:chemistry / Q000378:metabolism; D010582:Bacteriophage lambda / Q000187:drug effects / Q000378:metabolism / Q000528:radiation effects; D004926:Escherichia coli / Q000187:drug effects / Q000235:genetics / Q000528:radiation effects; D015964:Gene Expression Regulation, Bacterial / Q000187:drug effects / Q000528:radiation effects; D006861:Hydrogen Peroxide / Q000494:pharmacology; D008242:Lysogeny / Q000187:drug effects / Q000528:radiation effects; D008969:Molecular Sequence Data; D018384:Oxidative Stress / Q000187:drug effects / Q000235:genetics* / Q000528:radiation effects; D016133:Polymerase Chain Reaction; D039002:Prophages / Q000187:drug effects / Q000378:metabolism* / Q000528:radiation effects; D011938:Rec A Recombinases / Q000378:metabolism; D012045:Regulatory Sequences, Nucleic Acid / Q000235:genetics*; D018085:Regulon / Q000235:genetics; D013014:SOS Response, Genetics / Q000187:drug effects / Q000235:genetics; D016415:Sequence Alignment; D012697:Serine Endopeptidases / Q000737:chemistry / Q000378:metabolism; D022621:Shiga Toxin / Q000378:metabolism*; D014466:Ultraviolet Rays; D014775:Virus Activation / Q000187:drug effects / Q000528:radiation effects; D000099160:LexA Repressor Protein
chemical_list: D001426:Bacterial Proteins; D006861:Hydrogen Peroxide; D011938:Rec A Recombinases; D012697:Serine Endopeptidases; D022621:Shiga Toxin; D000099160:LexA Repressor Protein