title: The phage growth limitation system in Streptomyces coelicolor A(3)2 is a toxin/antitoxin system, comprising enzymes with DNA methyltransferase, protein kinase and ATPase activity.
abstract: The phage growth limitation system of Streptomyces coelicolor A3(2) is an unusual bacteriophage defence mechanism. Progeny ϕC31 phage from an initial infection are thought to be modified such that subsequent infections are attenuated in a Pgl(+) host but normal in a Pgl(-) strain. Earlier work identified four genes required for phage resistance by Pgl. Here we demonstrate that Pgl is an elaborate and novel phage restriction system that, in part, comprises a toxin/antitoxin system where PglX, a DNA methyltransferase is toxic in the absence of a functional PglZ. In addition, the ATPase activity of PglY and a protein kinase activity in PglW are shown to be essential for phage resistance by Pgl. We conclude that on infection of a Pgl(+) cell by bacteriophage ϕC31, PglW transduces a signal, probably via phosphorylation, to other Pgl proteins resulting in the activation of the DNA methyltransferase, PglX and this leads to phage restriction.
authors.affiliation: Department of Molecular and Cell Biology, University of Aberdeen, Institute of Medical Science, Foresterhill, Aberdeen AB25 2ZD, UK.
authors.forename: Paul A
authors.initials: PA
authors.lastname: Hoskisson
authors.affiliation: Department of Genetics, University of Nottingham, Queens Medical Centre, Nottingham NG7 2UH, UK.
authors.forename: Paul
authors.initials: P
authors.lastname: Sumby
authors.affiliation: Department of Molecular and Cell Biology, University of Aberdeen, Institute of Medical Science, Foresterhill, Aberdeen AB25 2ZD, UK. Electronic address: maggie.smith@york.ac.uk.
authors.forename: Margaret C M
authors.initials: MCM
authors.lastname: Smith
mesh_terms: D000251:Adenosine Triphosphatases / Q000378:metabolism*; D001427:Bacterial Toxins / Q000378:metabolism*; D001435:Bacteriophages / Q000254:growth & development*; D004262:DNA Restriction Enzymes / Q000378:metabolism*; D004279:DNA, Viral / Q000378:metabolism; D006790:Host-Parasite Interactions; D011494:Protein Kinases / Q000378:metabolism*; D015398:Signal Transduction; D048372:Streptomyces coelicolor / Q000821:virology*
chemical_list: D001427:Bacterial Toxins; D004279:DNA, Viral; D011494:Protein Kinases; D004262:DNA Restriction Enzymes; D000251:Adenosine Triphosphatases
keywords: Bacteriophage; Defence; Immunity; Modification; Restriction; Streptomyces