title: Characterization of prophages containing "evolved" Dit/Tal modules in the genome of Lactobacillus casei BL23.
abstract: Lactic acid bacteria (LAB) have many applications in food and industrial fermentations. Prophage induction and generation of new virulent phages is a risk for the dairy industry. We identified three complete prophages (PLE1, PLE2, and PLE3) in the genome of the well-studied probiotic strain Lactobacillus casei BL23. All of them have mosaic architectures with homologous sequences to Streptococcus, Lactococcus, Lactobacillus, and Listeria phages or strains. Using a combination of quantitative real-time PCR, genomics, and proteomics, we showed that PLE2 and PLE3 can be induced-but with different kinetics-in the presence of mitomycin C, although PLE1 remains as a prophage. A structural analysis of the distal tail (Dit) and tail associated lysin (Tal) baseplate proteins of these prophages and other L. casei/paracasei phages and prophages provides evidence that carbohydrate-binding modules (CBM) located within these "evolved" proteins may replace receptor binding proteins (RBPs) present in other well-studied LAB phages. The detailed study of prophage induction in this prototype strain in combination with characterization of the proteins involved in host recognition will facilitate the design of new strategies for avoiding phage propagation in the dairy industry.
authors.affiliation: Departamento de Química Biológica, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, IQUIBICEN-CONICET, Buenos Aires, Argentina.
authors.forename: María Eugenia
authors.initials: ME
authors.lastname: Dieterle
authors.affiliation: Departamento de Química Biológica, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, IQUIBICEN-CONICET, Buenos Aires, Argentina.
authors.forename: Joaquina
authors.initials: J
authors.lastname: Fina Martin
authors.affiliation: Unidad de Bioquímica y Proteómica Analíticas, Institut Pasteur de Montevideo, Montevideo, Uruguay.
authors.forename: Rosario
authors.initials: R
authors.lastname: Durán
authors.affiliation: Departamento de Química Biológica, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, IQUIBICEN-CONICET, Buenos Aires, Argentina.
authors.forename: Sergio I
authors.initials: SI
authors.lastname: Nemirovsky
authors.affiliation: Departamento de Química Biológica, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, IQUIBICEN-CONICET, Buenos Aires, Argentina.
authors.forename: Carmen
authors.initials: C
authors.lastname: Sanchez Rivas
authors.affiliation: Department of Biological Sciences and Pittsburgh Bacteriophage Institute, University of Pittsburgh, Pittsburgh, USA.|Department of Integrative Structural and Computational Biology, The Scripps Research Institute, La Jolla, CA, USA.
authors.forename: Charles
authors.initials: C
authors.lastname: Bowman
authors.affiliation: Department of Biological Sciences and Pittsburgh Bacteriophage Institute, University of Pittsburgh, Pittsburgh, USA.
authors.forename: Daniel
authors.initials: D
authors.lastname: Russell
authors.affiliation: Department of Biological Sciences and Pittsburgh Bacteriophage Institute, University of Pittsburgh, Pittsburgh, USA.
authors.forename: Graham F
authors.initials: GF
authors.lastname: Hatfull
authors.affiliation: Architecture et Fonction des Macromolécules Biologiques, UMR 7257 Centre National de la Recherche Scientifique, Marseille, France.|Architecture et Fonction des Macromolécules Biologiques, UMR 7257 Aix-Marseille Université, Marseille, France.
authors.forename: Christian
authors.initials: C
authors.lastname: Cambillau
authors.affiliation: Departamento de Química Biológica, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, IQUIBICEN-CONICET, Buenos Aires, Argentina. mpiuri@qb.fcen.uba.ar.
authors.forename: Mariana
authors.identifier: http://orcid.org/0000-0001-9058-8247
authors.initials: M
authors.lastname: Piuri
mesh_terms: D005516:Food Microbiology; D007780:Lacticaseibacillus casei / Q000235:genetics* / Q000821:virology*; D016685:Mitomycin / Q000378:metabolism; D019384:Nucleic Acid Synthesis Inhibitors / Q000378:metabolism; D039002:Prophages / Q000235:genetics* / Q000502:physiology*; D017376:Viral Tail Proteins / Q000235:genetics; D014775:Virus Activation
chemical_list: D019384:Nucleic Acid Synthesis Inhibitors; D017376:Viral Tail Proteins; D016685:Mitomycin
keywords: Bacteriophage; Baseplate; Lactobacillus casei; Prophage