title: Superinfection immunity of mycobacteriophage L5: applications for genetic transformation of mycobacteria.
abstract: Mycobacteriophage L5 is a temperate phage of the mycobacteria that forms stable lysogens in Mycobacterium smegmatis. We show here that the 183-amino-acid product of L5 gene 71 confers immunity to L5 superinfection, is required for maintenance of the lysogenic state and contains a helix-turn-helix DNA-binding motif--properties associated with repressors of temperate phages. We have utilized these observations to demonstrate the use of L5 gene 71 as a selectable marker for genetic transformation of the mycobacteria. Significantly, the use of L5 gene 71 as a selectable gene avoids the requirement for antibiotic-resistance genes providing an important tool for manipulation of the pathogens Mycobacterium tuberculosis and Mycobacterium avium, and for the construction of recombinant BCG vaccines.
authors.affiliation: Department of Biological Sciences, University of Pittsburgh, Pennsylvania 15260.
authors.forename: M K
authors.initials: MK
authors.lastname: Donnelly-Wu
authors.forename: W R
authors.initials: WR
authors.lastname: Jacobs
authors.forename: G F
authors.initials: GF
authors.lastname: Hatfull
mesh_terms: D000595:Amino Acid Sequence; D001483:Base Sequence; D004252:DNA Mutational Analysis; D004269:DNA, Bacterial / Q000235:genetics; D004274:DNA, Recombinant / Q000235:genetics; D004268:DNA-Binding Proteins / Q000235:genetics*; D005814:Genes, Viral / Q000235:genetics; D005819:Genetic Markers; D006358:Hot Temperature; D008242:Lysogeny / Q000235:genetics*; D008969:Molecular Sequence Data; D009159:Mycobacteriaceae / Q000235:genetics*; D009160:Mycobacteriophages / Q000235:genetics* / Q000254:growth & development; D010641:Phenotype; D010957:Plasmids / Q000235:genetics; D015183:Restriction Mapping; D014170:Transformation, Genetic; D010948:Viral Plaque Assay; D014764:Viral Proteins / Q000235:genetics*
chemical_list: D004269:DNA, Bacterial; D004274:DNA, Recombinant; D004268:DNA-Binding Proteins; D005819:Genetic Markers; D014764:Viral Proteins; C080483:gp71 protein, Mycobacteriophage L5