Superinfection immunity of mycobacteriophage L5: applications for genetic transformation of mycobacteria

Mol Microbiol. 1993 Feb;7(3):407-17. doi: 10.1111/j.1365-2958.1993.tb01132.x.


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.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, Non-P.H.S.
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Amino Acid Sequence
  • Base Sequence
  • DNA Mutational Analysis
  • DNA, Bacterial / genetics
  • DNA, Recombinant / genetics
  • DNA-Binding Proteins / genetics*
  • Genes, Viral / genetics
  • Genetic Markers
  • Hot Temperature
  • Lysogeny / genetics*
  • Molecular Sequence Data
  • Mycobacteriaceae / genetics*
  • Mycobacteriophages / genetics*
  • Mycobacteriophages / growth & development
  • Phenotype
  • Plasmids / genetics
  • Restriction Mapping
  • Transformation, Genetic*
  • Viral Plaque Assay
  • Viral Proteins / genetics*


  • DNA, Bacterial
  • DNA, Recombinant
  • DNA-Binding Proteins
  • Genetic Markers
  • Viral Proteins
  • gp71 protein, Mycobacteriophage L5

Associated data

  • GENBANK/Z18946