Characterization of Streptococcal Bacteriophage c6A

Abstract

Bacteriophage c6A is a lytic phage that infects strains of Streptococcus lactis. Infection of S. lactis C6 under standard conditions yielded 124 ± 8 p.f.u. per infected cell after a latent period of 25 min at 30 °C. The virion of c6A was shown to contain at least 12 polypeptides and a 21.9 kilobase double-stranded, linear DNA genome with complementary 5′-protruding single-stranded termini. The (G + C) content of this DNA was estimated to be 36.7%. A restriction map was constructed which indicates that a number of restriction endonucleases did not digest the DNA and that others cleaved with a much lower frequency than expected.