Host specificity of DNA produced by Escherichia coli. 9. Host-controlled modification of bacteriophage fd.

摘要: Host-controlled modification is shown to occur with four related male-specific bacteriophage strains containing single-stranded DNA: fd, f1, M13 and F12. All phages are restricted modified in bacteria B host specificity, the first three also P1-lysogenic cells. None of K specificity or carrying episome RTF-2. The bacterial characters rBmB which control λ DNA, responsible for restriction phage fd. apparent difference restriction, encountered by λ, but not thought find its explanation small molecular size fd on sites might be lacking. Indeed, act DNA fd: from infect restricting cells partially broken down acid-soluble products. On other hand, one-cycle growth fd.B non-restricting non-modifying Kr−m− yields, among a majority progeny fd.Kr−m− phage, some particles parental they have as density labelling infecting phage. efficiency such transfer was found 0.12 if measured after 18 minutes incubation infected implication this mechanism replication discussed.