[Genetic characteristics of a new phage resistance trait in Streptomyces coelicolor A3(2)].

Phage resistance was investigated in the system of Streptomyces coelicolor A3(2) and phi C31 actinophage. Resistance of A3(2) strain to phi C31 was shown to involve a novel mechanism responsible for the arrest of phage intracellular growth in the whole cell population. The phage resistance character designated Pgl+ (for "phage growth limiting") is determined by a gene located on the A3(2) chromosome.

[Plasmid SCP2 transfer by Streptomyces coelicolor A3(2) actinophages].

The ability of VP5 and phi c31 actinophages of Streptomyces coelicolor A3(2) to transfer plasmid SCP2 genes was tested. Infection with both phages led to formation of variants having the traits characteristics of plasmid bearing strains. The fertility properties of the variants suggested the presence of SCP2 in the autonomous state.

[Genetic mapping and characteristics of the actinophage phi C31 deletion mutants of Streptomyces coelicolor A3(2) incapable of lysogenization].

Actinophage phi C31 deletion c mutants with impaired ability to make repressor were genetically studied. Genetic crosses indicate that the c28 deletion mutant is situated with the c-region of the phi C31 genetic map. Based on the results of a qualitive test for recombination between several c mutants, a scheme of their order relative to deletion mutants was presented.

[Physical mapping of Streptomyces coelicolor A3(2) actinophage DNA. I. Location of the c-region of actinophage phiC31].

Mutants of temperate actinophage phi C31 Streptomyces coelicolor A3(2) having an increased resistance to chelating agents (sodium EDTA and sodium citrate) were isolated. Most of these mutants were not able to lysogenize sensitive cultures (c-mutants). DNA molecules of four c-mutants resistant to chelating agents were shown to be deleted by electron microscopy of DNA heteroduplexes.