title: Mechanism of phage-induced lysis in pneumococci.
abstract: Earlier studies have suggested the possible role of host autolytic enzyme in the release of progeny phage from Dp-1 infected pneumococci. Several new experiments described here reinforce this notion. Specifically, the resistance of an autolysis-defective mutant to infection at low phage to cell ratios could be eliminated by prior 'coating' of the host bacteria with pneumococcal autolysin isolated from wild-type cells. Similar, productive infection was also possible by lowering the temperature of incubation to 30 degrees C, a condition that leads to a partial activation of the thermosensitive residual autolysin in the mutant cells. Other experiments, however, clearly indicate the role of the newly discovered phage-associated lysin (PAL), reported in the accompanying communication, in bacteriophage release and culture lysis; specifically, lysis was stimulated by reducing agents and inhibited by cardiolipin. It seems that both the host-related and the PAL activities are involved with Dp-1 induced lysis of pneumococci.
mesh_terms: D001433:Bacteriolysis / Q000187:drug effects; D001435:Bacteriophages / Q000201:enzymology / Q000502:physiology*; D002473:Cell Wall / Q000201:enzymology; D005467:Floxuridine / Q000494:pharmacology; D009154:Mutation; D009238:N-Acetylmuramoyl-L-alanine Amidase / Q000378:metabolism; D010400:Penicillin G / Q000494:pharmacology; D013296:Streptococcus pneumoniae / Q000187:drug effects / Q000201:enzymology / Q000502:physiology*; D013307:Streptomycin / Q000494:pharmacology
chemical_list: D005467:Floxuridine; D009238:N-Acetylmuramoyl-L-alanine Amidase; D010400:Penicillin G; D013307:Streptomycin