SYNTHESIS AND MATURATION OF PHAGE P22 DNA .2. PROPERTIES OF TEMPERATURE-SENSITIVE PHAGE MUTANTS DEFECTIVE IN DNA METABOLISM

[摘要] Three temperature-sensitive mutants of phage P22 were isolated which are defective in phage DNA metabolism. After infection at restrictive temperature, 1 mutant (ts 12.1) falls to synthesize measurable quantities of phage DNA; nevertheless, parental phage DNA is recovered in a fast-sedimenting form similar to the 1st intermediate form observed after infection with normal phage. Another mutant (ts 5.1) synthesizes normal amounts of phage DNA, but neither this DNA nor parental DNA is converted from the 1st fast-sedimenting intermediate form into the 2nd, more slowly sedimentlng intermediate observed in normal infections. The 3rd mutant (ts 10.1), produces both intermediate forms in sequence, but fails to produce DNA having the sedimentation properties of mature phage DNA. None of the mutants encapsulates any DNA. The properties of these mutants are interpreted as supporting a scheme of sequential intermediates in P22 phage DNA synthesis and maturation.