Superinfection exclusion by P22 prophage in lysogens of Salmonella typhimurium. 1. Exclusion of generalized transducing particles.
نویسندگان
چکیده
P22-mediated generalized transduction in S. typhimwiwn occurs in both sensitive and lysogenic recipient bacteria, but the efficiency of transduction is significantly higherinsensitivecells t.han in wild-type P22 lysogens. This reduction in the efficiency of transduction is under the control of the prophage sieA gene; this gene is also responsible for the exclusion of superinfect,ing phage. Experiments with purified radioactive transducing particles demonstrate that exclusion of transducing particles in a sic+ lysogen occurs at some step after the adsorption of transducing particles to the cell. This exclusion can be partially overcome by infection of the sic+ lysogen with large numbers of nontransducing phage in addition to the purified transducing particles.
منابع مشابه
Superinfection exclusion by P22 prophage in lysogens of Salmonella typhimurium. II. Genetic evidence for two exclusion systems.
Mutants of the Salmonella phage P22 which, as prophages, do not prevent the growth of superinfecting virulent P22 phage were isolated. These mutants, called sieA-, retain some ability to exclude the heteroimmune phages L and MG178. Prophages carrying mutations at another locus, sieB, lose entirely the ability to exclude the heteroimmune phages. The sicmutants of Rao (1968) were shown to be sieA...
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عنوان ژورنال:
- Virology
دوره 45 3 شماره
صفحات -
تاریخ انتشار 1971