A Salmonella phage-P22 mutant defective in abortive transduction.
A Salmonella phage-P22 mutant defective in abortive transduction.
复制标题
沙门氏菌噬菌体 P22 突变体存在转导失败的缺陷。
DOI：
10.1093/genetics/145.1.17
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发表时间：
1997
期刊：
影响因子：
3.3
通讯作者：
Roth,J
中科院分区：
文献类型：
--
作者：
Benson,NR;Roth,J
在裂解性感染过程中，沙门氏菌噬菌体P22偶尔包裹细菌DNA而不是噬菌体DNA。因此，噬菌体裂解物包括两类病毒颗粒。携带细菌DNA的噬菌体颗粒被称为转导颗粒，并与携带噬菌体DNA的颗粒一样有效地将该DNA递送至宿主。一旦注射，转导的DNA可以与受体染色体重组以形成“完整的”转导子，或者它可以将自身建立为可表达的、非复制的遗传元件并形成“流产的”转导子。在这项工作中，我们描述了一个P22噬菌体突变体的能力降低，形成流产转导。负责这种表型的突变，calledtdx-1，被发现作为两个突变之一，有助于高转导表型的P22突变体HT 12/4。此外，tdx-1突变与aerf-1突变联合时是致命的。Tdx-1突变已被定位于P22基因组的一个区域，该区域编码几种注射蛋白，并可能涉及一个以上的突变位点。tdx-1突变的表型表明，Tdx蛋白通常有助于P22基因组的环化，也有助于形成被认为是失败转导所需的DNA环。
In the course of a lytic infection the Salmonella phage P22 occasionally encapsulates bacterial DNA instead of phage DNA. Thus, phage lysates include two classes of viral particles. Phage particles carrying bacterial DNA are referred to as transducing particles and deliver this DNA to a host as efficiently as particles carrying phage DNA. Once injected, the transduced DNA can either recombine with the recipient chromosome to form a “complete” transductant, or it can establish itself as an expressible, nonreplicating genetic element and form an “abortive” transductant. In this work, we describe a P22-phage mutant with reduced ability to form abortive transductants. The mutation responsible for this phenotype, calledtdx-1,was found as one of two mutations contributing to the high-transducing phenotype of the P22-mutant HT12/4. In addition, thetdx-1mutation is lethal when combined with anerf-ammutation. Thetdx-1mutation has been mapped to a region of the P22 genome that encodes several injected proteins and may involve more than one mutant locus. The phenotypes of thetdx-1mutation suggest that the Tdx protein(s) normally assist in the circularization of the P22 genome and also contribute to the formation of DNA circles thought to be required for abortive transduction.