Phenotypic characterization of temperature-sensitive mutants of vaccinia virus with mutations in a 135,000-Mr subunit of the virion-associated DNA-dependent RNA polymerase
Phenotypic characterization of temperature-sensitive mutants of vaccinia virus with mutations in a 135,000-Mr subunit of the virion-associated DNA-dependent RNA polymerase
复制标题
痘苗病毒温度敏感突变体的表型特征，其病毒粒子相关 DNA 依赖性 RNA 聚合酶的 135,000-Mr 亚基发生突变
作者：
M. Ensinger
三个温度敏感（TS）的突变体的牛痘病毒，其中的TS突变被映射到一个高分子量亚基的病毒体相关的DNA依赖的RNA聚合酶的基因的表型缺陷的特点。由于病毒体RNA聚合酶是启动病毒复制周期所必需的，因此已经预测这种类型的突变体在非允许温度下在病毒DNA复制和早期病毒蛋白质的合成中是有缺陷的。然而，所有三个突变体都合成了DNA和早期蛋白质，其中两个还合成了晚期蛋白质。透化突变体病毒体外合成RNA的能力并不比野生型强。此外，只有一个三RNA聚合酶的活动，部分纯化的病毒粒子组装在允许的温度下显示改变的生化特性，在体外可能与它的ts突变：ts 13活性降低比活性，增加温度敏感性，并增加热不稳定性在各种预孵育条件下。虽然部分纯化的聚合酶活性的第二个突变体，ts 72，也是更热不稳定性比野生型活性，热不稳定性被证明是第二个突变的结果内的RNA聚合酶基因。这些结果表明，这些突变体中的缺陷影响新合成的聚合酶亚基组装成活性酶或将RNA聚合酶掺入成熟的病毒体中;一旦在允许温度下合成，突变体聚合酶能够在非允许温度下启动随后几轮感染中发挥作用。
The phenotypic defects of three temperature-sensitive (ts) mutants of vaccinia virus, the ts mutations of which were mapped to the gene for one of the high-molecular-weight subunits of the virion-associated DNA-dependent RNA polymerase, were characterized. Because the virion RNA polymerase is required for the initiation of the viral replication cycle, it has been predicted that this type of mutant is defective in viral DNA replication and the synthesis of early viral proteins at the nonpermissive temperature. However, all three mutants synthesized both DNA and early proteins, and two of the three synthesized late proteins as well. RNA synthesis in vitro by permeabilized mutant virions was not more ts than that by the wild type. Furthermore, only one of three RNA polymerase activities that was partially purified from virions assembled at the permissive temperature displayed altered biochemical properties in vitro that could be correlated with its ts mutation: the ts13 activity had reduced specific activity, increased temperature sensitivity, and increased thermolability under a variety of preincubation conditions. Although the partially purified polymerase activity of a second mutant, ts72, was also more thermolabile than the wild-type activity, the thermolability was shown to be the result of a second mutation within the RNA polymerase gene. These results suggest that the defects in these mutants affect the assembly of newly synthesized polymerase subunits into active enzyme or the incorporation of RNA polymerase into maturing virions; once synthesized at the permissive temperature, the mutant polymerases are able to function in the initiation of subsequent rounds of infection at the nonpermissive temperature.
选择特定痘苗病毒基因中的温度敏感突变：编码抗膦酰乙酸、温度敏感 DNA 聚合酶的病毒突变体的分离和表征。
影响因子：
3.7
作者：
Sridhar,P;Condit,RC
通讯作者：
Condit,RC