Noble S, Nibert M L
Department of Biochemistry, University of Wisconsin-Madison, 53706, USA.
J Virol. 1997 Mar;71(3):2182-91. doi: 10.1128/JVI.71.3.2182-2191.1997.
A previously identified nucleoside triphosphatase activity in mammalian reovirus cores was further characterized by comparing two reovirus strains whose cores differ in their efficiencies of ATP hydrolysis. In assays using a panel of reassortant viruses derived from these strains, the difference in ATPase activity at standard conditions was genetically associated with viral genome segment L3, encoding protein lambda1, a major constituent of the core shell that possesses sequence motifs characteristic of other ATPases. The ATPase activity of cores was affected by several other reaction components, including temperature, pH, nature and concentration of monovalent and divalent cations, and nature and concentration of anions. A strain difference in the response of core ATPase activity to monovalent acetate salts was also mapped to L3/lambda1 by using reassortant viruses. Experiments with different nucleoside triphosphates demonstrated that ATP is the preferred ribonucleotide substrate for cores of both strains. Other experiments suggested that the ATPase is latent in reovirus virions and infectious subviral particles but undergoes activation during production of cores in close association with the protease-mediated degradation of outer-capsid protein mu1 and its cleavage products, suggesting that mu1 may play a role in regulating the ATPase.
通过比较两种呼肠孤病毒株的核心，对之前鉴定出的哺乳动物呼肠孤病毒核心中的核苷三磷酸酶活性进行了进一步表征，这两种呼肠孤病毒株的核心在ATP水解效率上存在差异。在使用源自这些毒株的一组重配病毒进行的测定中，标准条件下ATP酶活性的差异在遗传上与病毒基因组片段L3相关，L3编码蛋白lambda1，它是核心壳的主要成分，具有其他ATP酶特有的序列基序。核心的ATP酶活性受到其他几个反应成分的影响，包括温度、pH值、单价和二价阳离子的性质和浓度以及阴离子的性质和浓度。通过使用重配病毒，核心ATP酶活性对单价乙酸盐反应的毒株差异也被定位到L3/lambda1。用不同核苷三磷酸进行的实验表明，ATP是两种毒株核心的首选核糖核苷酸底物。其他实验表明，ATP酶在呼肠孤病毒颗粒和感染性子病毒颗粒中是潜伏的，但在核心产生过程中与外衣壳蛋白mu1及其裂解产物的蛋白酶介导降解密切相关时会被激活，这表明mu1可能在调节ATP酶中发挥作用。
