Méric C, Gouilloud E, Spahr P F
Department of Molecular Biology, University of Geneva, Switzerland.
J Virol. 1988 Sep;62(9):3328-33. doi: 10.1128/JVI.62.9.3328-3333.1988.
Rous sarcoma virus nucleocapsid protein p12 (NC) contains two conserved amino acid motifs, the Cys-His boxes, which constitute potential metal-binding domains. To try to understand the function of NC and of each of its Cys-His boxes during the viral life cycle, particularly in viral RNA packaging, we have used synthetic oligonucleotides to delete precisely either the proximal or the distal box, or both Cys-His boxes. The mutant DNAs were transfected into chicken embryo fibroblasts, and the virions produced in a transient assay were characterized biochemically for production of viral proteins and particles, RNA packaging, and infectivity. The results indicated the following. (i) The deletion of either the proximal or the distal box decreases the amount of viral RNA packaged in the particles and results in incomplete 70S dimer formation. (ii) The deletion of both boxes inhibits viral RNA packaging. (iii) The deletion of the proximal, but not the distal, box suppresses any detectable infectivity, while the deletion of the distal, but not the proximal, box lowers infectivity 100 to 200 times.
劳氏肉瘤病毒核衣壳蛋白p12（NC）含有两个保守的氨基酸基序，即半胱氨酸-组氨酸框，它们构成了潜在的金属结合结构域。为了试图了解NC及其每个半胱氨酸-组氨酸框在病毒生命周期中的功能，特别是在病毒RNA包装过程中的功能，我们使用合成寡核苷酸精确删除了近端或远端框，或两个半胱氨酸-组氨酸框。将突变DNA转染到鸡胚成纤维细胞中，并对瞬时测定中产生的病毒粒子进行生化表征，以检测病毒蛋白和颗粒的产生、RNA包装和感染性。结果如下：（i）删除近端或远端框会减少包装在颗粒中的病毒RNA量，并导致70S二聚体形成不完全。（ii）删除两个框会抑制病毒RNA包装。（iii）删除近端框而非远端框会抑制任何可检测到的感染性，而删除远端框而非近端框会使感染性降低100至200倍。
