Paredes A M, Heidner H, Thuman-Commike P, Prasad B V, Johnston R E, Chiu W
National Center for Macromolecular Imaging, Verna and Marrs McLean Department of Biochemistry, Baylor College of Medicine, Houston, Texas 77030, USA.
J Virol. 1998 Feb;72(2):1534-41. doi: 10.1128/JVI.72.2.1534-1541.1998.
We have determined the three-dimensional structures of the wild-type Sindbis virus and two of its mutants that retain the E3 sequence within PE2. Using difference imaging between these mutants and the wild-type virus, we have assigned a location for the 64-amino-acid sequence corresponding to E3 in the mutant spike complex. In the wild-type virus, the spike is composed of an E1-E2 heterotrimer. The E3 protein was found to protrude midway between the center of the spike complex and the tips. Based on these results and the work of others, we propose a distribution for the functional domains of the spike proteins within the structure of wild-type Sindbis virus. Within the structure of the virus, the E1 domains form the central portion of the spike complex, while the tips are formed by the E2 domains that flare out from the center of the complex. The structural similarity between these Sindbis virus mutants and Ross River virus suggests that E3 may also be present in the latter, which is also a member of the Alphavirus genus.
我们已经确定了野生型辛德毕斯病毒及其两个在PE2内保留E3序列的突变体的三维结构。通过对这些突变体和野生型病毒进行差异成像，我们在突变体刺突复合体中确定了与E3相对应的64个氨基酸序列的位置。在野生型病毒中，刺突由E1-E2异源三聚体组成。发现E3蛋白在刺突复合体中心和尖端之间的中间位置突出。基于这些结果以及其他人的研究工作，我们提出了野生型辛德毕斯病毒结构中刺突蛋白功能域的分布情况。在病毒结构中，E1结构域形成刺突复合体的中心部分，而尖端由从复合体中心向外展开的E2结构域形成。这些辛德毕斯病毒突变体与罗斯河病毒之间的结构相似性表明，后者（也是甲病毒属的成员）中可能也存在E3。
