Partitivirus Structure Reveals a 120-Subunit, Helix-Rich Capsid with Distinctive Surface Arches Formed by Quasisymmetric Coat-Protein Dimers
- 作者：Wendy F. Ochoa ; Wendy M. Havens ; Robert S. Sinkovits ; Max L. Nibert ; Said A. Ghabrial ; Timothy S. Baker
- 关键词：MICROBIO ; PROTEINS
- 刊名：Structure
- 出版年：2008
- 期刊代码：143_09692126
- 类别：bio
- 出版时间：7 May 2008
- 卷：16
- 期：5
- 页码：776-786
- 文件大小：1720 K
摘要
Two distinct partitiviruses, Penicillium stoloniferum viruses S and F, can be isolated from the fungus Penicillium stoloniferum. The bisegmented dsRNA genomes of these viruses are separately packaged in icosahedral capsids containing 120 coat-protein subunits. We used transmission electron cryomicroscopy and three-dimensional image reconstruction to determine the structure of Penicillium stoloniferum virus S at 7.3 Å resolution. The capsid, 
350 Å in outer diameter, contains 12 pentons, each of which is topped by five arched protrusions. Each of these protrusions is, in turn, formed by a quasisymmetric dimer of coat protein, for a total of 60 such dimers per particle. The density map shows numerous tubular features, characteristic of 
helices and consistent with secondary structure predictions for the coat protein. This three-dimensional structure of a virus from the family Partitiviridae exhibits both similarities to and differences from the so-called “T = 2” capsids of other dsRNA viruses.
350 Å in outer diameter, contains 12 pentons, each of which is topped by five arched protrusions. Each of these protrusions is, in turn, formed by a quasisymmetric dimer of coat protein, for a total of 60 such dimers per particle. The density map shows numerous tubular features, characteristic of helices and consistent with secondary structure predictions for the coat protein. This three-dimensional structure of a virus from the family Partitiviridae exhibits both similarities to and differences from the so-called “T = 2” capsids of other dsRNA viruses.