Structural comparison of the plant satellite viruses
Structural comparison of the plant satellite viruses
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DOI：
10.1006/viro.1995.0068
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发表时间：
1995-12-20
期刊：
影响因子：
3.7
通讯作者：
McPherson, A
中科院分区：
文献类型：
--
作者：
Ban, N;Larson, SB;McPherson, A
现在可以获得三种植物卫星病毒的详细结构：卫星烟草坏死病毒（STNV）、卫星烟草花叶病毒（STMV）和卫星黍花叶病毒（SPMV）。因此，可以比较病毒蛋白质亚基的三级结构、它们的四级相互作用以及蛋白质亚基与RNA基因组的相互作用。该分析表明，尽管蛋白质单体中具有共同的功能和“果冻卷”基序的保存，但这三种病毒却显着不同。差异包括二级结构元件的排列、相邻亚基的相互作用以及亚基相对于二十面体对称轴的配置。然而，在这三种病毒中，果冻卷的窄端形成了五重接触。五重蛋白质相互作用是围绕 STNV 的 Ca2+ 离子、STMV 的阴离子以及 SPMV 的阴离子进行组织的。使用 H2O/D2O 溶剂对比变化的低分辨率中子衍射研究揭示了 STNV 内 RNA 基因组的大致位置。对于 SPMV，衣壳内部的电子密度区域可以分配给 RNA，尽管不可能对核酸进行建模。只有 STMV 的核酸在选择密度图中可见，这表现为与每个外壳蛋白二聚体相关的双螺旋 RNA 片段。这里提出的观察结果没有为任何常见的进化关系提供支持。 (C) 1995 学术出版社
Detailed structures are now available for three plant satellite viruses, satellite tobacco necrosis virus (STNV), satellite tobacco mosaic virus (STMV), and satellite panicum mosaic virus (SPMV). It is, therefore, possible to compare the tertiary structure of viral protein subunits, their quaternary interactions, and the interactions of protein subunits with the RNA genome. This analysis indicates that, in spite of common function and preservation of a ''jelly-roll'' motif in the protein monomer, the three viruses are remarkably different The differences include the arrangement of secondary structural elements, interactions of adjacent subunits, and the disposition of subunits relative to icosahedral symmetry axes. In each of the three viruses, however, the narrow end of the jelly roll forms fivefold contacts. The fivefold protein interactions are organized about a Ca2+ ion for STNV, an anion for STMV, and, apparently, neither of these for SPMV. Low-resolution neutron diffraction studies using H2O/D2O solvent contrast variation revealed the general location of the RNA genome within the STNV. In the case of SPMV, regions of electron density on the interior of the capsid could be assigned to RNA, although it was not possible to model the nucleic acid. Only for STMV was nucleic acid visible in election density maps, and this was manifested as double-helical RNA segments associated with each coat protein dimer. The observations presented here provide no support for any common evolutionary relationship. (C) 1995 Academic Press, Inc.