Rossmann M G, Abad-Zapatero C, Murthy M R, Liljas L, Jones T A, Strandberg B
J Mol Biol. 1983 Apr 25;165(4):711-36. doi: 10.1016/s0022-2836(83)80276-9.
The structures of tomato bushy stunt virus, southern bean mosaic virus and satellite tobacco necrosis virus have been compared quantitatively. The organization of the shell domains of tomato bushy stunt virus and southern bean mosaic virus within the icosahedral envelope is identical. The wedge-shaped end of the subunit is closer to the fivefold or quasi-sixfold axes in all three viruses but the packing about the three- and twofold axes is quite different in satellite tobacco necrosis virus as compared to tomato bushy stunt virus or southern bean mosaic virus. The polypeptide folds of these viruses have greatest similarity in the beta-sheet region of the eight-stranded anti-parallel beta-barrel. The largest differences occur in the connecting segments. There is no clear indication of homologous amino acid sequences between southern bean mosaic virus and satellite tobacco necrosis virus. However, there is some conservation of the following functional groups. (1) Threonines and serines at the hexagonal-pentagonal wedge-shaped end of the subunit. (2) Lysines and arginines at the protein-RNA interface. (3) Hydrophobic residues in the cavity within the anti-parallel beta-barrel. (4) An aspartic acid near a site which binds Ca in tomato bushy stunt virus. (5) Ionic interactions in the contacts between fivefold-related subunits. These virus coat protein structures are not as similar to each other as the alpha and beta chains of hemoglobin but have greater likeness to one another than the NAD-binding domains of dehydrogenases or lysozymes from hen egg-white and T4 phage. The surface domains of tomato bushy stunt virus and southern bean mosaic virus are more like each other than like satellite tobacco necrosis virus. A divergent evolutionary tree is proposed on the basis of these observations.
已对番茄丛矮病毒、南方菜豆花叶病毒和烟草坏死卫星病毒的结构进行了定量比较。番茄丛矮病毒和南方菜豆花叶病毒的外壳结构域在二十面体包膜内的组织方式相同。在所有三种病毒中，亚基的楔形末端更靠近五重轴或准六重轴，但与番茄丛矮病毒或南方菜豆花叶病毒相比，烟草坏死卫星病毒围绕三重轴和二重轴的堆积方式有很大不同。这些病毒的多肽折叠在八链反平行β桶的β片层区域最为相似。最大的差异出现在连接片段中。南方菜豆花叶病毒和烟草坏死卫星病毒之间没有明显的同源氨基酸序列迹象。然而，以下功能基团存在一些保守性。（1）亚基六边形 - 五边形楔形末端的苏氨酸和丝氨酸。（2）蛋白质 - RNA界面处的赖氨酸和精氨酸。（3）反平行β桶内空腔中的疏水残基。（4）番茄丛矮病毒中与结合钙位点附近的天冬氨酸。（5）五重相关亚基之间接触中的离子相互作用。这些病毒衣壳蛋白结构彼此之间不像血红蛋白的α链和β链那样相似，但彼此之间的相似性比脱氢酶的NAD结合结构域或来自鸡蛋白和T4噬菌体的溶菌酶更大。番茄丛矮病毒和南方菜豆花叶病毒的表面结构域彼此之间比与烟草坏死卫星病毒更相似。基于这些观察结果提出了一个分歧进化树。
