ROLE AND MECHANISM OF THE MATURATION CLEAVAGE OF VPO IN POLIOVIRUS ASSEMBLY - STRUCTURE OF THE EMPTY CAPSID ASSEMBLY INTERMEDIATE AT 2.9-ANGSTROM RESOLUTION
ROLE AND MECHANISM OF THE MATURATION CLEAVAGE OF VPO IN POLIOVIRUS ASSEMBLY - STRUCTURE OF THE EMPTY CAPSID ASSEMBLY INTERMEDIATE AT 2.9-ANGSTROM RESOLUTION
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DOI：
10.1002/pro.5560031005
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发表时间：
1994-10-01
期刊：
影响因子：
8
通讯作者：
HOGLE, JM
中科院分区：
文献类型：
--
作者：
BASAVAPPA, R;SYED, R;HOGLE, JM
已在2.9埃分辨率下确定了P1/马奥尼脊髓灰质炎病毒空衣壳的晶体结构。空衣壳与成熟病毒粒子的不同之处在于它们缺少病毒RNA，并且尚未经历VP0的稳定成熟裂解以产生成熟衣壳蛋白VP4和VP2。外表面和蛋白质外壳的大部分与成熟病毒粒子非常相似。这两种结构之间的主要差异集中在由衣壳蛋白N末端延伸部分在壳内表面形成的网络中。在空衣壳中，VP1的整个N末端延伸部分以及对应于VP4和VP2的N末端延伸部分是无序的，并且成熟病毒粒子中存在的许多稳定相互作用缺失。在空衣壳中，VP0的可裂解键距离由VP0裂解产生的末端在成熟病毒粒子中的位置约20埃。可裂解键位于壳内表面一个三叶形凹陷的边缘，这非常类似于菜豆荚斑驳病毒中的一个RNA结合位点。该结构为衣壳化的起始、VP0的RNA依赖性自催化裂解以及裂解在建立有序的N末端网络和产生稳定病毒粒子中的作用提出了合理的（并且最终可检验的）模型。
The crystal structure of the P1/Mahoney poliovirus empty capsid has been determined at 2.9 Angstrom resolution. The empty capsids differ from mature virions in that they lack the viral RNA and have yet to undergo a stabilizing maturation cleavage of VP0 to yield the mature capsid proteins VP4 and VP2. The outer surface and the bulk of the protein shell are very similar to those of the mature virion. The major differences between the 2 structures are focused in a network formed by the N-terminal extensions of the capsid proteins on the inner surface of the shell. In the empty capsids, the entire N-terminal extension of VP1, as well as portions corresponding to VP4 and the N-terminal extension of VP2, are disordered, and many stabilizing interactions that are present in the mature virion are missing. In the empty capsid, the VP0 scissile bond is located some 20 Angstrom away from the positions in the mature virion of the termini generated by VP0 cleavage. The scissile bond is located on the rim of a trefoil-shaped depression in the inner surface of the shell that is highly reminiscent of an RNA binding site in bean pod mottle virus. The structure suggests plausible (and ultimately testable) models for the initiation of encapsidation, for the RNA-dependent autocatalytic cleavage of VP0, and for the role of the cleavage in establishing the ordered N-terminaI network and in generating stable virions.