Bacteriophage P22 capsid size determination: Roles for the coat protein telokin-like domain and the scaffolding protein amino-terminus
Bacteriophage P22 capsid size determination: Roles for the coat protein telokin-like domain and the scaffolding protein amino-terminus
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DOI：
10.1016/j.virol.2011.06.025
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发表时间：
2011-09-01
期刊：
影响因子：
3.7
通讯作者：
Teschke, Carolyn M.
中科院分区：
文献类型：
--
作者：
Suhanovsky, Margaret M.;Teschke, Carolyn M.
正确大小和对称的二十面体衣壳的组装尚不清楚。噬菌体P22外壳蛋白残基F170对噬菌体组装过程中的构象转换至关重要。在这个位点上的替换导致六美排列的外壳蛋白的管状组装。分离到了F170A和F170K外壳蛋白突变体ts表型的基因内抑制子。抑制子反复出现在被毛蛋白端粒样结构域285位，导致被毛蛋白组装成细小的原衣壳和衣壳。衣壳的组装与取代氨基酸的侧链体积密切相关。我们假设285号位置较大的侧链扭转了类似末端蛋白的结构域，改变了亚基和衣壳体间接触的灵活性。因此，衣壳蛋白中单个氨基酸的替换就足以改变衣壳的大小。此外，变异外壳蛋白的组装产物受内部支架蛋白大小的影响。(C) 2011爱思唯尔公司版权所有。
Assembly of icosahedral capsids of proper size and symmetry is not understood. Residue F170 in bacteriophage P22 coat protein is critical for conformational switching during assembly. Substitutions at this site cause assembly of tubes of hexamerically arranged coat protein. Intragenic suppressors of the ts phenotype of F170A and F170K coat protein mutants were isolated. Suppressors were repeatedly found in the coat protein telokin-like domain at position 285, which caused coat protein to assemble into petite procapsids and capsids. Petite capsid assembly strongly correlated to the side chain volume of the substituted amino acid. We hypothesize that larger side chains at position 285 torque the telokin-like domain, changing flexibility of the subunit and intercapsomer contacts. Thus, a single amino acid substitution in coat protein is sufficient to change capsid size. In addition, the products of assembly of the variant coat proteins were affected by the size of the internal scaffolding protein. (C) 2011 Elsevier Inc. All rights reserved.