Topologically linked protein rings in the bacteriophage HK97 capsid
Topologically linked protein rings in the bacteriophage HK97 capsid
复制标题
DOI：
10.1126/science.289.5487.2129
复制
发表时间：
2000-09-22
期刊：
影响因子：
56.9
通讯作者：
Johnson, JE
中科院分区：
文献类型：
--
作者：
Wikoff, WR;Liljas, L;Johnson, JE
在3.6埃分辨率下测定了双链DNA噬菌体HK97成熟空壳的晶体结构。直径660埃的二十面体粒子包含420个亚基，并有一个新的折叠。衣壳成熟的最后一步是一个自催化反应，它在蛋白质之间产生420个异肽键。每个亚基通过侧链赖氨酸169与天冬酰胺356连接到两个相邻的亚基上。这产生了12个五聚体和60个六聚体的共价连接的亚基环，它们相互循环，产生蛋白质链状邮件：以二十面体对称排列的拓扑连接的蛋白质链环。以前在蛋白质中没有观察到链烷，它们为非常薄的HK97衣壳提供了一种稳定机制。
The crystal structure of the double-stranded DNA bacteriophage HK97 mature empty capsid was determined at 3.6 angstrom resolution. The 660 angstrom diameter icosahedral particle contains 420 subunits with a new fold. The final capsid maturation step is an autocatalytic reaction that creates 420 isopeptide bonds between proteins. Each subunit is joined to two of its neighbors by Ligation of the side-chain Lysine 169 to asparagine 356. This generates 12 pentameric and 60 hexameric rings of covalently joined subunits that loop through each other, creating protein chainmail: topologically linked protein catenanes arranged with icosahedral symmetry. Catenanes have not been previously observed in proteins and provide a stabilization mechanism for the very thin HK97 capsid.