Protein subunit structures in the herpes simplex virus A-capsid determined from 400 kV spot-scan electron cryomicroscopy.
Protein subunit structures in the herpes simplex virus A-capsid determined from 400 kV spot-scan electron cryomicroscopy.
复制标题
通过 400 kV 点扫描电子冷冻显微镜测定单纯疱疹病毒 A 衣壳中的蛋白质亚基结构。
DOI：
10.1006/jmbi.1994.1594
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发表时间：
1994
影响因子：
5.6
通讯作者：
Chiu,W
中科院分区：
文献类型：
--
作者：
Zhou,ZH;Prasad,BV;Jakana,J;Rixon,FJ;Chiu,W
用400kV点扫描电子显微镜和计算机图像重建技术测定了单纯疱疹病毒1型A衣壳的三维结构，其分辨率为∼26？衣壳的密度图揭示了五角体、六角体、悲伤三联体等蛋白质亚单位的几个新的结构细节。我们的结构分析为将四种主要衣壳蛋白分配给这些不同的亚基提供了进一步的证据。VP5是一种150 kDa的主要衣壳蛋白，它同时组成了五角子和大部分六邻体亚基，有三个结构域：上菱形结构域、中茎样结构域和下锚定结构域。在不同的准等价环境中，VP5亚基之间存在明显的结构差异。一个角状的质量密度存在于每个六邻体亚基的末端，但在五角体亚基中缺失，被归属于VP26，一个12 kDa的小蛋白质。这六种类型的三联体具有相似但不相同的特征，包括两条腿和一个有尾巴的上结构域，它们被解释为分别由两个VP23副本(36 KDa)和一个VP19c副本(57 KDa)组成。每个三联体都有两个臂与相邻的VP5亚基相互作用，并且相互作用的模式在准等价的三联体中有所不同。衣壳的25？厚的底板是由六角形、五角形和三联体的亚基的低结构域紧密结合而成的。衣壳的内部可通过跨被膜通道和每个三联体底部的孔进入。在衣壳形态发生过程中，这些开口可能在基因组DNA和支架蛋白的运输中发挥作用。
The three-dimensional structure of the A-capsid of herpes simplex virus type-1 has been determined to a resolution of ∼ 26 Å by using 400 kV spot-scan electron cryomicroscopy and computer image reconstruction techniques. The density map of the capsid has revealed several new structural details in the protein subunits of pentons, hexons, sad triplexes. Our structural analysis has provided further evidence for the assignment of the four major capsid proteins to these various subunit. VP5, a 150 kDa major capsid protein that makes up both the penton and the bulk of the hexon subunits, has three domains: an upper diamond-shaped domain, a middle stem-like domain, and a lower anchoring domain. Structural differences are noticeable between the VP5 subunits in various quasi-equivalent environments. A horn-shaped mass density present at the distal end of each hexon subunit but missing from the penton subunit has been assigned to VP26, a minor 12 kDa protein. The six types of triplexes have similar, but not identical, features that include two legs and an upper domain that has a tail, which are interpreted to be formed from two copies of VP23 (36 kDa) and one copy of VP19c (57 kDa), respectively. Each triplex has two arms that interact with the adjacent VP5 subunits, and the modes of interaction vary among the quasi-equivalent triplexes. The 25 Å-thick floor of the capsid is formed by the close association of the lower domains of subunits from the hexons, pentons, and triplexes. The interior of the capsid is accessible through the trans-capsomeric channels and the holes at the base of each triplex. These openings may play a role in the transport of genomic DNA and scaffolding proteins during capsid morphogenesis.