Lander Gabriel C, Khayat Reza, Li Rui, Prevelige Peter E, Potter Clinton S, Carragher Bridget, Johnson John E
National Resource for Automated Molecular Microscopy, The Scripps Institute, La Jolla, CA 92037, USA.
Structure. 2009 Jun 10;17(6):789-99. doi: 10.1016/j.str.2009.04.006.
The portal channel is a key component in the life cycle of bacteriophages and herpesviruses. The bacteriophage P22 portal is a 1 megadalton dodecameric oligomer of gp1 that plays key roles in capsid assembly, DNA packaging, assembly of the infection machinery, and DNA ejection. The portal is the nucleation site for the assembly of 39 additional subunits generated from multiple copies of four gene products (gp4, gp10, gp9, and gp26), which together form the multifunctional tail machine. These components are organized with a combination of 12-fold (gp1, gp4), 6-fold (gp10, trimers of gp9), and 3-fold (gp26, gp9) symmetry. Here we present the 3-dimensional structures of the P22 assembly-naive portal formed from expressed subunits (gp1) and the intact tail machine purified from infectious virions. The assembly-naive portal structure exhibits a striking structural similarity to the structures of the portal proteins of SPP1 and phi29 derived from X-ray crystallography.
门户通道是噬菌体和疱疹病毒生命周期中的关键组成部分。噬菌体P22门户是由gp1组成的1兆道尔顿的十二聚体寡聚体,在衣壳组装、DNA包装、感染机制组装和DNA喷射中起关键作用。门户是由四个基因产物(gp4、gp10、gp9和gp26)的多个拷贝产生的另外39个亚基组装的成核位点,它们共同形成多功能尾部机器。这些组件以12倍(gp1、gp4)、6倍(gp10、gp9三聚体)和3倍(gp26、gp9)对称性组合排列。在这里,我们展示了由表达的亚基(gp1)形成的未组装的P22门户以及从感染性病毒粒子中纯化的完整尾部机器的三维结构。未组装的门户结构与通过X射线晶体学获得的SPP1和phi29门户蛋白的结构具有惊人的结构相似性。