PDF(Pubmed)
Abstract：
The portal protein of tailed bacteriophage plays essential roles in various aspects of capsid assembly, motor assembly, genome packaging, connector formation, and infection processes. After DNA packaging is complete, additional proteins are assembled onto the portal to form the connector complex, which is crucial as it bridges the mature head and tail. In this study, we report high-resolution cryo-electron microscopy (cryo-EM) structures of the portal vertex from bacteriophage lambda in both its prohead and mature virion states. Comparison of these structures shows that during head maturation, in addition to capsid expansion, the portal protein undergoes conformational changes to establish interactions with the connector proteins. Additionally, the independently assembled tail undergoes morphological alterations at its proximal end, facilitating its connection to the head-tail joining protein and resulting in the formation of a stable portal-connector-tail complex. The B-DNA molecule spirally glides through the tube, interacting with the nozzle blade region of the middle-ring connector protein. These insights elucidate a mechanism for portal maturation and DNA translocation within the phage lambda system.
OBJECTIVE: The tailed bacteriophages possess a distinct portal vertex that consists of a ring of 12 portal proteins associated with a 5-fold capsid shell. This portal protein is crucial in multiple stages of virus assembly and infection. Our research focused on examining the structures of the portal vertex in both its preliminary prohead state and the fully mature virion state of bacteriophage lambda. By analyzing these structures, we were able to understand how the portal protein undergoes conformational changes during maturation, the mechanism by which it prevents DNA from escaping, and the process of DNA spirally gliding.
OBJECTIVE: The tailed bacteriophages possess a distinct portal vertex that consists of a ring of 12 portal proteins associated with a 5-fold capsid shell. This portal protein is crucial in multiple stages of virus assembly and infection. Our research focused on examining the structures of the portal vertex in both its preliminary prohead state and the fully mature virion state of bacteriophage lambda. By analyzing these structures, we were able to understand how the portal protein undergoes conformational changes during maturation, the mechanism by which it prevents DNA from escaping, and the process of DNA spirally gliding.
摘要：
尾噬菌体的门静脉蛋白在衣壳组装的各个方面发挥着重要作用，电机总成,基因组包装，连接器形成,和感染过程。DNA包装完成后,额外的蛋白质被组装到入口上形成连接体复合物，这是至关重要的，因为它桥接了成熟的头部和尾部。在这项研究中,我们报告了来自噬菌体λ的入口顶点的高分辨率低温电子显微镜（cryo-EM）结构在其前头和成熟病毒体状态下。这些结构的比较表明，在头部成熟期间，除了衣壳扩张，门静脉蛋白经历构象变化以建立与连接体蛋白的相互作用。此外,独立组装的尾巴在其近端经历形态改变，促进其与头尾连接蛋白的连接，并形成稳定的门户-连接器-尾巴复合物。B-DNA分子螺旋滑过试管,与中环连接蛋白的喷嘴叶片区域相互作用。这些见解阐明了噬菌体λ系统中门户成熟和DNA易位的机制。
目的：尾噬菌体具有独特的门户顶点，由与5倍衣壳壳相关的12个门户蛋白环组成。这种门静脉蛋白在病毒组装和感染的多个阶段中至关重要。我们的研究重点是检查入口顶点在其初步前端状态和噬菌体λ的完全成熟的病毒体状态下的结构。通过分析这些结构，我们能够理解门静脉蛋白在成熟过程中如何经历构象变化，它阻止DNA逃逸的机制，和DNA螺旋滑动的过程。
目的：尾噬菌体具有独特的门户顶点，由与5倍衣壳壳相关的12个门户蛋白环组成。这种门静脉蛋白在病毒组装和感染的多个阶段中至关重要。我们的研究重点是检查入口顶点在其初步前端状态和噬菌体λ的完全成熟的病毒体状态下的结构。通过分析这些结构，我们能够理解门静脉蛋白在成熟过程中如何经历构象变化，它阻止DNA逃逸的机制，和DNA螺旋滑动的过程。
