文章基本信息

标题：How the phage T4 injection machinery works including energetics, forces, and dynamic pathway
本地全文：下载
作者：Ameneh Maghsoodi ; Anupam Chatterjee ; Ioan Andricioaei 等
期刊名称：Proceedings of the National Academy of Sciences
印刷版ISSN：0027-8424
电子版ISSN：1091-6490
出版年度：2019
卷号：116
期号：50
页码：25097-25105
DOI：10.1073/pnas.1909298116
出版社：The National Academy of Sciences of the United States of America
摘要：The virus bacteriophage T4, from the family Myoviridae , employs an intriguing contractile injection machine to inject its genome into the bacterium Escherichia coli . Although the atomic structure of phage T4 is largely understood, the dynamics of its injection machinery remains unknown. This study contributes a system-level model describing the nonlinear dynamics of the phage T4 injection machinery interacting with a host cell. The model employs a continuum representation of the contractile sheath using elastic constants inferred from atomistic molecular-dynamics (MD) simulations. Importantly, the sheath model is coupled to component models representing the remaining structures of the virus and the host cell. The resulting system-level model captures virus–cell interactions as well as competing energetic mechanisms that release and dissipate energy during the injection process. Simulations reveal the dynamical pathway of the injection process as a “contraction wave” that propagates along the sheath, the energy that powers the injection machinery, the forces responsible for piercing the host cell membrane, and the energy dissipation that controls the timescale of the injection process. These results from the model compare favorably with the available (but limited) experimental measurements..
关键词：bacteriophage T4 ; injection machinery ; sheath contraction ; dynamical pathway