Assembly and Maturation of a T = 4 Quasi-Equivalent Virus Is Guided by Electrostatic and Mechanical Forces

Viruses

Bradley M. Kearney¹ 

[1] Department of Integrative Structural and Computational Biology, The Scripps Research Institute, La Jolla, CA 92037, USA; E-Mail

关键词: virus maturation;    quasi-equivalence;    Nudaurelia capensis omega virus;    autoproteolysis;    tetravirus;    RNA insect virus;    non-enveloped viruses;   

DOI  :  10.3390/v6083348

来源: mdpi

【 摘 要 】

Nudaurelia capensis ω virus (NωV) is a eukaryotic RNA virus that is well suited for the study of virus maturation. The virus initially assembles at pH 7.6 into a marginally stable 480-Å procapsid formed by 240 copies of a single type of protein subunit. During maturation, which occurs during apoptosis at pH 5.0, electrostatic forces guide subunit trajectories into a robust 410-Å virion that is buttressed by subunit associated molecular switches. We discuss the competing factors in the virus capsid of requiring near-reversible interactions during initial assembly to avoid kinetic traps, while requiring robust stability to survive in the extra-cellular environment. In addition, viruses have a variety of mechanisms to deliver the genome, which must remain off while still inside the infected cell, yet turn on under the proper conditions of infection. We conclude that maturation is the process that provides a solution to these conflicting requirements through a program that is encoded in the procapsid and that leads to stability and infectivity.

【 授权许可】

CC BY   
© 2014 by the authors; licensee MDPI, Basel, Switzerland.