Pina Jason E, Lee Kuo Hao, Ytreberg F Marty
School of Physics, Astronomy, and Computational Sciences, George Mason University, Fairfax, VA 22030 USA.
J Biol Phys. 2012 Jun;38(3):397-404. doi: 10.1007/s10867-011-9260-6. Epub 2012 Jan 21.
It is known that the presence of calcium ions (Ca(2 + )) is necessary for the enterobacterial virus ΦX174 to inject its DNA into the host cell, and that some mutations in the major capsid proteins lead to better survivability at higher temperatures. Our goal in the current study is to determine the physical changes in both the wild-type and mutant virus due to the binding of Ca(2 + ). Thus, we performed molecular dynamics simulations of the ΦX174 major capsid protein complex with and without Ca(2 + ) bound. Our results show that binding of Ca(2 + ) leads to energetic and dynamical changes in the virus proteins. In particular, the results suggest that binding of Ca(2 + ) is energetically favorable and that the mutation leads to increased fluctuations of the protein complex (especially with the calcium ions bound to the complex), which may increase the rate of genome packaging and ejection for ΦX174.
已知钙离子（Ca(2 +)）的存在对于肠道细菌病毒ΦX174将其DNA注入宿主细胞是必要的，并且主要衣壳蛋白中的一些突变导致在较高温度下具有更好的生存能力。我们当前研究的目标是确定野生型和突变型病毒由于Ca(2 +)的结合而发生的物理变化。因此，我们对结合和未结合Ca(2 +)的ΦX174主要衣壳蛋白复合物进行了分子动力学模拟。我们的结果表明，Ca(2 +)的结合导致病毒蛋白的能量和动力学变化。特别是，结果表明Ca(2 +)的结合在能量上是有利的，并且突变导致蛋白质复合物的波动增加（特别是当钙离子与复合物结合时），这可能会增加ΦX174的基因组包装和释放速率。
