Martin A. Fisher School of Physics, Brandeis University, Waltham, Massachusetts 02453, USA.
J Chem Phys. 2022 Jun 28;156(24):245104. doi: 10.1063/5.0089556.
This article describes dynamical simulations of the assembly of an icosahedral protein shell around a bicomponent fluid cargo. Our simulations are motivated by bacterial microcompartments, which are protein shells found in bacteria that assemble around a complex of enzymes and other components involved in certain metabolic processes. The simulations demonstrate that the relative interaction strengths among the different cargo species play a key role in determining the amount of each species that is encapsulated, their spatial organization, and the nature of the shell assembly pathways. However, the shell protein-shell protein and shell protein-cargo component interactions that help drive assembly and encapsulation also influence cargo composition within certain parameter regimes. These behaviors are governed by a combination of thermodynamic and kinetic effects. In addition to elucidating how natural microcompartments encapsulate multiple components involved within reaction cascades, these results have implications for efforts in synthetic biology to colocalize alternative sets of molecules within microcompartments to accelerate specific reactions. More broadly, the results suggest that coupling between self-assembly and multicomponent liquid-liquid phase separation may play a role in the organization of the cellular cytoplasm.
本文描述了围绕双组份流体货物组装二十面体蛋白壳的动力学模拟。我们的模拟受到细菌微室的启发，细菌微室是在细菌中发现的蛋白壳，它们围绕参与某些代谢过程的酶和其他组件复合物组装。模拟表明，不同货物物种之间的相对相互作用强度在确定每个物种的封装量、它们的空间组织以及壳组装途径的性质方面起着关键作用。然而，有助于驱动组装和封装的壳蛋白-壳蛋白和壳蛋白-货物组分相互作用也会在某些参数范围内影响货物组成。这些行为受热力学和动力学效应的综合影响。除了阐明天然微室如何封装反应级联中涉及的多个成分外，这些结果还对合成生物学中努力将替代分子集合共定位在微室中以加速特定反应具有意义。更广泛地说，结果表明自组装和多组分液-液相分离之间的耦合可能在细胞质的组织中发挥作用。
