Bacterial microcompartments are protein shells found in bacteria that surround enzymes and other chemicals required for certain biological reactions. For example, the carboxysome is a type of microcompartment that enables bacteria to convert the products of photosynthesis into sugars (thus taking carbon out of the atmosphere). During the formation of a microcompartment, the outer protein shell assembles around hundreds of enzymes and chemicals required for the reaction. Because the intermediates in this assembly process are small and short-lived, it is hard to study in detail using experiments. It is therefore useful to develop computational models that can help explain how proteins collect the necessary cargo, and then assemble into an ordered shell with the cargo on the inside. The videos in this post show some examples of computer simulations of a model for bacterial microcompartment assembly, with each video corresponding to a different set of parameters that control the strengths of interactions among the proteins and cargo.
The study is described in the research article “Many-molecule encapsulation by an icosahedral shell” by Jason Perlmutter, Farzaneh Mohajerani, and Michael Hagan in eLife (eLife 2016;10.7554/eLife.14078).
|Video 1: Multistep assembly of a microcompartment encapsulating hundreds of molecules (I)|
|Video 2: Multistep assembly of a microcompartment encapsulating hundreds of molecules (II)|
|Video 3: Assembly of a microcompartment and encapsulation of hundreds of diffuse cargo molecules|