Mon, Apr 24 4:00pm to 7:00pm
2033 Young Hall
Speaker Prof. Michael F. Hagan
Hosted by
Dept. of Chemistry and Biochemistry, UCLA

"Dynamical Assembly Pathways of Viruses and Bacterial Microcompartments"

Abstract: The self-assembly of a protein shell around a cargo is a common mechanism of encapsulation in biology. For example, in many virus families an icosahedral protein shell (capsid) assembles around the viral nucleic acid to form an infectious virion. In this talk I will describe coarse-grained computational models developed to describe this processes, with a focus on understanding how the material properties of the cargo can direct its encapsulation and determine the morphology of the assembled shell. I will consider three assembly processes (time permitting), each of which involves a cargo or substrate with different topology:  (1) I will first ask the question, “How large of a polymer can a self-assembling shell stuff inside of itself”, in the context of studying whether viruses are optimized for packaging their nucleic acids. (2) Many viruses envelope themselves in a lipid bilayer, by assembling on and budding through a host cell membrane. I will discuss how the properties of the cell membrane can affect the size of the assembling capsid. (3) Bacterial microcompartments (BMCs) are large, roughly icosahedral shells that act as organelles inside of bacteria. The best-known type of BMC is the carboxysome, which facilitates carbon fixation in cyanobacteria. Formation of a BMC proceeds by the self-assembly of a protein shell around a dense fluid complex of enzymes and other components. I will discuss how the properties of the fluid cargo affect the assembly pathways and size of the BMC.


Location: 2033 Young Hall

Time: 4:00 PM


Location: 3037 Young Hall

Time: 5:15 PM