Synthesis of Empty Bacterial Microcompartments, Directed Organelle Protein Incorporation, and Evidence of Filament-Associated Organelle Movement

Abstract

Compartmentalization is an important process, since it allows the segregation of metabolic activities and, in the era of synthetic biology, represents an important tool by which defined microenvironments can be created for specific metabolic functions. Indeed, some bacteria make specialized proteinaceous metabolic compartments called bacterial microcompartments (BMCs) or metabolosomes. Here we demonstrate that the shell of the metabolosome (representing an empty BMC) can be produced within E. coli cells by the coordinated expression of genes encoding structural proteins. A plethora of diverse structures can be generated by changing the expression profile of these genes, including the formation of large axial filaments that interfere with septation. Fusing GFP to PduC, PduD, or PduV, none of which are shell proteins, allows regiospecific targeting of the reporter group to the empty BMC. Live cell imaging provides unexpected evidence of filament-associated BMC movement within the cell in the presence of PduV.