Exploring Bacterial Organelle Interactomes: A Model of the Protein-Protein Interaction Network in the Pdu Microcompartment
Figure 1
An idealized model of the Pdu MCP shell and its encapsulated pathway.
The MCP shell is assembled from a few thousand copies of proteins belonging to the BMC (bacterial microcompartment) protein family. Several distinct paralogs from the BMC family are present within a single shell. BMC proteins self-assemble into cyclical hexamers (in blue). Also present in fewer copies are proteins from a distinct family, referred to as BMVs, which are pentameric proteins (in yellow) forming the vertices of the polyhedral structure. The polyhedron is shown here idealized as an icosahedron, while the Pdu MCP is typically less regular in shape. Sequentially acting enzymes (in black) carrying out the Pdu pathway are enclosed by the shell (A). The Pdu pathway degrades 1,2-propanediol to propionaldehyde via a B12-dependent catalytic mechanism, the aldehyde being subsequently converted to 1-propanol or propionyl-phosphate (B).