Structure and Function Studies on Proteins from Predatory Bacteria

Bdellovibrio bacteriovorus is a small predatory bacterium able to invade and kill many different Gram-negative bacterial prey (including human, animal and crop pathogens; e.g. Pseudomonas, Salmonella, Burkholderia, Escherichia, Acinetobacter and spirochaetes). Our ultimate goal is to understand the “predatosome”, a group of unique proteins that Bdellovibrio uses for invasion and killing, and be able to use Bdellovibrio as a “living antibiotic”. Bdellovibrio collide with prey in a free-living attack phase, then attach to the outer surface and initiate a predatory phase involving membrane penetration and entry into the prey periplasm. Once inside, the point of entry is resealed and, as it enters, Bdellovibrio converts the rod-shaped prey into a stable rounded structure termed the bdelloplast. Prey material may then be digested without interference from competitors; the predator grows into a filament that divides into 4-9 progeny cells which are then released to begin the attack phase anew.

The Lovering laboratory focuses on protein:structure function studies, primarily using x-ray crystallography to determine high-resolution structures of interest. With our collaborators at Nottingham (Sockett group), we are pursuing several project areas at the moment, including (but not limited to), (i) how Bdellovibrio breaches its prey, (ii) regulation of the predatory lifestyle by the important second messanger cyclic-di-GMP, (iii) what the specific function of unique predation-upregulated proteins are (Bdellovibrio possesses a relatively large amount of genes with no strong homology to other organisms), and (iv) how Bdellovibrio manipulates the host cell wall during predation.

The student will learn a variety of techniques including cloning & molecular biology, protein production and purification, x-ray crystallography (from crystallization all the way through until structure modelling, refinement & interpretation), and other various protein biophysical techniques.