Alan Davidson

I first discovered the beauty and elegance of phages during my Ph.D. studies, which were focused on the DNA packaging enzyme of E. coli phage lambda. During my post-doctoral work at MIT, I switched to the field of protein structure and folding. I continued this work in my own lab investigating the thermodynamics and kinetics of folding of the SH3 domain. I have also worked extensively on the functioning of SH3 domains in budding yeast. Luckily, as time went on in my own lab, I was able to move back into the phage field.

My laboratory focuses on bacteriophages (phages), the viruses that infect bacteria. We are interested in:

1. CRISPR-Cas systems. CRISPR-Cas systems are an adaptive immunity system in bacteria. They operate in a manner similar to RNAi in eukaryotes and are widespread in both bacteria and archaea. Recently CRISPR-Cas systems have been adapted for genome editing in a wide variety of species including humans. We discovered the first examples of phage-encoded genes that inhibit the CRISPR-Cas systems, including Cas9 systems used for genome editing. We are currently studying the prevalence of these anti-CRISPR systems, how they work, and their evolutionary impact.
2. Phage-related entities encoded in bacterial genomes. These entities, such as R- and F-pyocins in P. aeruginosa or Photorhabdus Virulence Cassettes in other species, can mediate killing of other bacterial species or eukaryotic cells. Little is known of how these entities function. We aim to develop these phage-related entities into novel alternatives to antibiotics, tools for manipulating the microbiome, and agents for targeted treatment of human diseases.
3. How phage particles assemble. For these studies we combine techniques of structural biology (X-ray crystallography, NMR, and electron microscopy) with molecular biology and in vivo studies.
4. How phage genomes found within bacterial genomes (prophages) alter the physiology of the host bacteria. We pursue this work primarily in the pathogenic bacteria, Pseudomonas aeruginosa. We seek to understand how prophages affect virulence and pathogenesis of this organism. This work is relevant to Cystic Fibrosis patients in whom P. aeruginosa is a major cause of illness.

A major goal of my research program is to provide a fruitful training ground for my students where they can gain experience in as many techniques as possible, and develop independent projects based on their own interests and strengths.

Google Scholar Link: https://scholar.google.ca/citations?hl=en&pli=1&user=QNGk7pkAAAAJ

Appointments, Cross Affiliations, Memberships

Canada Research Chair in Bacteriophage-Based Technologies

Courses Taught

BCH2112 From chaperones to CRISPR-Cas: the incredible genius of phages
BCH473Y Advanced Research Project in Biochemistry
MGY377 Introductory Bacteriology

Awards

2001 Premier’s Research Excellence Award Government of Ontario