Prof Ben Berks

Prof Ben Berks

Nanomachines in the bacterial cell envelope

We study the molecular machines involved in forming the cell envelope of Gram-negative bacteria, with a special emphasis on those machines that move proteins and DNA across and around the cell envelope. These nanomachines have crucial roles in pathogenesis, motility, and antibiotic resistance, and are amongst the most mechanistically interesting proteins in the cell. 
The systems currently under study in our laboratory include:

The Type IX secretion system (T9SS) which is involved in severe dental disease as well as the maintenance of a healthy gut microbiota. This is the most complex protein transport system known and exports proteins through a huge pore in the outer membrane using the energy of the inner membrane proton electrochemical gradient.  

The Tat (twin-arginine translocation) protein transport system which exports folded proteins across the bacterial inner membrane. The Tat system is involved in a wide range of fundamental cellular processes in bacteria and is essential for the virulence of bacterial pathogens. The mechanism of Tat transport is radically different from that employed by other protein transporters, enabling it to translocate folded proteins without compromising the ion permeability barrier of the membrane.

Outer membrane protein biogenesis in the Bacteroidota. In this major bacterial phylum that dominates the human gut microbiome, formation of the outer membrane is very different from the well-studied Escherichia coli model.

Horizontal gene transfer between bacteria by conjugation. The main route for the spread of antibiotic resistance and other adaptive traits important for pathogens.

Gliding motility. The most rapid known type of cellular motility across solid surfaces. A complex internal network of machines powers adhesins along the outer surface of the cell.

Organisation of the Gram-negative bacterial cell envelope. We are particularly interested in the physical properties of the periplasm (the compartment between the two membranes of the Gram-negative cell envelope) and to what extent that composition and function of the outer membrane vary across the bacterial kingdom.  

Our work is grounded in protein biochemistry, bacterial cell biology, and bacterial genetics, to which we add a full range of cutting edge molecular techniques. In particular, we dissect the biological processes under study using live cell single molecule fluorescence imaging, and we collaborate with colleagues on the structural analysis of the nanomachines by cryoEM and other structural approaches.

Find out more from our group website, https://benberksgroup.web.ox.ac.uk