Dr Sarah Coulthurst is a Reader and Wellcome Trust Senior Research Fellow at the University of Dundee, specialising in bacterial pathogens and protein secretion systems. In April, at the Microbiology Society Annual Conference 2018, she was awarded the Fleming Prize for the outstanding research conducted within 12 years of receiving her PhD.
Sarah uses Serratia marcescens as a model organism for studying inter- and intra-species competition. Her research focuses on Type VI secretion, a system for bacterial toxicity and communication through the injection of secreted effector molecules into target cells. Type VI secretion is analogous structurally to the bacteriophage tail, using a large contractile protein nanostructure to deliver toxins in a rapid-fire way. Immunity proteins are also produced by the host as a self-protective mechanism.
Sarah has identified a suite of novel effector proteins and has undertaken extensive analysis of their structure and function. In her Prize Lecture ‘How to kill your rivals: Type VI secretion system-mediated bacterial warfare’, she describes the elegant experiments that led to her group uncovering the anti-fungal properties of these effector proteins, and explains how they are recruited and regulated via the newly discovered immunity proteins. Her lecture finishes with a description of the role that the target cell plays in contributing to its own demise, forming a disulfide bond to form the active site and activate toxicity. The research presented by Sarah broadens significantly the role that Type VI secretion may play in polymicrobial communities.