University of Dundee

Playing dirty during bacterial warfare

19 Jan 2018

Research from Dr Sarah Coulthurst’s group in the Division of Molecular Microbiology has provided new information on how bacteria fight with each other. Published today in Cell Reports, the work showed how the victimised cell’s own proteins can be hijacked by the actions of aggressive bacteria wielding a weapon called the ‘Type VI secretion system’.

Dr Coulthurst said, “The Type VI secretion system is a nano-machine used by many bacteria to deliver toxic effector proteins into rival bacterial cells. It plays an important role in allowing bacterial pathogens to compete with other bacteria in polymicrobial communities.”

“We discovered that incorporation of disulphide bonds by DsbA is required for proper assembly of an active Type VI secretion system in Serratia marcescens. In addition to this role in secretion system function in attacking cells, DsbA was also found to be essential for activation of certain incoming toxins in the targeted bacterial cells. Therefore, this work has revealed that Type VI secretion system-delivered effector proteins can hijack target cell functions.”

Photo from left: Laura Monlezun, Giuseppina Mariano (first author) and Sarah Coulthurst.