A new twist on drug design: AdhE spirosomes as cross species anti-virulence targets
In their quest to develop new compounds to block a range of infections we have been studying a bacterial protein called AdhE. AdhE is important because when it is deleted from pathogenic E. coli (str. O157:H7) it causes an attenuation of virulence and a reduction in expression of the major system used to attach to host cells. AdhE oligomerises in vivo and in vitro to form long (15-120 nm) filaments, called spirosomes, that can be visualised using electron microscopy. These are assumed to be an important aspect of the enzymatic efficiency of the protein. Importantly we have solved the high-resolution structure of the protein and identified lead compounds that bind and inhibit spirosome formation. However, there are several outstanding questions that we propose to address, thereby enhancing our understanding of how AdhE spirosomes work. This basic knowledge will help us to translate our work in the longer-term and to develop specific inhibitors that might function against a range of Gram-negative pathogens. Specifically, we seek answers to the following questions:
1 Why are AdhE spirosomes formed and how is this regulated?
2 Do AdhE spirosomes channel substrates?
3.Where is the binding site for the lead compounds?
4 Does AdhE influence expression of T3SSs in other species?
To address these questions we will use SAXS, AUC (University of Glasgow) and molecular dynamics simulations (in collaboration with Prof Syma Khalid (University of Southampton)). We will also aim to determine where compounds bind on spirosomes by performing cryo-EM studies in collaboration with Prof Ji-Joon Song (KAIST, Korea). To widen our understanding of the relevance for other pathogens, we will generate adhE deletions in other Gram-negative species and perform virulence-based assays with each pathogen.
The work requires a motivated protein biochemist/structural biologist who is keen to take on an exciting project. Informal enquiries to Olwyn or Andrew:
