Electrophysiological study & biotechnological implementation of the curli secretion-assembly machinery. (FWOSB104)

In Gram-negative bacteria, Curli fibres are the major constituent of the extracellular matrix needed to form bacterial communities within a biofilm. Curli are fibres belonging to a class of functional amyloids and are produced by dedicated biosynthetic pathway. The pathway constitutes several curli specific genes, (csg), encoding curli subunits. This project will study interaction dynamics of CsgA, the major curli structural subunit, with the translocation and assembly complex formed by: the membrane channel CsgG, the periplasmic accessory CsgE, and the fibre assembly factor CsgF. Interaction dynamics will be characterized by electrophysiology in lipid bilayers. Preliminary structural data indicated dynamic states of CsgF. This will be corroborated by electrophysiology and the effect on CsgA. Additionally, the dynamics between CsgE, CsgA and CsgG will be studied .

Recent reports showed binding of CsgA to the outside of CsgG, this conflicts with the conventional model of CsgA translocation that postulated a role for CsgE in CsgA recruitment to CsgG. Furthermore, this project will integrate knowledge of curli to generate a novel Nanopore sensing based, protein detection system. Selective detection of target proteins is introduced by combining the curli subunits with Nanobodies. In brief, the project will take an electrophysiological approach to study curli sub unit interactions and develop novel Nanopore sensing applications utilizing the Curli system.

Keywords:Bacterial biofilms, Curli secretion and assembly, Bacterial outer membrane transport, Nanopore sensing

Disciplines:Proteins, Bacteriology, Membrane structure and transport, Medical biotechnology diagnostics