The Gram-negative human pathogen Pseudomonas aeruginosa causes a wide range of infections with severe morbidity and mortality cases. Among many virulence factors produced by P. aeruginosa are several phospholipases generally known to contribute to nutrient utilization, phospholipid homeostasis, damage of host cell membranes and modulation of lipid signaling in eukaryotic cells. Here, we will study PlbF, a newly identified phospholipase B linked to biofilm formation and virulence of P. aeruginosa. The enzyme is anchored to the cytoplasmic membrane via a single transmembrane (TM) helix which is involved in the formation of homodimers. Recently, we solved the PlbF crystal structure which revealed a unique dimerisation mode through coiled-coil interactions of TM helices. In the crystal structure, fatty acid ligands bound in the active site were identified which may represent lipid messengers and could thus provide a link to virulence properties of P. aeruginosa. In this project, we aim to determine how the dynamics of mono- to dimerisation regulates the catalytic properties of PlbF. We furthermore want to elucidate the physiological role of PlbF for lipid signaling which becomes increasingly relevant for bacterial communication within and between cells, in particular during bacterial infections.
Project leaders: Prof. Dr. Karl-Erich Jaeger, , and Dr. Filip Kovacic,
Researchers: Julia Berger,