Molecular Bacteriology

Rega Institute - Department of Microbiology and Immunology

Chairman: Prof. Dr. Tassos Economou

 

 

We want to understand how proteins are correctly targeted to cell membranes and subsequently cross or integrate into them. More than a third of the proteome of all cells resides in membranes or is secreted across lipid bilayers. Membrane proteins catalyze solute transport, energy conversion, sensing and signal transduction and cell division. 30-50% of the top drug targets comprise membrane proteins such as G-protein coupled receptors and ion channels. Secretory proteins mediate cell-cell signaling, surface attachment, pathogenic toxicity and enzymatic scavenging. Because of their biophysically challenging nature, elucidating structures and understanding catalytic mechanisms of membranome/secretome proteins remain major challenges. 

We mainly focus on two bacterial protein export pathways: a. The Sec pathway (ubiquitous and essential throughout life). and b. The Type III secretion (T3S) pathway (essential weapon for several Gram negative pathogens). Understanding protein trafficking helps us understand debilitating diseases such as cystic fibrosis that result from defective protein targeting. Other applications that stem from our basic research include novel antibacterials and vaccines, production of recombinant biopharmaceuticals, biosensors and bionanotechnology and combating biofilms.
 

Selected Publications

Gouridis, G., Karamanou, S., Sardis, M.-F., Schärer, M.A., Capitani, G. and Economou, A. (2013)
Quaternary dynamics of the SecA motor drive translocase catalysis.
Molecular Cell 52, 655-666
press release

Papanastasiou, M., Orfanoudaki, G., Koukaki, M., Kountourakis, N., Sardis, M.F., Aivaliotis, M., Karamanou, S. and Economou, A. (2013) 
The Escherichia coli Peripheral Inner Membrane Proteome.
Molecular and Cellular Proteomics 12, 599-610

Chen, L., Balabanidou, V., Remeta, D.P. Minetti, C.A.S.A., Portaliou, A.G., Economou, A. and Kalodimos, C.G. (2011)
Structural instability tuning as a regulatory mechanism in protein-protein interactions.
Molecular Cell 44, 734-44.

Gouridis, G., Karamanou, S., Gelis, I., Kalodimos, C.G. and Economou, A (2009)
Signal peptides are allosteric activators of the protein translocase. 
Nature 462, 363-36.

Gelis, I., Bonvin, A.M.J.J., Keramisanou , D.,Koukaki, M., Gouridis, G., Karamanou, S., Economou , A. and Kalodimos , C.G. (2007)
Structural Basis for Signal-Sequence Recognition by the Translocase Motor SecA as Determined by NMR. 
Cell 131, 756-769.

Karamanou, S., Gouridis, G., Papanikou, E., Sianidis, G., Gelis, I., Keramisanou, D., Vrontou, E., Kalodimos , C.G. and Economou, A. (2007)
Preprotein-controlled catalysis in the helicase motor of SecA. 
EMBO Journal 26, 2904-2911.