Protein Structure & Function


Anastassios
Economou 		IMBB Group Leader (Professor, Univ. of Crete)
Email address aeconomo@imbb.forth.gr
Phone +30-2810-391166
Fax +30-2810-391950
Lab web page http://ecoserver.imbb.forth.gr

 

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 (membranome) or is secreted across lipid bilayers (secretome). 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 atomic resolution 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 will help 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, production of recombinant biopharmaceuticals, biosensors and bionanotechnology.

 

Selected Publications
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.

Keramisanou , D., Biris, N., Gelis, I., Sianidis, G., Karamanou, S., Economou , A. and Kalodimos , C.G. (2006) Disorder-order folding transitions underlie catalysis in the helicase motor of SecA. Nature Structural and Molecular Biology 13: 594-602.