Protein-protein interactions and conformational changes of an ATP-binding-cassette (ABC) transporter: the maltose transport system of Salmonella typhimurium I


The family of ABC transport systems comprises a diverse class of transport proteins that couple the translocation of solutes across biological membranes to the free energy of ATP hydrolysis. Members of the family exist in organisms belonging to each of the three major kingdoms of life, some of them with medical relevance. Typically, an ABC transporter consists of two membrane-spanning domains that constitute a translocation pore and of two ATP-hydrolyzing (ABC) domains. Although tertiary structural informations are available for two complete transporters and several ABC domains, the molecular mechanism by which these proteins exert their functions is still poorly understood. However, conformational changes of domains upon binding of substrate and/or ATP are crucial to the transport process. Using the well-defined binding protein-dependent maltose ABC transporter of Salmonella typhimurium (MalEFGK2) as a model system, we propose to define sites of protein-protein interactions by employing synthetic peptide libraries and site-specific crosslinking. Furthermore, we will elucidate structural changes of the ABC subunit MalK relative to the transmembrane proteins MalFG during the transport cycle by fluorescence and electron paramagnetic spin resonance spectroscopy.


Principal investigators
Schneider, Erwin Prof. Dr. rer. nat. (Details) (Physiology of Microorganisms)

Financer
DFG: Sachbeihilfe

Duration of project
Start date: 01/2004
End date: 03/2006

Publications

Daus, M.L., Landmesser, H., Schlosser, Müller, P., Herrmann, A., Schneider, E. (2006): ATP induces conformational changes of periplasmic loop regions of the maltose ATP-binding cassette transporter. J. Biol. Chem. 281, 3856-3865



Blüschke, B., Volkmer-Engert, R., Schneider, E. (2006): Topography of the surface of the signal transducing protein EIIAGlc that interacts with the MalK subunits of the maltose ATP-binding cassette transporter (MalFGK2) of Salmonella typhimurium. J. Biol. Chem. 281, in press


Last updated on 2022-07-09 at 23:06