Projekte

Understanding the mechanistic details of active membrane transport on a structural basis is a long-term goal of our group. The aim here is to continue our ongoing work towards structure determination of an ABC transporter and to extend our cope to further active primary and secondary transporters and the F1F0-ATPase.

Together with W. Boos (TP A1) we have solved two partial structures of the bacterial maltose ABC importer, i.e. the structures of the traffic ATPase component (MaIK) and of the periplasmic binding protein (MaIE, alias TMBP) from the thermophilic archaebacterium Termococcus litoralis. Moreover, we have obtained crystals of the entire transporter consisting of the transmembrane component (MaIFG) and the attached traffic ATPase (adimer of MaIK). Here we intend to complete the structure determination of the maltose transporter in as many conformations as possible.Experience obtained in this collaboration provides us with good technical grounds to attempt the overexpression, crystallization and structure determination of other transporters, as listed below:Together with TP A4, we aim at crystallizing the eukaryotic ABC bile salt exporter, Bsep. Together with TP A7, we will try to solve the structure of the entire F1F0-ATPase complex driven by a transmembrane sodium gradient. Secondary active transporters, i.e., permeases which use the free energy of an electrochemical gradient for transport, will jointly be analyzed. We will first focus on aspects of their assembly and organisation, and later attempt crystallisation of the transporter itself: The renal Na/Pi symporter (with TP A2) and its cytoplasmic PDZ-binding domain.The extracellular glycosidase-like domain of an amino acid transporter (with TP A5). This broad collaborative approach will result in the determination of new structures which will provide new insights into activetransport mechanisms.

• Diederichs, Kay - Projektleiter*in

• FB Biologie