Dr. Eric R. Geertsma
Junior Professor
Biocenter N200/1.08
Phone +49-(0)69-798-29255
ax: +49-(0)69-798 29244


Beate Braungart
Administrative assistant
Biocenter N200/1.10
Phone +49-(0)69-798-29238
Fax: +49-(0)69-798 29244


Membrane Biochemistry -
Structure and Function of Secondary Transport Proteins

In all pro- and eukaryotic cells, compartments are defined by biological membranes. The crucial exchange of information and physical compounds between different compartments is performed by a large variety of proteins residing in these membranes. Despite the important role of these membrane proteins, our mechanistic understanding of how they accomplish this task is still very limited. This is primarily caused by the paucity of high-resolution structural information on membrane proteins.
Our lab studies the transport mechanism of secondary transporters, one of the most occurring transporter types in all kingdoms of life. Secondary transporters use the electrochemical energy stored in ion- or solute gradients across membranes to drive transport. Transport results from a series of conformational changes during which a central substrate binding site is alternately exposed to both sides of the membrane. We aim to obtain several high resolution structures of specific secondary transporters in different conformations and complement this with detailed functional characterization and studies of their conformational dynamics.

Studying membrane proteins requires the availability of significant amounts of pure, functional, stable and homogenous protein. This is not trivial for membrane proteins due to their low natural abundance, recalcitrant behavior towards overexpression and poor stability in the detergent-solubilized state. To overcome specific challenges that we encounter, we develop novel enabling technologies for membrane protein research (see Methodology). In addition we study membrane protein biogenesis.