University Potsdam, Institute for Biochemistry and Biology, Karl-Liebknecht-Strasse 24-25, Haus 20, 14476 Potsdam, Germany. steuer@agnld.uni-potsdam.de|University Potsdam, Institute for Biochemistry and Biology, Karl-Liebknecht-Strasse 24-25, Haus 20, 14476 Potsdam, Germany. steuer@agnld.uni-potsdam.de|University Potsdam, Institute for Biochemistry and Biology, Karl-Liebknecht-Strasse 24-25, Haus 20, 14476 Potsdam, Germany. steuer@agnld.uni-potsdam.de