Affiliation: | From the ‡Gene Center and Department of Biochemistry, Center for Integrated Protein Science Munich (CIPSM), Ludwig-Maximilians-Universität München, Feodor-Lynen-Strasse 25, 81377 Munich and ;the §Institut für Mikrobiologie, Universität Regensburg, Universitätsstrasse 31, D-93053 Regensburg, Germany |