Dieter Oesterhelt

Learn More
The square halophilic archaeon Haloquadratum walsbyi dominates NaCl-saturated and MgCl2 enriched aquatic ecosystems, which imposes a serious desiccation stress, caused by the extremely low water activity. The genome sequence was analyzed and physiological and physical experiments were carried out in order to reveal how H. walsbyi has specialized into its(More)
Heterogenous nucleation on small molecule crystals causes a monoclinic crystal form of bacteriorhodopsin (BR) in which trimers of this membrane protein pack differently than in native purple membranes. Analysis of single crystals by nano-electrospray ionization-mass spectrometry demonstrated a preservation of the purple membrane lipid composition in these(More)
Lag1p and Lac1p are two homologous transmembrane proteins of the endoplasmic reticulum in Saccharomyces cerevisiae. Homologous genes have been found in a wide variety of eukaryotes. In yeast, both genes, LAC1 and LAG1, are required for efficient endoplasmic reticulum-to-Golgi transport of glycosylphosphatidylinositol-anchored proteins. In this study, we(More)
We report the sequence of the Halobacterium salinarum strain R1 chromosome and its four megaplasmids. Our set of protein-coding genes is supported by extensive proteomic and sequence homology data. The structures of the plasmids, which show three large-scale duplications (adding up to 100 kb), were unequivocally confirmed by cosmid analysis. The chromosome(More)
Atomic force microscopy and single-molecule force spectroscopy were combined to image and manipulate purple membrane patches from Halobacterium salinarum. Individual bacteriorhodopsin molecules were first localized and then extracted from the membrane; the remaining vacancies were imaged again. Anchoring forces between 100 and 200 piconewtons for the(More)
Halobacterium halobium has right-handed helical flagella. During the logarithmic phase of growth, cells are predominantly monopolar, whereas in the stationary phase they are mostly bipolarly flagellated. The flagellar bundle consists of several filaments. Halobacteria swim forward by clockwise and backwards by counterclockwise rotation of their flagella.(More)
Natronomonas pharaonis is an extremely haloalkaliphilic archaeon that was isolated from salt-saturated lakes of pH 11. We sequenced its 2.6-Mb GC-rich chromosome and two plasmids (131 and 23 kb). Genome analysis suggests that it is adapted to cope with severe ammonia and heavy metal deficiencies that arise at high pH values. A high degree of nutritional(More)
Halorhodopsin, an archaeal rhodopsin ubiquitous in Haloarchaea, uses light energy to pump chloride through biological membranes. Halorhodopsin crystals were grown in a cubic lipidic phase, which allowed the x-ray structure determination of this anion pump at 1.8 angstrom resolution. Halorhodopsin assembles to trimers around a central patch consisting of(More)