Harald Engelhardt

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Most bacteria contain a peptidoglycan (PG) cell wall, which is critical for maintenance of shape and important for cell division. In contrast, Planctomycetes have been proposed to produce a proteinaceous cell wall devoid of PG. The apparent absence of PG has been used as an argument for the putative planctomycetal ancestry of all bacterial lineages. Here we(More)
Tom40 is the main component of the preprotein translocase of the outer membrane of mitochondria (TOM complex). We have isolated Tom40 of Neurospora crassa by removing the receptor Tom22 and the small Tom components Tom6 and Tom7 from the purified TOM core complex. Tom40 is organized in a high molecular mass complex of approximately 350 kD. It forms a high(More)
The major outer membrane protein (Omp34) of Acidovorax delafieldii (formerly Pseudomonas delafieldii) was purified to homogeneity and was characterized biochemically and functionally. The polypeptide has an apparent molecular weight (Mr) of 34,000, and it forms stable oligomers at pH 9.0 in the presence of 10% octylpolyoxyethylene or 2% lithium dodecyl(More)
The functional properties of the major outer-membrane protein of Acidovorax delafieldii, the anion-selective porin Omp34, were investigated in artificial membranes. Detergent-solubilized porin incorporates into the membrane in a undirectional orientation solely determined by protein features. This enabled us to characterize the vectorial properties of the(More)
Blue-pigmented exudates arise as droplets on sporulated lawns of Streptomyces coelicolor M110 grown on agar plates. Our electron microscopical and biochemical studies suggest that droplets contain densely packed vesicles with large assemblies of different protein types and/or the polyketide antibiotic actinorhodin. Frozen-hydrated vesicles were unilamellar(More)
The open channel characteristics of the bacterial porin Omp32 from Comamonas acidovorans were investigated by means of conductance measurements in planar lipid bilayers of the Montal-Mueller type. Particularly at low salt conditions (< or = 30 mM KCl) Omp32 exhibited some unusual asymmetric and nonlinear functional properties. Current-voltage relationship(More)
The anion-selective porin Omp34 from Acidovorax delafieldii was unidirectionally reconstituted in planar lipid membranes. Pore closing was recorded particularly at low salt conditions for negative and positive membrane potentials in the range of +/-10 to +/-100 mV. Relaxation curves were fitted by exponential functions in order to describe and to analyze(More)
Bactofilins are novel cytoskeleton proteins that are widespread in Gram-negative bacteria. Myxococcus xanthus, an important predatory soil bacterium, possesses four bactofilins of which one, BacM (Mxan_7475) plays an important role in cell shape maintenance. Electron and fluorescence light microscopy, as well as studies using over-expressed, purified BacM,(More)
BACKGROUND AND STUDY AIMS The goal of this study was to analyze the bowel cleansing methods currently used for pediatric colonoscopy in terms of effectiveness, tolerance and safety. PATIENTS AND METHODS Data from 768 colonoscopies reported by 28 centers were registered in an online database for further analysis. Binary logistic regression was used to(More)
Most halophilic Archaea of the class Halobacteriaceae depend on the presence of several molar sodium chloride for growth and cell integrity. This poses problems for structural studies, particularly for electron microscopy, where the high salt concentration results in diminished contrast. Since cryo-electron microscopy of intact cells provides new insights(More)