Orientation of porin channels in the outer membrane of Bordetella pertussis
Autor: | Benes L. Trus, Eva Kocsis, Alasdair C. Steven, M. Kessel, P. R. Smith, M J Brennan, J. H. Hannah |
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Rok vydání: | 1993 |
Předmět: |
Bordetella pertussis
Protein Conformation Cell Membrane Porins Trimer Crystal structure Biology Crystallography X-Ray biology.organism_classification Microbiology Folding (chemistry) Microscopy Electron Membrane protein Porin Image Processing Computer-Assisted Biophysics Molecule Bacterial outer membrane Molecular Biology Subcellular Fractions |
Zdroj: | Molecular Microbiology. 9:469-476 |
ISSN: | 1365-2958 0950-382X |
DOI: | 10.1111/j.1365-2958.1993.tb01708.x |
Popis: | Summary We have examined the surface topography and channel connectivity of a naturally crystalline porin that is known to be functional, and whose structure has not been perturbed by detergent extraction, A three-dimensional density map, calculated from two independent tilt series of negatively stained cell envelopes, reveals three separate channels per trimer on one side (the ‘smooth’ side), and a single common opening at the other (‘rough’) side. This arrangement is consistent with the molecular structures recently determined at high resolution by X-ray crystallography for three other porins after detergent solubilization, and implies that the Bordetella pertussis porin may have the same kind of folding. Surface relief maps calculated from electron micrographs of cell envelopes contrasted by unidirectional shadowing clearly show that the side with single opening (i.e. the rough side) represents the external surface. |
Databáze: | OpenAIRE |
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