Structure of the outer membrane protein A transmembrane domain.
The outer membrane protein A of Escherichia coli (OmpA) is an intensely studied example in the field of membrane protein folding. We have determined the structure of the OmpA transmembrane domain consisting of residues 1-171, by X-ray diffraction analysis, to a resolution of 2.5 A. It consists of a regular, extended eight-stranded beta-barrel and appears to be constructed like an inverse micelle with large water-filled cavities, but does not form a pore. Surprisingly, the cavities seem to be highly conserved during evolution. The structure corroborates the concept that all outer membrane proteins consist of beta-barrels. The structure constitutes a beta-barrel membrane anchor that appears to be the outer membrane equivalent of the single-chain alpha-helix anchor of the inner membrane.
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Institut für Organische Chemie und Biochemie, Albert-Ludwigs-Universität, Freiburg im Breisgau, Germany.
Schulz
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D000595:Amino Acid Sequence; D001425:Bacterial Outer Membrane Proteins / Q000737:chemistry*; D018360:Crystallography, X-Ray; D004926:Escherichia coli / Q000737:chemistry*; D008051:Lipid Bilayers; D008958:Models, Molecular; D008969:Molecular Sequence Data; D017433:Protein Structure, Secondary; D017434:Protein Structure, Tertiary; D017386:Sequence Homology, Amino Acid
D001425:Bacterial Outer Membrane Proteins; D008051:Lipid Bilayers; C078167:OMPA outer membrane proteins