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Free keywords:
*Bacterial Outer Membrane Proteins; *Escherichia coli/an [Analysis]; Porins; Protein Conformation; Spectrophotometry, Infrared; Support, Non-U.S. Gov't; X-Ray Diffraction
Abstract:
Porin from Escherichia coli outer membranes has been analysed by high angle diffuse X-ray diffraction, and by attenuated total reflection infrared spectroscopy. These methods demonstrate independently that the majority of the polypeptide backbone is arranged in anti-parallel beta-pleated sheet structure. The average length of the beta-strands, which are oriented nearly normal to the membrane plane, is estimated to be 10-12 residues, independent of the method used. Although the details of strand arrangement (beta-barrels or stacked sheets) are not as yet known, porin represents the first transmembrane protein for which beta-structure has been established unequivocally.
