title: Secondary structure of a channel-forming protein: porin from E. coli outer membranes.
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.
authors.forename: B
authors.initials: B
authors.lastname: Kleffel
authors.forename: R M
authors.initials: RM
authors.lastname: Garavito
authors.forename: W
authors.initials: W
authors.lastname: Baumeister
authors.forename: J P
authors.initials: JP
authors.lastname: Rosenbusch
mesh_terms: D001425:Bacterial Outer Membrane Proteins; D004926:Escherichia coli / Q000032:analysis*; D018272:Porins; D011487:Protein Conformation; D013055:Spectrophotometry, Infrared; D014961:X-Ray Diffraction
chemical_list: D001425:Bacterial Outer Membrane Proteins; D018272:Porins