Structural investigations of outer membrane proteins from Escherichia coli.

The receptor of phage lambda of Escherichia coli W3110, and matrix porin from E. coli BE have been crystallized. Porin occurs in two crystal forms whose packing arrangements are different, allowing the conclusion that crystal growth occurs from monodisperse protein-detergent complexes. The tetragonal form yields resolution to 2.9 A. The hexagonal form allows conclusive support for the hypothesis that a large fraction of the polypeptide is present in beta-pleated sheet structure with the strands nearly parallel to the normal of the membrane plane.