title: Three-dimensional structure of the surface layer protein of Aquaspirillum serpens VHA determined by electron crystallography.
abstract: The three-dimensional structure of the protein which forms the S layer of Aquaspirillum serpens strain VHA has been determined by electron microscopy. Structures have been reconstructed to a resolution of about 1.6 nm for single-layered specimens and about 4 nm for two-layered specimens. The structure, which has hexagonal symmetry, consists of a core in the shape of a cup, with six projections arising from the rim of the cup to join adjacent subunits at the threefold symmetry axes. The model is consistent with edge views of the S layer which have been obtained in this and other work. It is now clear from this work and from three-dimensional reconstructions of other bacterial S layers that a wide diversity exists in the morphology of surface layers.
mesh_terms: D001426:Bacterial Proteins / Q000032:analysis*; D003201:Computers; D003461:Crystallography; D006088:Gram-Negative Aerobic Bacteria / Q000032:analysis*; D007089:Image Enhancement; D008854:Microscopy, Electron; D008958:Models, Molecular; D011487:Protein Conformation; D013139:Spirillum
chemical_list: D001426:Bacterial Proteins