title: Visualization of beta-sheets and side-chain clusters in two-dimensional periodic arrays of streptavidin on phospholipid monolayers by electron crystallography.
abstract: The biotin-binding protein streptavidin was crystallized as two-dimensional periodic arrays on biotinylated phospholipid monolayers. Electron diffraction patterns and images of the arrays embedded in vitreous ice were recorded to near-atomic resolution. Amplitudes and phases of structure factors were computed and combined to produce a 3 A projection density map. The reliability of the map was verified by comparing it to the available x-ray atomic model of the molecule. Projection densities from beta-strands and some amino acid side chains were identified from the electron cryomicroscopy map. These results demonstrate the first near-atomic image of this type of protein periodic array by electron crystallography, which has a great potential to aid in the structural characterization of molecular arrays engineered on a monolayer for various basic or biotechnological applications.
authors.affiliation: Department of Molecular Physiology and Biophysics, W. M. Keck Center for Computational Biology, Baylor College of Medicine, Houston, Texas 77030, USA.
authors.forename: A J
authors.initials: AJ
authors.lastname: Avila-Sakar
authors.forename: W
authors.initials: W
authors.lastname: Chiu
mesh_terms: D000595:Amino Acid Sequence; D001426:Bacterial Proteins / Q000737:chemistry*; D055592:Biophysical Phenomena; D001703:Biophysics; D003461:Crystallography / Q000379:methods*; D018360:Crystallography, X-Ray; D004583:Electrons; D008958:Models, Molecular; D008969:Molecular Sequence Data; D015394:Molecular Structure; D010743:Phospholipids; D011487:Protein Conformation; D017433:Protein Structure, Secondary; D019809:Streptavidin
chemical_list: D001426:Bacterial Proteins; D010743:Phospholipids; D019809:Streptavidin