Interpretation of electron micrographs of adenovirus hexon arrays using a crystallographic molecular model.
Two types of two-dimensional arrays of purified adenovirus type 2 hexon have been obtained and analyzed by Fourier filtration of their electron micrographs. One array contained continuously close-packed hexons, distributed on a hexagonal p3 lattice, with a unit cell dimension of 94 +/- 2 A. The other array contained close-packed hexons with a regular absence, so that rings of six hexons related by sixfold symmetry formed a p6 unit cell. The cell dimension of the hexagonal array was 153 +/- 3 A, with neighboring hexons separated by 88 +/- 2 A. Smaller p6 arrays were also formed by hexons freed from complete virions on the microscope grid by treatment with distilled water. A molecular model of hexon, known from the X-ray crystallographic structure, was used to interpret Fourier-filtered images of the arrays, and to determine the relative orientations of the hexon molecules. The hexon-hexon interaction in the p3 array is that found in the virion facet, whereas that in the p6 array is a planar form of the interaction between peripentonal hexons around the vertex.
van Oostrum
J
J
Department of Biochemistry and Molecular Biophysics, College of Physicians and Surgeons, Columbia University, New York, New York 10032.
Smith
P R
PR
Mohraz
M
M
Burnett
R M
RM
D000256:Adenoviridae / Q000648:ultrastructure*; D003460:Crystallization; D005583:Fourier Analysis; D006801:Humans; D066298:In Vitro Techniques; D008854:Microscopy, Electron; D008958:Models, Molecular; D008968:Molecular Conformation