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J F Deatherage

Publications and source records attributed to J F Deatherage.

9 recordsLinked to original sources
PubMed1990

Three-dimensional interactive graphics for displaying and modelling microscopic data.

EUCLID is a three-dimensional (3D) general purpose graphics display package for interactive manipulation of vector, surface and solid drawings on Evans and Sutherland PS300 series graphics processors. It is useful for displaying, comparing, measuring and modelling 3D microscopic images in real time. EUCLID can assemble groups of drawings into a composite drawing, while retaining the ability to operate upon the individual drawings within the composite drawing separately. EUCLID is capable of real time geometrical transformations (scaling, translation and rotation in two coordinate frames) and stereo and perspective viewing transformations. Because of its flexibility, EUCLID is especially useful for fitting models into 3D microscopic images.

Animals↗
PubMed1989

Three-dimensional reconstruction of the Z disk of sectioned bee flight muscle.

The three-dimensional structure of the central region of the Z disk of honeybee flight muscle has been determined to a resolution of 70 A by three-dimensional reconstruction from electron micrographs of tilted thin sections. The reconstructions show a complex assembly in which actin filaments terminate and are cross-linked together; a number of structural domains of this network are resolved in quantitative three-dimensional detail. The central region of the Z disk contains two sets of overlapping actin filaments of opposite polarity, which originate in the sarcomeres adjacent to the Z disk, and connections between these filaments. The filaments are deflected by the attachment of cross-links; spacing between filaments change by greater than 100 A during their passage through the Z disk. Each actin filament is linked by connecting structures to four filaments of opposite polarity and two filaments are of the same polarity. Four types of connecting density domain are observed in association with pairs of filaments of opposite polarity: C1, C2, C3, and C5. Two of these, C3 and C5, are associated with the ends of actin filaments. Another connection, C4, is associated with three filaments of the same polarity; C4 is threefold symmetric.

Animals↗
PubMed1989

Arrangement of filaments and cross-links in the bee flight muscle Z disk by image analysis of oblique sections.

Information from oblique thin sections and from three-dimensional reconstructions of tilted, transverse thin sections (Cheng, N., and J. F. Deatherage. 1989. J. Cell Biol. 108:1761-1774) has been combined to determine the three-dimensional structure of the honeybee flight muscle Z disk at 70-A resolution. The overall symmetry and structure of the Z disk and its relationship to the rest of the myofibril have been determined by tracing filaments and connecting elements on electron images of oblique sections which have been enhanced by a local crystallographic averaging technique. In the three-dimensional structure, the connecting density between actin filaments can be described as five compact, crystallographically nonequivalent domains. Features C1 and C2 are located on the transverse twofold rotation axes in the central plane of the Z disk. They are associated with the sides of actin filaments of opposite polarity. Features C3, C4, and C5 are present in two symmetry-related sets which are located on opposite sides of the central plane. C3 and C5 are each associated with two filaments of opposite polarity, interacting with the side of one filament and the end of the other filament. C3 and C5 may be involved in stabilizing actin filament ends inside the Z disk. The location of the threefold symmetric connection C4, relative to the thick filament of the adjacent sarcomere, is determined and its possible relationship to the C filament is considered.

Actin Cytoskeleton↗
PubMed1986

Alignment and merging of electron microscope images of frozen hydrated crystals of the T4 DNA helix destabilizing protein gp32*I.

Low dose cryoelectron microscopy has been used to record images and electron diffraction patterns of frozen hydrated crystals of the single-stranded DNA binding protein gp32*I. Fourier transforms from 13 image areas, corresponding to approximately 40,000 unit cells, were aligned by a minimal phase residual search and merged by vector addition in reciprocal space. Phases from the resulting composite transform were combined with amplitudes from electron diffraction patterns to reconstruct the projected mass density of the gp32*I crystal at 8.4 A resolution.

Crystallization↗
PubMed1979

A structural model for the kinetic behavior of hemoglobin.

The tertiary structures of all liganded hemoglobins in the R state differ in detail. Steric hindrance arising from nonbonded ligand-globin interactions affects the binding of ligands such as CO and cyanide which preferentially form linear axial complexes to heme; these ligands bind in a strained off-axis configuration. Ligands such as O2 and NO, which preferentially form bent complexes, encounter less steric hindrance and can bind in their (preferred) unstrained configuration. Linear complexes distort the ligand pockets in the R state (and by inference, in the T state) more than bent complexes. These structural differences between linear and bent complexes are reflected in the kinetic behavior of hemoglobin. Structural interpretation of this kinetic behavior indicates that the relative contributions of nonbonded ligand-globin interactions and nonbonded heme interactions to transition state free energies differ for linear and bent ligands. The relative contributions of these interactions to the free energy of cooperativity may also differ for linear and bent ligands. Thus the detailed molecular mechanism by which the affinity of heme is regulated differs for different ligands.

Allosteric Regulation↗