The three-dimensional structure of frozen-hydrated left- and right-handed forms of bacterial flagellar filaments from an identical serotype

1986 ◽  
Vol 44 ◽  
pp. 298-299
Author(s):  
S. Trachtenberg ◽  
D. J. DeRosier
Keyword(s):  
Ionic Strength ◽  
Basal Body ◽  
Three Dimensional ◽  
Dimensional Structure ◽  
Protein Species ◽  
Liquid Environment ◽  
Bacterial Flagellum ◽  
Left And Right ◽  
Rotary Motor ◽  
Helical Parameters

The bacterial cell is propelled through the liquid environment by means of one or more rotating flagella. The bacterial flagellum is composed of a basal body (rotary motor), hook (universal coupler), and filament (propellor). The filament is a rigid helical assembly of only one protein species — flagellin. The filament can adopt different morphologies and change, reversibly, its helical parameters (pitch and hand) as a function of mechanical stress and chemical changes (pH, ionic strength) in the environment.

Three-dimensional reconstruction of the bacterial basal body/switch complex by electron cryomicroscopy

1992 ◽  
Vol 50 (1) ◽  
pp. 514-515
Author(s):  
Noreen R. Francis ◽  
Gina E. Sosinsky ◽  
Dennis Thomas ◽  
David J. DeRosier
Keyword(s):  
Basal Body ◽  
Three Dimensional ◽  
Structural Proteins ◽  
Three Dimensional Reconstruction ◽  
Electron Cryomicroscopy ◽  
Clockwise Rotation ◽  
Bacterial Flagellum ◽  
Dimensional Reconstruction ◽  
Rotary Motor

The bacterial flagellum is unique among Nature's motors in that it posesses a reversible, rotary motor and a propeller that converts torque into thrust The basal body, that part of the flagellum isolated from cells in attempts to purify the motor, contains eight different structural proteins. In Salmonella typhimurimi, the basal body consists of four rings (denoted M, S, L, and P) threaded on a coaxial rod. The M-S, L and Prings are each composed of a different protein, FliF, FlgH, and Flgl, each of which is present in ∽26 copies. The rod contains four different proteins, FlgB, FlgC, FlgF, and FlgG. Also present is FliE. These all are present in ∽6 copies except for FlgG present in ∽26 copies. The proteins important for motor rotation, however, are missing in standard basal body preparations. These missing proteins include the three “switch” proteins, FliG, FliM, and FliN, which control motor reversal (clockwise and counter-clockwise rotation) and may correspond to the rotor and gearbox of the motor. FliG has recently been shown to be localized at the M ring.

The Structure and Subunit Organization of the Bacterial Flagellar Motor by Scanning Transmission Electron Microscopy and Cryoelectron Microscopy

1990 ◽  
Vol 48 (1) ◽  
pp. 278-279
Author(s):  
Gina E. Sosinsky ◽  
Noreen R. Francis ◽  
Charles D. DeRosier ◽  
David J. DeRosier ◽  
James Hainfeld ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Basal Body ◽  
Three Dimensional ◽  
Dimensional Structure ◽  
Cryoelectron Microscopy ◽  
Data Set ◽  
Bacterial Flagellum ◽  
The Individual ◽  
The Masses ◽  
Subunit Organization

The bacterial flagellum is unique in having a rotary motor. In Salmonella typhimurium, the basal body, a component of the motor, consists of four rings (denoted M, S, L, and P) threaded on a coaxial rod. The M, L, and P rings are each composed of a different protein: FliF=61 kD, FlgH=22 kD, and FlgI=36 kD, respectively. The rod contains at least four different proteins: FlgB=15 kD, FlgC=14 kD, FlgF=26 kD, and FlgG=28 kD. Using quantitative gel analysis, Jones et al. estimated that there are about 26 copies of FlgG, FlgH, Flgl and FliF, and 6 copies of FlgB, FlgC and FlgF per basal body. The total mass of these 7 proteins per basal body is ∽4200 kD. There appear to be additional proteins in the basal body, but their locations and amounts are not known. Our aim is to produce subcomplexes of the basal body and determine their structures and masses using electron microscopy. This approach is complementary to that of Jones et al. and can reveal the presence and amounts of as yet unidentified components. We find, in pH3- or pH4-treated preparations of basal bodies, four subcomplexes of the hook basal body complex (HBB): the HLPRS (hook, L and P rings on the distal rod, proximal rod, S ring); the HLPR (lacks the M and S rings), the HLP (lacks the M, S, and proximal rod); and the LP complex (Figs. 1 and 2). We have been able to visualize the three-dimensional structure and the subunit organization using the combined techniques of cryoelectron microscopy and image analysis. These studies suggest that the S ring is a separate component from the rod or M ring and that the rod consists of two sections. Because the different sub-complexes are distinguishable in a field of particles, we measured the molecular masses of the individual subcomplexes using the Brookhaven STEM even though these preparations are not homogeneous (Fig. 3). All the structures analyzed so far had hooks attached. We measured the length and mass/length from STEM images and then subtracted the mass of the hook. Preliminary results show that the molecular mass of the hookless basal body is 4400−500 kD (n=165), that of the LP-rod (proximal and distal) is 3500±300 kD (n=52), and that of the LP-distal rod is 2300±450 kD (n=76) (Fig. 4). The difference between these three molecular weights gives estimates of the mass of the M and S rings (4400 - 3500 = 900 kD) and proximal rod, 3500 − 2300 = 1200 kD. The mass of the M and S rings may be underestimated due to the undetected presence of HLPRS subcomplexes in the basal body data set. We are presently measuring and re-evaluating masses for the subcomplexes in order to get more accurate estimates of the masses and numbers of subunits.

Conformational Transitions in Escherichia coli Ribosomal RNAs as Visualized by Dedicated STEM

1988 ◽  
Vol 46 ◽  
pp. 176-177
Author(s):  
J.S. Wall ◽  
V. Maridiyan ◽  
S. Tumminia ◽  
J. Hairifeld ◽  
M. Boublik
Keyword(s):  
Ionic Strength ◽  
Three Dimensional ◽  
Conformational Transitions ◽  
Dark Field ◽  
Dimensional Structure ◽  
Ribosomal Rnas ◽  
Field Mode ◽  
Freeze Dried ◽  
High Resolution Images ◽  
Low Ionic Strength

The high contrast in the dark-field mode of dedicated STEM, specimen deposition by the wet film technique and low radiation dose (1 e/Å2) at -160°C make it possible to obtain high resolution images of unstained freeze-dried macromolecules with minimal structural distortion. Since the image intensity is directly related to the local projected mass of the specimen it became feasible to determine the molecular mass and mass distribution within individual macromolecules and from these data to calculate the linear density (M/L) and the radii of gyration.2 This parameter (RQ), reflecting the three-dimensional structure of the macromolecular particles in solution, has been applied to monitor the conformational transitions in E. coli 16S and 23S ribosomal RNAs in solutions of various ionic strength.In spite of the differences in mass (550 kD and 1050 kD, respectively), both 16S and 23S RNA appear equally sensitive to changes in buffer conditions. In deionized water or conditions of extremely low ionic strength both appear as filamentous structures (Fig. la and 2a, respectively) possessing a major backbone with protruding branches which are more frequent and more complex in 23S RNA (Fig. 2a).

scholarly journals Structure of the native supercoiled flagellar hook as a universal joint

2019 ◽  
Vol 10 (1) ◽  
Author(s):  
Takayuki Kato ◽  
Fumiaki Makino ◽  
Tomoko Miyata ◽  
Péter Horváth ◽  
Keiichi Namba
Keyword(s):  
Image Analysis ◽  
Basal Body ◽  
Single Particle ◽  
Particle Image ◽  
Three Dimensional ◽  
Universal Joint ◽  
Density Map ◽  
Smoke Ring ◽  
Intersubunit Interactions ◽  
Rotary Motor

AbstractThe Bacterial flagellar hook is a short supercoiled tubular structure made from a helical assembly of the hook protein FlgE. The hook acts as a universal joint that connects the flagellar basal body and filament, and smoothly transmits torque generated by the rotary motor to the helical filament propeller. In peritrichously flagellated bacteria, the hook allows the filaments to form a bundle behind the cell for swimming, and for the bundle to fall apart for tumbling. Here we report a native supercoiled hook structure at 3.6 Å resolution by cryoEM single particle image analysis of the polyhook. The atomic model built into the three-dimensional (3D) density map reveals the changes in subunit conformation and intersubunit interactions that occur upon compression and extension of the 11 protofilaments during their smoke ring-like rotation. These observations reveal how the hook functions as a dynamic molecular universal joint with high bending flexibility and twisting rigidity.

scholarly journals THE THREE-DIMENSIONAL STRUCTURE OF THE BASAL BODY FROM THE RHESUS MONKEY OVIDUCT

1972 ◽  
Vol 54 (2) ◽  
pp. 246-265 ◽  
Author(s):  
Richard G. W. Anderson
Keyword(s):  
Basal Body ◽  
Three Dimensional ◽  
Longitudinal Axis ◽  
Scale Model ◽  
Dimensional Structure ◽  
Transverse Axis ◽  
Longitudinal Edge ◽  
Striated Rootlet ◽  
Basal Foot ◽  
Base View

The structure of the oviduct basal body has been reconstructed from serial, oblique, and tangential sections This composite information has been used to construct a three-dimensional scale model of the organelle The walls are composed of nine equally spaced sets of three tubules, which run from base to apex pitched to the left at a 10°–15° angle to the longitudinal axis. The transverse axis of each triplet set at its basal end intersects a tangent to the lumenal circumference of the basal body at a 40° angle (triplet angle). As the triplet set transverses from base to apex, it twists toward the lumen on the longitudinal axis of the inner A tubule; therefore, the triplet angle is 10° at the basal body-cilium junction. Strands of fibrous material extend from the basal end of each triplet to form a striated rootlet. A pyramidal basal foot projects at right angles from the midregion of the basal body. In the apex, a 175 mµ long trapezoidal sheet is attached to each triplet set. The smaller of the two parallel sides is attached to all three tubules while the longitudinal edge (one of the equidistant anti-parallel sides) is attached to the C tubule. The sheet faces counterclockwise (apex to base view) and gradually unfolds from base to apex; the outside corner merges with the cell membrane.

scholarly journals Three dimensional structure of FliI hexameric ring, export engine of the bacterial flagellum

2003 ◽  
Vol 43 (supplement) ◽  
pp. S107
Author(s):  
H. Suzuki ◽  
T. Minamino ◽  
K. Yonekura ◽  
K. Namba
Keyword(s):  
Three Dimensional ◽  
Dimensional Structure ◽  
Three Dimensional Structure ◽  
Bacterial Flagellum

scholarly journals Investigation of Three-Dimensional Structure and Pigment Surrounding Environment of a TiO2 Containing Waterborne Paint

Materials ◽  
2019 ◽  
Vol 12 (3) ◽  
pp. 464 ◽  
Author(s):  
Fei Yang ◽  
Bo Chen ◽  
Teruo Hashimoto ◽  
Yongming Zhang ◽  
George Thompson ◽  
...  
Keyword(s):  
Paint Film ◽  
3D Structure ◽  
Three Dimensional ◽  
Dimensional Structure ◽  
Systematic Research ◽  
Coating Films ◽  
Liquid Environment ◽  
Tio2 Particles ◽  
Surrounding Environment ◽  
Tio2 Pigment

Serial block-face scanning electron microscopy (SBFSEM) has been used to investigate the three-dimensional (3D) structure of a cured waterborne paint containing TiO2 pigment particles, and the surrounding environment of the TiO2 pigment particles in the cured paint film was also discussed. The 3D spatial distribution of the particles in the paint film and their degree of dispersion were clearly revealed. More than 55% of the measured TiO2 particles have volumes between 1.0 × 106 nm3 and 1.0 × 107 nm3. From the obtained 3D images, we proposed that there are three different types of voids in the measured cured waterborne paint film: voids that exist in the cured paint themselves, voids produced by particle shedding, and voids produced by quasi-liquid phase evaporation during measurement. Among these, the latter two types of voids are artefacts caused during SBFSEM measurement which provide evidence to support that the pigment particles in the cured paint/coating films are surrounding by quasi-liquid environment rather than dry solid environment. The error caused by particle shedding to the statistical calculation of the TiO2 particles was corrected in our analysis. The resulting 3D structure of the paint, especially the different voids are important for further systematic research, and are critical for understanding the real environment of the pigment particles in the cured paint films.

scholarly journals Three-dimensional structure of basal body triplet revealed by electron cryo-tomography

2011 ◽  
Vol 31 (3) ◽  
pp. 552-562 ◽  
Author(s):  
Sam Li ◽  
Jose-Jesus Fernandez ◽  
Wallace F Marshall ◽  
David A Agard
Keyword(s):  
Basal Body ◽  
Three Dimensional ◽  
Dimensional Structure ◽  
Three Dimensional Structure

Conformation of Ribosomes from Escherichia Coli

1974 ◽  
Vol 32 ◽  
pp. 210-211
Author(s):  
M. Boublik ◽  
W. Hellmann ◽  
F. Jenkins
Keyword(s):  
Binding Sites ◽  
Ribosomal Proteins ◽  
Fluorescent Dyes ◽  
Protein Biosynthesis ◽  
Three Dimensional ◽  
Spatial Arrangement ◽  
Dimensional Structure ◽  
Complete Understanding ◽  
And Function

The present knowledge of the three-dimensional structure of ribosomes is far too limited to enable a complete understanding of the various roles which ribosomes play in protein biosynthesis. The spatial arrangement of proteins and ribonuclec acids in ribosomes can be analysed in many ways. Determination of binding sites for individual proteins on ribonuclec acid and locations of the mutual positions of proteins on the ribosome using labeling with fluorescent dyes, cross-linking reagents, neutron-diffraction or antibodies against ribosomal proteins seem to be most successful approaches. Structure and function of ribosomes can be correlated be depleting the complete ribosomes of some proteins to the functionally inactive core and by subsequent partial reconstitution in order to regain active ribosomal particles.

Three-Dimensional Reconstruction Using Stereo Pairs from Serial Thick Sections

1977 ◽  
Vol 35 ◽  
pp. 562-563
Author(s):  
Robert Glaeser ◽  
Thomas Bauer ◽  
David Grano
Keyword(s):  
Three Dimensional ◽  
Dimensional Structure ◽  
Serial Sections ◽  
Thin Sections ◽  
3 Dimensional ◽  
Transmission Electron ◽  
Freeze Dried ◽  
Dimensional Reconstruction ◽  
Stereo Imagery ◽  
Whole Mounts

In transmission electron microscopy, the 3-dimensional structure of an object is usually obtained in one of two ways. For objects which can be included in one specimen, as for example with elements included in freeze- dried whole mounts and examined with a high voltage microscope, stereo pairs can be obtained which exhibit the 3-D structure of the element. For objects which can not be included in one specimen, the 3-D shape is obtained by reconstruction from serial sections. However, without stereo imagery, only detail which remains constant within the thickness of the section can be used in the reconstruction; consequently, the choice is between a low resolution reconstruction using a few thick sections and a better resolution reconstruction using many thin sections, generally a tedious chore. This paper describes an approach to 3-D reconstruction which uses stereo images of serial thick sections to reconstruct an object including detail which changes within the depth of an individual thick section.

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