scholarly journals Cryoelectron-Microscopy Image Reconstruction of Symmetry Mismatches in Bacteriophage φ29

2001 ◽  
Vol 135 (1) ◽  
pp. 38-46 ◽  
Author(s):  
Marc C. Morais ◽  
Yizhi Tao ◽  
Norman H. Olson ◽  
Shelley Grimes ◽  
Paul J. Jardine ◽  
...  
Keyword(s):  
Image Reconstruction ◽  
Cryoelectron Microscopy ◽  
Microscopy Image

scholarly journals Structures of bovine and human papillomaviruses. Analysis by cryoelectron microscopy and three-dimensional image reconstruction

1991 ◽  
Vol 60 (6) ◽  
pp. 1445-1456 ◽  
Author(s):  
T.S. Baker ◽  
W.W. Newcomb ◽  
N.H. Olson ◽  
L.M. Cowsert ◽  
C. Olson ◽  
...  
Keyword(s):  
Image Reconstruction ◽  
Three Dimensional ◽  
Human Papillomaviruses ◽  
Cryoelectron Microscopy ◽  
Dimensional Image

scholarly journals Image Reconstructions of Microtubules Decorated with Monomeric and Dimeric Kinesins: Comparison with X-Ray Structure and Implications for Motility

1998 ◽  
Vol 141 (2) ◽  
pp. 419-430 ◽  
Author(s):  
A. Hoenger ◽  
S. Sack ◽  
M. Thormählen ◽  
A. Marx ◽  
J. Müller ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Image Reconstruction ◽  
Three Dimensional ◽  
Coiled Coil ◽  
Cryoelectron Microscopy ◽  
Short Neck ◽  
X Ray ◽  
Dimensional Image ◽  
Tubulin Subunit ◽  
Image Reconstructions

We have decorated microtubules with monomeric and dimeric kinesin constructs, studied their structure by cryoelectron microscopy and three-dimensional image reconstruction, and compared the results with the x-ray crystal structure of monomeric and dimeric kinesin. A monomeric kinesin construct (rK354, containing only a short neck helix insufficient for coiled-coil formation) decorates microtubules with a stoichiometry of one kinesin head per tubulin subunit (α–β-heterodimer). The orientation of the kinesin head (an anterograde motor) on the microtubule surface is similar to that of ncd (a retrograde motor). A longer kinesin construct (rK379) forms a dimer because of the longer neck helix forming a coiled-coil. Unexpectedly, this construct also decorates the microtubule with a stoichiometry of one head per tubulin subunit, and the orientation is similar to that of the monomeric construct. This means that the interaction with microtubules causes the two heads of a kinesin dimer to separate sufficiently so that they can bind to two different tubulin subunits. This result is in contrast to recent models and can be explained by assuming that the tubulin–kinesin interaction is antagonistic to the coiled-coil interaction within a kinesin dimer.

scholarly journals Mathematical modeling for 2D light-sheet fluorescence microscopy image reconstruction

2020 ◽  
Vol 36 (7) ◽  
pp. 075005
Author(s):  
Evelyn Cueva ◽  
Matias Courdurier ◽  
Axel Osses ◽  
Victor Castañeda ◽  
Benjamin Palacios ◽  
...  
Keyword(s):  
Mathematical Modeling ◽  
Image Reconstruction ◽  
Fluorescence Microscopy ◽  
Light Sheet ◽  
Microscopy Image ◽  
Light Sheet Fluorescence Microscopy

scholarly journals Early steps in reovirus infection are associated with dramatic changes in supramolecular structure and protein conformation: analysis of virions and subviral particles by cryoelectron microscopy and image reconstruction

1993 ◽  
Vol 122 (5) ◽  
pp. 1023-1041 ◽  
Author(s):  
KA Dryden ◽  
G Wang ◽  
M Yeager ◽  
ML Nibert ◽  
KM Coombs ◽  
...  
Keyword(s):  
Image Reconstruction ◽  
Conformational Change ◽  
Protein Conformation ◽  
Cell Attachment ◽  
Environmental Stability ◽  
Cryoelectron Microscopy ◽  
Reovirus Infection ◽  
Sigma 1 ◽  
Outer Capsid ◽  
Subviral Particles

Three structural forms of type 1 Lang reovirus (virions, intermediate subviral particles [ISVPs], and cores) have been examined by cryoelectron microscopy (cryoEM) and image reconstruction at 27 to 32-A resolution. Analysis of the three-dimensional maps and known biochemical composition allows determination of capsid protein location, globular shape, stoichiometry, quaternary organization, and interactions with adjacent capsid proteins. Comparisons of the virion, ISVP and core structures and examination of difference maps reveal dramatic changes in supra-molecular structure and protein conformation that are related to the early steps of reovirus infection. The intact virion (approximately 850-A diam) is designed for environmental stability in which the dsRNA genome is protected not only by tight sigma 3-mu 1, lambda 2-sigma 3, and lambda 2-mu 1 interactions in the outer capsid but also by a densely packed core shell formed primarily by lambda 1 and sigma 2. The segmented genome appears to be packed in a liquid crystalline fashion at radii < 240 A. Depending on viral growth conditions, virions undergo cleavage by enteric or endosomal/lysosomal proteases, to generate the activated ISVP (approximately 800-A diam). This transition involves the release of an outer capsid layer spanning radii from 360 to 427 A that is formed by 60 tetrameric and 60 hexameric clusters of ellipsoidal subunits of sigma 3. The vertex-associated cell attachment protein, sigma 1, also undergoes a striking change from a poorly visualized, more compact form, to an extended, flexible fiber. This conformational change may maximize interactions of sigma 1 with cell surface receptors. Transcription of viral mRNAs is mediated by the core particle (approximately 600-A diam), generated from the ISVP after penetration and uncoating. The transition from ISVP to core involves release of the 12 sigma 1 fibers and the remaining outer capsid layer formed by 200 trimers of rod-shaped mu 1 subunits that span radii from 306 to 395 A. In the virion and ISVP, flower-shaped pentamers of the lambda 2 protein are centered at the vertices. In the ISVP-to-core transition, domains of the lambda 2 subunits rotate and swing upward and outward to form a turret-like structure extending from radii 305 to 400 A, with a diameter of 184 A, and a central channel 84 A wide. This novel conformational change allows the potential diffusion of substrates for transcription and exit of newly synthesized mRNA segments.(ABSTRACT TRUNCATED AT 400 WORDS)

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