Placement of the Structural Proteins in Sindbis Virus
ELECTRON MICROSCOPY
Sample
Sindbis Virus
Specimen Preparation
Sample Aggregation State
PARTICLE
3D Reconstruction
Reconstruction Method
SINGLE PARTICLE
Number of Particles
Reported Resolution (Å)
11.4
Resolution Method
Other Details
Refinement Type
Symmetry Type
POINT
Point Symmetry
I
Map-Model Fitting and Refinement
Id
1 (1SVB, 1YSA, 1I9W)
Refinement Space
REAL
Refinement Protocol
Refinement Target
Overall B Value
1000
Fitting Procedure
Details
DETAILS--The structure of the lipid-enveloped Sindbis virus has been determined
by fitting atomic resolution crystallographic structures of component ...
DETAILS--The structure of the lipid-enveloped Sindbis virus has been determined
by fitting atomic resolution crystallographic structures of component proteins
into an 11 resolution cryo- electron microscopy (cryoEM) map (with significant
terms to 10 resolution). The E1 glycoprotein, whose structure had been
determined independently for the homologous Semliki Forest virus by X-ray
crystallography (Lescar, J., Roussel,A., Wein, M.W., Navaza, J., Fuller, S.D.,
Wengler, G., and Rey, F.A. (2001). The fusion glycoprotein shell of Semliki
Forest virus- an icosahedral assembly primed for fusogenic activation at
endosomal pH. Cell 105, 137-148), was fitted into the cryoEM density, in part
by using the known positions of glycoprotein sites as restraints. The
well-resolved transmembrane regions form coiled coils that could be fitted with
the dimeric GCN4 coiled-coil structure. The helices could be seen to extend to
E1 and E2 on the outside of the membrane and to the nucleocapsid on the inside.
The known structure of the capsid protein (Choi, H.K., Tong, L., Minor, W.,
Dumas, P., Boege, U., Rossmann, M.G., and Wengler, G. (1991). Structure of
Sindbis virus core protein reveals a chymotrypsin-like serine proteinase and
the organization of the virion. Nature 354, 37-43.) was fitted into the density
corresponding to the nucleocapsid, revising an earlier published structure.
Data Acquisition
Detector Type
KODAK SO-163 FILM
Electron Dose (electrons/Å**2)
18.4
Imaging Experiment
1
Date of Experiment
2000-06-15
Temperature (Kelvin)
87
Microscope Model
FEI/PHILIPS CM200T
Minimum Defocus (nm)
1100
Maximum Defocus (nm)
2580
Minimum Tilt Angle (degrees)
Maximum Tilt Angle (degrees)
Nominal CS
2
Imaging Mode
BRIGHT FIELD
Specimen Holder Model
Nominal Magnification
38000
Calibrated Magnification
Source
FIELD EMISSION GUN
Acceleration Voltage (kV)
200
Imaging Details
EM Software
Task
Software Package
Version
MODEL FITTING
EMfit
RECONSTRUCTION
EM3DR
Image Processing
CTF Correction Type
CTF Correction Details
Number of Particles Selected
Particle Selection Details
each viral image was CTF corrected before reconstruction, based on the following equation: F(corr)=F(obs)/[|CTF|+wiener]
