Placement of the Structural Proteins in Sindbis Virus

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.

FOURIER-BESSEL method
Reference:
Baker, T. S., N. H. Olson, and S. D. Fuller (1999).
Adding the third dimension to virus life cycles:
Three-dimensional reconstruction of icosahedral
viruses from cryo-electron micrographs.
Micro. & Mol. Bio. Rev. 63:862-922.

each viral image was CTF corrected before reconstruction, based on the following equation: F(corr)=F(obs)/[|CTF|+wiener]

films were developed in full-strength of Kodak D19 developer for 12 minutes at 20 C

AMINO ACID BIOSYNTHESIS REGULATORY PROTEIN

Chains E-L contain alpha-carbons only.
The C-terminal residues of chains M-P
contain alpha-carbons only.

HETEROGEN
THE COORDINATES OF UNX 1139, 1141, 1245, 1196, 1200,
1262, 1318, 4139, 4141, 4245, 4196, 4200, 4262, 4318,
5139, 5141, 5245, 5196, 5200, 5262, 5318, 6139, 6141,
6245, 6196, 6200, 6262, 6318 ARE THE CENTERS OF
DIFFERENCE DENSITY PEAKS THAT CORRESPOND TO THE
CARBOHYDRATE MOLECULES OF THE VIRION.
THE COORDINATES OF UNX 1000, 4000, 5000, AND 6000
ARE THE POINTS WHERE THE GLYCOPROTEINS E1 AND E2
ENTERS INTO MEMBRANE.

icosahedral asymmetric unit, std point frame

Coat Protein C, GENERAL CONTROL PROTEIN GCN4, Glycoprotein E1
sindbis virus, alphavirus structure, glycoprotein organization, nucleocapsid structure, transmembrane coiled coils, Icosahedral virus, Virus