Homology model of E3 protein of Venezuelan Equine Encephalitis Virus TC-83 strain fitted with a cryo-EM map
4.4 angstrom cryo-EM structure of an enveloped alphavirus Venezuelan equine encephalitis virus.
METHOD--rigid-body fitting DETAILS--The E3 homology model was not further refined against the cryo-EM density map due to its less-resolved quality
After each iteration, the non-icosahedral parts (which included the lipids and the RNA) in the reconstruction were removed by a soft-edged mask derived from an icosahedrally organized, protein-only map that was low-pass filtered to 30 Angstroms. This map then served as the reference model for the next iteration.
CTF parameters were determined from particles within each CCD image
The virus contains 240 copies of E1, E2, E3 and capsid proteins
Venezuelan Equine Encephalitis Virus TC83 strain E3 protein that is cleaved from p62 protein
objective lens astigmatism was corrected at 100,000 times magnification
two of the eight grids used for imaging contained continuous carbon film underneath the samples
vitrification carried out in Chiu lab, Houston, TX
2 blots, each blot 2 second before plunging, offset = 0
purified from infected Baby hamster kidney (BHK) cells
A cubic portion of the original 3D density map of VEEV (covering one asymmetric unit)
the non-icosahedrally averaged cryo-EM density maps of VEEV
icosahedral asymmetric unit, std point frame