Diffraction studies of the particles of two closteroviruses: heracleum latent virus and heracleum virus 6.
X-ray diffraction from oriented specimens of purified preparations of particles of heracleum latent closterovirus (HLV) showed that they have a helical arrangement of protein subunits, and that the structure repeats in five helical turns in which there are 5q +/- 1 protein subunits, where q is an integer. The pitch of the helix was estimated to be 3.26 (+/- 0.10) nm. Optical diffraction patterns from electron micrographs of HLV particles give an estimated pitch of 3.3 (+/- 0.2) nm and show that the number of subunits in the repeat period is 5q-1, where q has a value of 8 or 9. Optical diffraction from electron micrographs of particles of a second closterovirus, heracleum virus 6, shows that they too have a helical structure which repeats in five turns, in which there are 5q +/- 1 protein subunits. The estimated pitch of the primary helix is 3.6 (+/- 0.2) nm, and the estimate of q is 9.
Tollin
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P
Department of Applied Physics and Electronic and Manufacturing Engineering, University of Dundee, U.K.
Wilson
H R
HR
Roberts
I M
IM
Murant
A F
AF
D008854:Microscopy, Electron; D010942:Plant Viruses / Q000648:ultrastructure*; D010944:Plants / Q000382:microbiology; D017365:Spices / Q000382:microbiology; D014771:Virion / Q000648:ultrastructure*; D014961:X-Ray Diffraction