EBV Conference 2008 Guangzhou - Baylor College of Medicine

78 (RegID: 1226)
Raphele Germi
Institution: University Joseph Fourier/CHU de Grenoble
e-mail: rgermi@chu-grenoble.fr
THREE DIMENSIONAL STRUCTURE OF THE EPSTEIN-BARR VIRUS CAPSID
RAPHAELE GERMI, PATRICE MORAND, SYLVIE LARRAT, JOSETTE GUIMET, Geneviève GUY,
ROB RUIGROK, GUY SCHOEHN
Posterabstract:
The knowledge of EBV morphology is widely based on its homology with the others herpesviruses. The
common properties of HSV-1, CMV and HHV8 icosahedral capsid structure is a triangulation number of
T=16, 150 hexamers and 12 pentamers of the major capsid protein (VP5) and 320 triplex complexes
located on each of the local three-fold axis. The triplex complex is an heterotrimers alpha beta 2 (VP19C
and VP23). Here we report the 3D structure of the EBV capsid, reconstructed from electron
cryomicroscopy (cryoEM) images and show its structural similarities and differences with HHV8. Viruses
were produced in cells culture, concentrated and purified onto CsCl density gradient, localize by
negative-stain and cryo-EM was performed by using a LaB6 FEI CM200 microscope equipped with a
Gatan 626 cryoholder operated at 200 kV and 20,000x nominal magnification. The 500 best particles,
selected manually from 19 Kodak SO163 films digitised at a 7 祄 sampling step on a Z/I Imaging
PhotoScan, were used to calculate the 20 ?resolution. The 3D structure of the virus exhibit the T=16
triangulation number which characterize the herpesviridae family. The structure is very similar to the one
of HHV8, in size (1250 ?in diameter) but also in the different capsomer organization. The hexons, pentons
and the triplex capsomers are very similar in shape. There is anyway a big difference between all the
known structure of herpesviruses and our structure. Around the 5-fold axis of the EBV capsid, at the
expected position of the triplex protein, there is only a small density present. This is the first time that this
kind of phenomena is visible in the herpesviridae family.
EBV Conference 2008 Guangzhou
- 138 -