State-of-the-art imaging and image processing offer new insights into Herpes simplex virus
High resolution cryomicroscopy at eBIC bags more data on a virulent human pathogen
The structure of Herpes Simplex Virus (HSV) has been the subject of Electron cryomicroscopy (CryoEM) investigations for more than 30 years. Details of one particularly important area have, until now, proven elusive. Herpes virus particles have a portal-vertex structure, a molecular motor through which the viral genome is injected into the nucleus of new host cells. After infection, the portal is also used when the virus replicates, allowing the transfer of viral material into a new viral shell (capsid), which will then be used to infect more host cells.
Herpes: a global issue
eBic: state-of-the-art cryoimaging
“I love coming to Diamond! The support from the eBIC team is very good, we can just turn up with prepared samples and the eBIC scientists will set up the experiments for us. In fact, we can send prepared samples instead of visiting ourselves, and we have done that on occasions, and collected the data remotely. The expertise at eBIC is first rate – if you have a good sample, you’re assured of good data.”
Dr Bhella used cryogenic electron microscopy (cryoEM) to capture 3,702 micrographs, from which a dataset of 6,069 virion image was extracted. He then applied a novel image-processing approach to determine the structure of the portal-vertex. The results show the structure of the HSV portal-vertex at subnanometer resolution, which has led to a number of new discoveries, including the presence of two previously unknown structures associated with the portal-vertex. The 3D reconstruction also shows that one end of the viral genome extends outside the portal, which has previously only been seen in bacteriophages, not eukaryote viruses.
Scottish Centre for Macromolecular Imaging (SCMI)
The new SCMI is very similar to eBIC, and has been setup to expand the opportunities for CryoEM in Scotland. You can read more about it on BBC News online. Dr Bhella will continue his work on the HSV portal-vertex, investigating the new features he has discovered and continuing to develop computational techniques that will enable researchers to make the most of future resolution improvements.