| Participant: | Freiberg, Alexander |
CRYO-ELECTRON MICROSCOPY AND SINGLE-PARTICLE AVERAGING OF RIFT VALLEY FEVER VIRUS
Alexander N Freiberg, Ph.D.1, M.B. Sherman, Ph.D. 2, S.J. Watowich, Ph.D. 2, and M.R. Holbrook, Ph.D. 1
Departments of 1Pathology, 2Biochemistry and Molecular Biology, UTMB
Background: Rift Valley fever (RVF) is a serious viral disease of animals and humans that occurs throughout sub-Saharan Africa, Egypt, and the Arabian Peninsula. Objective: The aim of this study is to determine the three-dimensional (3D) structure of RVFV vaccine strain MP-12 (RVFV MP-12) using single-particle cryo-electron microscopy. Methods: Using a single-particle image processing approach, we generated a 27 Å resolution 3D map of RVFV MP-12. Results: Our 3D model revealed new structural features of the glycoprotein capsomers and allowed clear identification of protein densities located close to the lipid envelope, interconnecting capsomers with each other. Conclusions: The reconstruction demonstrates that members of the Phlebovirus genus, and perhaps all bunyaviruses, assemble into icosahedral particles, contrary to the previously accepted belief that these viruses are pleomorphic. The structure provides a detailed model for the morphology of phleboviruses and opens new avenues for high-resolution structural studies of the bunyavirus family. Furthermore, the structure might be helpful for the rational design of vaccines or antiviral therapeutics. This project was supported by a training fellowship from the W.M. Keck Foundation to the Gulf Coast Consortia through the Keck Center for Virus Imaging.