Structure, Assembly, and Molecular Interactions of Filamentous Plant Viruses

Vanderbilt University, Nashville TN

Investigators

Abstract

This project encompasses the determination of the three-dimensional molecular structures of a number of flexible filamentous plant viruses. It is part of a comprehensive, integrated structural analysis of the filamentous plant viruses, aimed at explaining the processes of viral infection, dissemination, and host interactions, and understanding the relationships among these important viruses. The viruses to be studied include members of the potexvirus, potyvirus, and closterovirus groups. The potexviruses are of great significance as models for fundamental virology and cell biology; they have enormous potential in biotechnology, and they are of considerable importance for the damage they cause in agriculture. The potyviruses are responsible for half the viral crop damage in the world, and are of interest because of their close relationship to the animal rhinoviruses (responsible for such diverse conditions as the common cold, polio, and foot-and-mouth disease). The closteroviruses are also of major agricultural significance. To utilize the full potential of the flexible filamentous viruses as models and in biotechnology, and to combat their effects in agriculture, knowledge of three-dimensional structures in atomic detail is required. Apart from this group's preliminary results, there are no three-dimensional structures known for any flexible filamentous virus. Virus structures to be determined will include the most important of the potexviruses, potato virus X, as well as the potyviruses soybean mosaic virus and wheat streak mosaic virus and the closterovirus beet yellows virus. Structures will be determined by cryo-electron microscopy and X-ray fiber diffraction; models derived from cryo-electron microscopy will be used as starting points for more detailed analysis using fiber diffraction data. Fiber diffraction specimen preparation methods developed in this laboratory have greatly improved the quality of data from potexviruses and potyviruses; before this project began, no useful diffraction data had been obtained from potyviruses. Broader impacts will be through the integration of research and education, and through the application of this research to new developments in crop protection and plant biotechnology, particularly in the production of pharmacologically useful products. This laboratory has a strong program of involvement of undergraduates and K-12 teachers in research, and the project activities will include undergraduates, graduate students, and K-12 teachers and students.