Figure: Schematic of Ebola virus protein associations (image from the cover of Cell, August 2013).
The group of Erica Saphire at The Scripps Research Institute specializes in understanding the molecular basis of viral pathogenesis. In a recent effort, they determined crystal structures of the Ebola virus matrix protein. Their study revises the standard molecular biology dogma that a protein adopts one structure for one function. They showed that the VP40 matrix protein of Ebola virus can rearrange into at least three structures for three separate and essential functions in the virus life cycle. A VP40 dimer traffics to the host cell membrane, a VP40 linear hexamer at the membrane forms a filamentous matrix that is critical for budding, and a VP40 octameric ring binds RNA to regulate viral transcription within infected cells. The discovery of multiple structures, together with virological and cellular studies that assigned a function to each structure, demonstrated how viruses can encode a large number of required protein functions in a surprisingly compact genome.
Citation: Bornholdt, ZA, Noda, T, Abelson, DM, Halfmann, P, Wood, MR, Kawaoka, Y, Saphire, EO. Structural Rearrangement of Ebola Virus VP40 Begets Multiple Functions in the Virus Life Cycle, Cell 154 (4), 763-774 (2013). DOI: 10.1016/j.cell.2013.07.015