How the Ebola virus protects its hereditary information
Clamped genome: An extension from the nucleoprotein lobe (bottom) envelops the RNA (yellow) carrying the Ebola virus genome. (Image: John Briggs/EMBL; this image may only be used for reporting of the corresponding scientific publication.)
A research team from Marburg, Heidelberg and Kyoto elucidates the structure and assembly of the Ebola virus’ genome envelope. This envelope protects the epidemic pathogen’s genome from being broken down by human enzymes. The results of this structure analysis have been published in the current online issue of Nature.
Viruses such as those causing Ebola and Marburg fever contain genomes in the form of RNA molecules. As the affected host cells contain enzymes that break down these ribonucleic acids (RNA), the viruses protect their hereditary information with an envelope, the so-called nucleocapsid. “To date there have been no high-resolution reconstructions showing nucleocapsids in intact viruses of this virus family,” explains Prof Stephan Becker, virologist at the University of Marburg and Coordinator at the German Center for Infection Research (DZIF). His research group obtained the virus and the virus proteins that were used in the investigations. The structure analyses were predominantly conducted at the European Molecular Biology Laboratory in Heidelberg (EMBL), led by Dr John Briggs.
The scientists used a combination of crystal structure studies and electron microscopy to create high-resolution reconstructions of the genome’s protein envelope in intact cells for the first time. The data obtained showed what these nucleocapsid proteins look like and how the individual nucleoproteins are arranged to form the capsid.
The analysis shows a kind of clasp holding the RNA molecules: the nucleoprotein’s coil shaped end piece forms an extension which envelops and fixates the RNA molecule. The coil extension is also responsible for the assembly of the nucleoprotein. The findings of this investigation and the model of this assembly contribute to understanding how the virus replicates during infection.
This study was funded by the German Center for Infection Research amongst others.
