Amanda Erwin, Graduate Student (M. Ohi laboratory), Life Sciences Institute and Department of Cell and Developmental Biology, University of Michigan

Helicobacter pylori is a bacterial strain that colonizes the stomach and contributes to the formation of stomach ulcers and gastric cancer. The bacterium secretes a toxin called VacA which increases its virulence by altering the normal functions of the cells that line the stomach as well as the immune cells that attempt to clear the bacteria. To further explore how this VacA toxin works, we determined its 3D structure, using single particle cryo-electron microscopy. This image represents one view from the 3D density map. It reveals that VacA assembles into hexamers that resemble beautiful snowflakes. This complex assembly appears to be necessary for VacA activity and may represent a pore-like complex that forms in cell membranes, altering cell physiology.

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