Picture of the Week: Shiga-like toxin

Recently the University of Queensland ran the annual Molecular Design Contest, where students use pymol or related software to create a stunning image of a macromolecule of their choice. This is a contest I helped set up during my Masters degree at UQ, and I am happy to see it’s continuation by the School of Chemistry and Molecular Biosciences and the UQ Molecular Biotech Students Club. A huge congratulations to Vivek Narotam, a B.Sc student in the Faculty of Science who won this year’s competition with his rendering of a shiga-like toxin molecule (also known as verotoxin).

Vivek was inspired to make the beautiful image of the deadly shiga toxin (shown above) by the Shakespearean tragic play “Macbeth”, due to the ‘play’s themes of duplicity and how appearance does not necessarily reflect reality’. This is in reference to both the repeating structure of the shiga toxin protein which is comprised of 5 alpha-beta subunits in a pentamer, giving it the lovely snowflake-like appearance, despite how deadly the toxin is. Shiga toxins are made by bacteria the Shigatoxigenic group of E. coli (STEC), which includes the deadly serotype O157:H7. Shiga toxin exerts its effects on host cell protein synthesis, leading to severely compromised kidney function, damaged blood vessels and organ beds.

I am particularly pleased with shiga toxin being picked by the judges this year because of my previous interest in it. Back when I was an undergrad at the University of the Sunshine Coast, the Honors research project I designed was going to be elucidating the molecular mechanisms of shiga-like toxin leading to kidney pathophysiology seen in haemolytic uraemic syndrome. Anyway, join me in congratulating Vivek again; I wish him all the best for the rest of his studies!