20240412 GERMANY BACTERIAL PROTEIN FORMS SIERPINSKI TRIANGLE

Cryo-electron-microscopy structures of citrate synthase from the cyanobacterium Synechococcus elongatus, an enzyme that self-assembles into a genuine Sierpinski triangle, the first known natural example of a protein assembling into a fractal, a pattern previously seen only in engineered synthetic systems. Published in Nature in 2024 by a German-led team spanning Helmholtz Munich, Marburg, the Max Planck Institute for Terrestrial Microbiology and Tubingen, the structure builds hexameric units into 18-mer and 54-mer assemblies whose dihedral angles (60 degrees and 34 degrees) were measured directly from the cryo-EM data; ancestral-sequence reconstruction suggests the fractal shape emerged as a harmless evolutionary accident rather than a selected trait.

The card

• Date — 12 April 2024
• Where — Helmholtz Munich, with Philipps-University Marburg, the Max Planck Institute for Terrestrial Microbiology, and Tubingen University, Germany. 48.1351, 11.5820 — approximate
• Evidence grade — WEB-PHOTO

Sources

• nature.com
• rcsb.org

Works Cited

• Source, Title, Publisher, Year.