11.04.2024 First fractal molecule in nature discovered
An international research team from Max Planck Institute and SYNMIKRO publishes results in "Nature", involving two MiNu PIs.
An international team of researchers led by groups from the Max Planck Institute and the Center for Synthetic Microbiology has found the first regular molecular fractal in nature. They discovered a microbial enzyme - citrate synthase from a cyanobacterium - that spontaneously assembles into a regular fractal pattern known as the Sierpiński triangle. This is an infinitely repeating series of triangles made up of smaller triangles. Electron microscopy and evolutionary biochemistry studies indicate that this fractal may represent an evolutionary accident.
"We stumbled on this structure completely by accident and almost couldn’t believe what we saw when we first took images of it using an electron microscope," says first author Franziska Sendker. "The protein makes these beautiful triangles and as the fractal grows, we see these larger and larger triangular voids in the middle of them, which is totally unlike any protein assembly we’ve ever seen before."
How did this unusual exception emerge? What distinguishes the enzyme from all others, causing it to form a fractal shape? Teaming up with structural biologists at the university of Marburg, the team eventually managed to determine the molecular structure of this assembly using electron microscopy, which illuminated how it achieves its fractal geometry. "This was one of the harder, but also more fascinating structures I have solved in my career," says Jan Schuller, whose group helped determine the structure. "The problem with determining the structure of a fractal is that our image averaging techniques kept getting confused by the fact that the smaller triangles can be substructures of larger triangles. The algorithm kept homing in on these smaller triangles instead of seeing the larger structures they were part of."
Click here to read the full article on the main page of the University of Marburg.
The PIs of GRK 2937's Projects 1 and 4, Gert Bange and Jan Schuller, were involved in the publication: Emergence of fractal geometries in the evolution of a metabolic enzyme; Sendker, F. L.; Lo, J. K.; Heimerl, T.; Bohn, S.; Persson, L-J.; Mais, C.N.; Sadowska, W.; Paczia, N.; Nußbaum, E.; del Carmen Sánchez Olmos, M.; Forchhammer. K.; Schindler, D.; Erb, T. J.; Benesch, J. L. P.; Marklund, E.; Bange, G.; Schuller, J. M.; Hochberg, G. K. A.; Nature (2024) DOI: 10.1038/s41586-024-07287-2