ジャーナル: Nature / 年: 2024 タイトル: Emergence of fractal geometries in the evolution of a metabolic enzyme. 著者: Franziska L Sendker / Yat Kei Lo / Thomas Heimerl / Stefan Bohn / Louise J Persson / Christopher-Nils Mais / Wiktoria Sadowska / Nicole Paczia / Eva Nußbaum / María Del Carmen Sánchez ...著者: Franziska L Sendker / Yat Kei Lo / Thomas Heimerl / Stefan Bohn / Louise J Persson / Christopher-Nils Mais / Wiktoria Sadowska / Nicole Paczia / Eva Nußbaum / María Del Carmen Sánchez Olmos / Karl Forchhammer / Daniel Schindler / Tobias J Erb / Justin L P Benesch / Erik G Marklund / Gert Bange / Jan M Schuller / Georg K A Hochberg / 要旨: Fractals are patterns that are self-similar across multiple length-scales. Macroscopic fractals are common in nature; however, so far, molecular assembly into fractals is restricted to synthetic ...Fractals are patterns that are self-similar across multiple length-scales. Macroscopic fractals are common in nature; however, so far, molecular assembly into fractals is restricted to synthetic systems. Here we report the discovery of a natural protein, citrate synthase from the cyanobacterium Synechococcus elongatus, which self-assembles into Sierpiński triangles. Using cryo-electron microscopy, we reveal how the fractal assembles from a hexameric building block. Although different stimuli modulate the formation of fractal complexes and these complexes can regulate the enzymatic activity of citrate synthase in vitro, the fractal may not serve a physiological function in vivo. We use ancestral sequence reconstruction to retrace how the citrate synthase fractal evolved from non-fractal precursors, and the results suggest it may have emerged as a harmless evolutionary accident. Our findings expand the space of possible protein complexes and demonstrate that intricate and regulatable assemblies can evolve in a single substitution.