More than two decades ago, scientists discovered the Arp2/3 complex, an actin (cellular protein) cytoskeketal nucleator that plays a crucial role in cell division, immune response, neurodevelopment, and other biological processes. But the structure of the activated state of the complex had not been determined until now, an achievement that may lay the foundation for uncovering its role in biology and the development of disease.

Using cryogenic electron microscopy (cryo-EM), Mohammed and his team were able to obtain a high-resolution snapshot of the actin filaments at birth by solving the structure of the activated actin nucleator, the Arp2/3 complex, in the process of nucleating an actin filament.

The idea, approach, and methodology were unique. Moreover, solving this fundamental question granted the field a better understanding of how actin nucleation starts. This will help both basic and therapeutic research to tackle more advanced questions and pathologies associated with turnover of actin filaments.