A family of bacterial actin homologs forms a three-stranded tubular structure.

The cytoskeleton is crucial for cell organization and movement. In Eukaryotes, it largely consists of the protein actin, that forms a double-stranded linear filamentous structure in the presence of ATP and disassemble upon ATP hydrolysis. Bacteria also possess actin homologs, that drive fundamental cellular processes, including cell division, shape maintenance, and DNA segregation.

Structural Characterization of SARS-CoV-2: Where We Are, and Where We Need to Be.

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has rapidly spread in humans in almost every country, causing the disease COVID-19. Since the start of the COVID-19 pandemic, research efforts have been strongly directed towards obtaining a full understanding of the biology of the viral infection, in order to develop a vaccine and therapeutic approaches. In particular, structural studies have allowed to comprehend the molecular basis underlying the role of many of the SARS-CoV-2 proteins, and to make rapid progress towards treatment and preventive therapeutics.