We are investigating helical filamentous superstructures comprised from thousands of identical copies of monomeric or dimeric proteins. We are focusing on tubulin dimer, which assembles into microtubule (MT), and the flagellin monomer that assembles into flagella. 

MTs are a major component of the cytoskeletal protein’s arsenal and are essential to cell structure, cell division, motility, nerve, and axonal function. Mechanistic understanding at the molecular level, of cytoskeleton protein dynamics and how their regulation control cell biology is currently very limited. This requires structural information at high spatial and temporal resolution, which can be correlated to function. Our lab has developed methodologies to address and investigate the dynamic structures and functions of cytoskeleton proteins. 

Flagella are attached to a bacterial surface with a rotary molecular motor that powers high frequency flagellar rotation and the motility of the entire bacterium. We are using the unique properties of the flagellar filaments to engineer bulk materials with intriguing mechanical, flow, and sensing properties. Flagellar filaments can assume a number of distinct helical shapes. The flagellum can switch between multiple helical shapes in response to environmental conditions or an applied torque. Applying an extensional force to an individual flagellum can induce a polymorphic transition, resulting in nonmonotonic relationship between an applied stress and strain.