Research & Publications
Numerous bacteria use a rotating flagellar motor to drive the cell body and swim in liquid medium or swarm on solid surfaces, movements essential for bacterial survival and pathogenicity. The bacterial flagellar motor converts the electrochemical potential difference across the cell membrane into mechanical work and can rotate in both counterclockwise and clockwise directions. Understanding how the flagellar motor generates torque and switches its rotation direction can reveal fundamental properties of the bacterial life cycle. Our work has utilized cryo-ET analysis and revealed: 1) that torque generation requires conformational change of the C-ring in the flagellar motor; 2) the molecular mechanism for directional switching of the flagellar motor.
Bacteria exist mainly as planktonic organisms floating in suspensions or as adherent forms called biofilms. According to the National Institutes of Health (NIH), bacterial biofilms are responsible for up to 75% of infectious diseases in humans. Biofilm can be found almost everywhere, and the bacteria in the biofilm are protected from adverse environmental factors and host immune responses. Understanding the mechanisms of biofilm formation and antibiotic resistance have great importance for public health. We are now also utilizing cryo-FIB and cryo-ET analyses to study bacterial interactions and phage resistance in biofilms.
- Chang, Y., et al. Structural insights into flagellar stator-rotor interactions. Elife, 2019.
- Chang, Y., et al. Molecular mechanism for rotational switching of the bacterial flagellar motor. Nat Struct Mol Biol, 2020.
Flagella; Molecular Structure; Cryoelectron Microscopy; Host-Pathogen Interactions