Length-dependent flagellar growth of Vibrio alginolyticus revealed by real time fluorescent imaging
Feb. 12, 2017
Dr. Fan Bai published a paper on eLIFE with his collaborators.
Bacterial ?agella are extracellular ?laments that drive swimming in bacteria. During motor assembly, ?agellins are transported unfolded through the central channel in the ?agellum to the growing tip. Here, we applied in vivo ?uorescent imaging to monitor in real time the Vibrio alginolyticus polar ?agella growth. The ?agellar growth rate is found to be highly length-dependent. Initially, the ?agellum grows at a constant rate (50 nm/min) when shorter than 1500 nm. The growth rate decays sharply when the ?agellum grows longer, which decreases to ~9 nm/min at 7500 nm. We modeled ?agellin transport inside the channel as a one-dimensional diffusive process with an injection force at its base. When the ?agellum is short, its growth rate is determined by the loading speed at the base. Only when the ?agellum grows longer does diffusion of ?agellin become the rate-limiting step, dramatically reducing the growth rate. Our results shed new light on the dynamic building process of this complex extracellular structure.
Original link: https://elifesciences.org/content/6/e22140