Stern, AlanBerg, Howard2014-06-182013Stern, Alan S., and Howard C. Berg. 2013. Single-File Diffusion of Flagellin in Flagellar Filaments. Biophysical Journal 105, no. 1: 182–184.0006-34951542-0086http://nrs.harvard.edu/urn-3:HUL.InstRepos:12336269A bacterial flagellar filament is a cylindrical crystal of a protein known as flagellin. Flagellin subunits travel from the cytoplasm through a 2 nm axial pore and polymerize at the filament’s distal end. They are supplied by a pump in the cell membrane powered by a proton-motive force. In a recent experiment, it was observed that growth proceeded at a rate of approximately one subunit every 2 s. Here, we asked whether transport of subunits through the pore at this rate could be effected by single-file diffusion, which we simulated by a random walk on a one-dimensional lattice. Assuming that the subunits are α-helical, the answer is yes, by a comfortable margin.en-USJournal Article2014-06-1810.1016/j.bpj.2013.05.030