Abstract
Type IV Pili (T4P) are retractable extracellular filaments of bacteria that allow twitching motility over surfaces. In the phytopathogen Xanthomonas citri pv. citri, T4P were also associated with biofilm formation and adhesion processes. In this organism, the secretin complex that forms the outer membrane channel for the passage of these filaments is being studied by electron cryomicrosco…