Figure 15.1 : Structure of Flagellum

Flagellum (Figure 15.1) is a lash-like cell surface appendages and it consists of protein flagellin. It generally divided into 3 portions and they are basal body, hook and filament. Basal body areimplanted in cell wall. Basal body of the flagellum has M (motor) ring, S(stator) ring and C ring. M and s ring together bind with peptidoglycan layer of the bacteria whereas c ring present in the cytoplasmic region. Basal body is connected with the filament by hook. Flagellum can rotate either clockwise or anticlockwise. Further basal body has around 40 proteins including ‘mot’ proteins and ‘fli’ proteins which are essential in the active movement through proton pumping mechanism. Ex. for flageller bacteria Vibrio, Spirillum, Salmonella,Klebsiella, etc.