ABSTRACT
Introduction..............................................................................................................49 Chemotaxis Regulated by Direction of Flagellar Rotation ....................................51 Various Flagellar Systems .......................................................................................53 Flagellar Genes ........................................................................................................53 Flagellar Formation .................................................................................................54 Flagellar-Specific Transport Apparatus ...................................................................55 Basal Body Proteins ................................................................................................57 Switch Complex.......................................................................................................58 Mot Proteins ............................................................................................................58 Ion Specificity of Proton and Sodium Type Motors...............................................60 References................................................................................................................62
A flagellum (plural is flagella) is an organelle that bacteria require for movement. A flagellum has a filamentous and spiral structure whose diameter is about 20 nm. Its length is several times longer than the length of the cell body (Figure 4.1a). This filament is rotated as a screw and generates a propulsive force. It has a tubular structure composed of single protein subunits known as flagellins. The flagellin molecules are piled in a spiral manner (Figure 4.1b). A flagellar filament is too thin to observe with an ordinary optical microscope; it can be seen with a dark-field microscope using a very strong light source.
