Figure 1.

Semi-surface representation of the structure of the bacterial flagellar motor in a gram-negative bacterium with the LP ring in dark blue, MS ring in green, and stators represented as cartoon cylinders: MotA₅B₂ (PDBID: 6YKM) in blue-orange with five MotA (blue) subunits assembled around the MotB (orange) dimer on the left, and a representative example PomA₅B₂, in purple, on the right. The peptidoglycan binding domain of MotB/PomB (light grey) extends from the transmembrane units to the peptidoglycan domain of MotB/PomB. The Hook and Rod are represented in light brown, with the C Ring in dark brown. Arrows represent direction of ion travel. OM: Outer Membrane; PG: Peptidoglycan Layer; IM: Inner Membrane. Basal body/hook PDBID: 7CGO; stator: PDBID: 6YKM. Inset is an illustrative comparison of the bacterial flagellar motor in Gram-positive bacteria (left) and Gram-negative bacteria (right), highlighting the differences in the cell-wall composition and the Rings in the BFM.