Bacterial Flagella: Twist and Stick, or Dodge across the Kingdoms
Figure 2
Cross-kingdom immune recognition of flagellin structures.
Top: backbone of the key residues of flagellin recognized by plant (left) and animal (right) innate immune receptors are highlighted in red. FliC from S. enterica is presented as a “model” flagellin, with reports for recognition by both TLR5 and FLS2 receptors. These residues are superimposed on the solved flagellin structure (PDB# 1UCU) in UCSF Chimera [113]. Surfaces and backbone are coloured according to previously assigned structural domains as indicated below each monomer [57]. Bottom: recognition of flagella filaments by plant (left) and animal (right) innate immune receptors does not occur as key residues (surfaces highlighted in red) are hidden within the filament structure. However, immune recognition still occurs in animals via antibody recognition of the D3 domain.