Figure 1
From: Toll-like receptors: a family of pattern-recognition receptors in mammals
Structural features of human members of the TLR protein family and the archetypal Drosophila Toll protein. Toll and its relatives are characterized by an amino-terminal extracellular leucine-rich repeat (LRR) domain, which is probably involved in ligand binding, and an intracellular Toll/interleukin-1 receptor (TIR) domain required for signal transduction. Known ligands of different TLRs and chromosomal locations of the human TLR genes are indicated. Red arrows indicate a possible dimerization between TLR1, TLR2 and TLR6. TLR9 is normally expressed intracellularly. Abbreviations: MALP-2, macrophage-activating lipopeptide-2; LAM, lipoarabinomannan; details of other ligands mentioned in the figure are discussed in the text.