The SSL3–TLR2 binding interface reveals differences in species within the SSL3 binding region of TLR2. A The binding interface between SSL3 and murine TLR2 revealed 16 potential sites of interaction between SSL3 and TLR2. SSL3 is shown in orange and TLR2 is shown in green. Image adapted from Koymans et al.  (PDB ID code 5D3I). B Sequence alignment of the TLR2 region involved in SSL3 binding of nine different animal species. Conserved amino acids found in the binding interface are highlighted in gray, while the amino acids that differ between species are highlighted in green (conserved as compared to murine TLR2) or blue (different as compared to murine TLR2). C Homology models of human, equine, and bovine TLR2 derived from the structure of the murine TLR2–SSL3 complex (PDB ID code 5D3I). TLR2 is shown in green and the amino acids and regions that differ have been highlighted in blue.