Distribution of co-evolving amino acids residues mapped onto the surface of TLR2 family protein structures. The protein structures are from Jin et al. (2007) and Kang et al. (2009). Co-evolving amino acids are shown as either network diagrams (displayed using Cytoscape) or mapped onto tertiary structures of protein domains (using PyMOL) for A: human TLR1/TLR2 and B: mouse TLR6/TLR2 complexes. In the network diagrams the TLR1/TLR6 and TLR2 amino acids are depicted by ellipse and rectangle shapes, respectively. Cyan, pale green and pink amino acid residues represent the ligand binding domain, α helices near the ligand binding domain and the extracellular domain, respectively. The color of lines in A(i) and B(i) represents the correlation coefficients of co-evolving amino acids. In the tertiary structures the peptide fragments from TLR1/TLR6 and TLR2 are in pale green and yellow, respectively. Amino acids joined by the same color of the broken lines are clustered to the one evolutionary group.