Figure 4

Structural comparison of the PIP₂ binding site of ECTV-PH and human profilin 1. (A) Surface diagrams of the ECTV-PH structural model and the human profilin 1 crystal structure using a blue background with the important PIP₂ binding residues coloured in green. The dark red residue represents the one residue (R-130 in ECTV-PH, R-135 in human profilin 1) that is identical between both structures; the orange residue represents the one functionally conserved residue (R-120 in ECTV-PH, K-125 in human profilin 1.) (B) Surface diagrams of ECTV-PH and human profilin 1 with residues coloured by amino acid property as follows: aromatic residues (F, Y, W) in purple; negatively charged residues (D, E) in red; positively charged residues (R, H, K) in dark blue; non-polar/aliphatic residues (G, I, L, M, V) in gold; and polar/uncharged residues (N, Q, P, S, T) in light blue. The arrows in panels A and B indicate the loop located between beta-strands 5 and 6 of human profilin 1 implicated in PIP₂ binding that is reduced in size in ECTV-PH.