AA interacts preferably with residues located at the extracellular side of TM1. AA occupancy at residues in the upper region of the TM1 and TM2 helices calculated as averages over three chains in three repeats of 30 µs each. Residues on the x-axis are labeled with the hASIC3 residue on the left and the hASIC1a residue on the right, in the form hASIC3/hASIC1a. (A) Occupancies of AA at TM1 residues for hASIC3 in cyan and hASIC1a in orange. Black lines show standard deviations, bars show averages, and points show individual samples. (B) Occupancies of AA at TM2 residues (colors like A). (C) The same occupancy information as in A and B presented as a heatmap superimposed on models of hASIC1a and hASIC3.