Figure 3: Molecular interactions at the interface.
From: Structure of the Acid-sensing ion channel 1 in complex with the gating modifier Psalmotoxin 1
(a) Ribbon representation of PcTx1 (green) and two of the three ASIC1 subunits (yellow and blue) viewed along helix 5 of the thumb at the surface of the extracellular domain. Side chains of residues with an intermolecular distance of ≤5 Å are shown detailing the interaction of the hydrophobic patch of PcTx1 with helix 5 of ASIC1. (b) View from the bottom of the acidic pocket outwards to the extracellular space. The view describes the charge–charge interactions between arginines of the basic cluster and the proton-sensing glutamates and aspartates of the ASIC1 palm, thumb and ball. The ASIC1 residues observed to interact with PcTx1 belong to the construction domains 3, 4 and 5 required for PcTx1 binding in ASIC1 chimeras22.
