Extended Data Fig. 4: Map densities of agonists and transmembrane α-helices.
From: Irritant-evoked activation and calcium modulation of the TRPA1 receptor
a, Strong density is observed for iodoacetamide bound to C621. Weaker density is observed next to C665, which indicate that some of the channels may be modified by agonist at this site. Map threshold: σ = 4. b, Clear density for BIA is observed bound to C621. No additional density is observed next to C665 in this case. Map threshold: σ = 6. c, Segmented map densities and atomic models for TRPA1 + BIA (LMNG). Scale bars, 3 Å. d, Map density of the A-loop in different states: undefined (TRPA1 + A-96, PMAL-C8), down (TRPA1 agonist-free, LMNG), and up (TRPA1 + BIA, LMNG). Densities are shown at two different thresholds (σ = 4 and 6). Scale bars, 5 Å.
