Fig. 2: Sugar-binding pocket in BmGr9.
From: The molecular basis of sugar detection by an insect taste receptor
a,b, Position of β-d-fructopyranose (grey, carbons; red, oxygens) within a subunit of BmGr9 (blue) viewed from the top (a) and side (b). c,d, Close-up views showing interactions between BmGr9 and d-fructose (with carbons numbered). Polar interactions are drawn as dashed lines. In c, hydrogens on d-fructose (white) are shown to highlight hydrophobic interactions with Trp354 and Phe333 (indicated by vertical dashes). e, Effect of substitutions within the sugar-binding pocket on the activity of BmGr9. Bars are mean ± s.e.m. with independent samples shown as open circles. Only wild-type BmGr9 and Q351A have significantly different activity from that of GCaMP alone (indicated by grey bars). Statistical significance was determined using one-way analysis of variance (ANOVA) followed by Dunnett’s multiple comparison tests (***P < 0.0001, *P = 0.035). f, Dose response of select mutants from e. Data points are mean ± s.e.m. from n = 6 (Q351A and T330A) or 8 (wild-type BmGr9) independent samples measured from the same plates.
