Extended Data Fig. 5: Amphipathic nature of helical regions at the plasma membrane leaflets.
From: Structure and sucrose binding mechanism of the plant SUC1 sucrose transporter
a, Side views of the SUC1 structure with molecular lipophilicity potential (MLP) shown as molecular surface and coloured from dark cyan (most hydrophilic) to dark goldenrod (most lipophilic). Insets highlight helical regions at the plasma membrane leaflets. Membrane boundaries (outer leaflet; blue, inner leaflet; red) were calculated using the PPM web server93. b, Amphipathic intracellular helical region (IHR) shown as cartoon with labelled residues as sticks (left) coloured according to lipophilicity as in panel A and Edmundson wheel projection diagram of the residues of helical region with hydrophobic residues facing the inner leaflet of the plasma membrane and polar residues facing the cytoplasm (right). c, Amphipathic extracellular helical region (EHR) shown as cartoon and labeled residues as sticks (left) colored according to lipophilicity as in panel A and Edmundson wheel projection diagram of the residues of helical region with hydrophobic residues facing the outer leaflet of the plasma membrane and polar residues facing the apoplast. d, Oocyte uptake assay for SUC1 mutants targeting the IHR. Uptake activities are normalized to that of the wild type. Control is water injected oocytes. Bars are mean ± s.d. Data points are individual experiments (n = 6 (I272S/F273S,E271A,F276S), n = 7 (L268S/F269S), n = 11 (L268S/F269S/I272S/F273S/F276S), n = 16(WT)). P values for differences between wild type and variants was from a one-way ANOVA analysis followed by Dunnett’s multiple comparisons test (p = 0.9145 (L268S/F269S/I272S/F273S/F278S), p = 0.2915 (I272S/F273S), p = 0.8544 (F276S), p = 0.6264 (E271A)). e, Oocyte uptake assay for SUC1 mutants targeting the EHR. Uptake activities are normalized to that of the wild type. Control is water injected oocytes. Bars are mean ± s.d. Data points are individual experiments (n = 3 (L204S/M207S, F208S), n = 6 (L204A/M207A/F208A), n = 7 (C216A), n = 16 (WT)). P values for differences between wild type and variants was from a one-way ANOVA analysis followed by Dunnett’s multiple comparisons test (p = 0.4290 (L204A/ M207A/F208A)).
