Extended Data Fig. 9: Representative lipid-like densities in the Ostα/βapo structure.
From: Structures of Ostα/β reveal a unique fold and bile acid transport mechanism
a Representative non-protein densities surrounding the Ostα/βapo structure (contour = 0.21). Putative cholesterols (excluding those at the substrate binding sites) shown in transparent gray, phospholipid-like densities in transparent purple. b Enlarged view of density resembling lysophosphatidylglycerol (LPG). c Enlarged view of density resembling PE. d Lipid-Ostα/β interaction interface 1 (IF1) with surrounding residues with extended hydrophobic side chains. e-g, Cholesterol-Ostα/β interaction interface 2-5 (IF2-5), with surrounding residues with extended hydrophobic side chains. h, [³H]-TCA uptake activity of IF mutants compared to WT Ostα/β. Data are mean ± s.e.m. (n = 6 biological replicates per group, ***P = 0.0001; ****P < 0.0001. i, FASC analysis of IFs mutants showing differential effects on Ostα cell surface expression. Data are mean ± s.e.m. (n = 3 biological replicates per group, ****P < 0.0001, ns = not significant P > 0.05, **P < 0.01. The exact P-values for the respective IF-mutants 1-5: 0.3014, 0.1436, 0.0067, 0.6246, >0.999). j, Quantification of plasma membrane (green) and total (gray) Ostα expression levels in WT and IF-mutants backgrounds, normalized to WT Ostα/β membrane expression. Data are mean ± s.e.m. (n = 3 biological replicates per group). Unpaired t-tests were used for statistical comparisons; “nd” indicates no significant difference. The exact P values were: >0.9999, 0.0194, 0.7840, 0.6885, 0.0233, and 0.4872. h, i, Data analyzed by one-way ANOVA with Fisher’s LSD test. h-j, Results are representative of three independent experiments.
