Extended Data Fig. 8: Sodium-binding sites and SMCT1’s substrate binding site.
From: Structure and mechanism of the SGLT family of glucose transporters
a, Structural overlay of SGLT1conHA (orange), SMCT1 (cyan), and SiaT (gray, PDB: 5NV9). The helices involved in sodium binding are shown as ribbons. The shift of TM helices from SiaT to SGLT1conHA or SMCT1-butyrate is depicted by red arrows. b, Sodium-binding sites compared between SGLT1conHA (yellow) or SMCT1 (yellow) and SiaT (gray). Residues in Na2 or Na3 sites are shown as sticks. c, Uptake activities of SGLT1 with mutations in the Na3-binding site. Uptake activities are normalized to WT (mean ± SEM; n=4 biological replicates). d, SMCT1-butyrate interaction shown as Ligplot+ diagram (yellow dashed lines, hydrogen bonds; spokes, hydrophobic interactions). e, Pyruvate uptake activities of SMCT1 mutants compared to WT (mean ± SEM; n=3 biological replicates).
