Extended Data Fig. 4: Overall structural features of the PfHT1 structure.
From: The molecular basis for sugar import in malaria parasites
a, PfHT1 crystallized as a dimer with four molecules in the asymmetric unit. The shared dimer interface was formed between the respective N-terminal domains (blue) that—although not extensive (522 Å buried surface area)—are consistent with the fact that a fraction of purified PfHT1 migrates as a dimer by size-exclusion chromatography (Extended Data Fig. 2a). Notably, the gating helix TM7b is not making any crystal contacts. b, Superposition of the outward-occluded GLUT3 (PDB 4ZWB) (grey) and the occluded PfHT1 structures. The r.m.s.d. is 1.4 Å for 446 pairs of Cα atoms (Methods). c, Cartoon representation of PfHT1 as viewed from the cytoplasm. Blue, NTD; magenta, CTD. ICHs are not shown for clarity. Interdomain salt-bridge-forming residues are shown as sticks, and labelled. d, Cartoon representation of TM7b of human GLUT1 (PDB 4PYP) (orange) and bovine GLUT5 (PDB 4YB9) (purple) in the inward-open conformation, and PfHT1 in the d-glucose-bound (yellow sticks) occluded conformation (magenta). e, Electron density map 2Fo − Fc (1.5σ) (blue mesh) for the PfHT1 structure (left) and the d-glucose residues in the sugar-binding pocket in cyan (right). The Fo – Fc (3.0σ) (green mesh) maps before addition of and refinement in the presence of d-glucose are also shown. Despite the high quality of the maps, we observed no electron density for ICH5 (location in human GLUT3 shown as a dashed ellipse).
