Fig. 3. Structural comparison of GLUT3-SA47 and GLUT3-glucose complexes.

a The structure of GLUT3-SA47 exhibits a similar outward-open state as that of maltose-bound GLUT3. The radii of extracellular substrate access tunnel in the indicated GLUT3 structures were calculated in HOLE³⁴. The glucose-binding site in GLUT3-glucose complex is indicated by the gray shade. b Partial overlap between SA47 and glucose in GLUT3. TM11 is omitted for a clear view of ligands. SA47 and glucose are shown as black ball-and-sticks and green sticks, respectively. c Local conformational shifts between GLUT3-SA47 and GLUT3-glucose. The arrows indicate the TM movements that widen the path to the central pocket. TM11 is omitted for a clear view of the movement of TM7b, which is colored in GLUT3-SA47. d Structural shift of TM7b residues upon SA47 binding. The corresponding TM7b residues in GLUT3-SA47 and GLUT3-glucose are colored orange and gray, respectively.