Glucose transporter topology

Figure 8-23 Predicted topology of the human glucose transporter GLUT1. The 12 predicted helices are numbered and the single external N-linked oligosaccharide is marked CHO. The sequence RXGRR (marked) is found in many 12-helix transporters. Its occurrence in these two positions suggests that the transporters may have evolved by duplication of a 6-helix motif. However, the human glucose transporters otherwise show no sequence similarity to other 12-helix transporters. After Bell et al.398...

Glucose tolerance factor chromium in 888 Glucose transporters 415, 416 GLUT1, topology diagram 416 GLUT4, response to insulin 416 Glucosidase... 

Figure 2. Topology of facilitative glucose transporters in the membrane. The numbered open rectangles represent transmembrane domains, the gray rectangle represents the plasma membrane, and the NH2 and COOH termini are indicated. Curved black lines represent hydrophilic loops that connect transmembrane domains.

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