Figure 5.

Orthogonal views for the AQP1 channel. (a) The AQP1 tetramer sliced through the middle revealing the curved water-selective pathway in the two adjacent monomers and the region around the 4-fold axis as viewed parallel to the bilayer. The top is the extracellular side. The ≈25° bend of the pore as it traverses the bilayer is indicated by arrows. The color scheme of the residues is the same as in Fig. 2c. (b) A perspective view along the monomeric channel seen from the extracellular side; some of the residues lining the channel (including C189) are marked. The surface rendering of the atomic model was carried out by using the software msms (49) and a probe of radius 1.4Å.