Structures of SoPIP2;1 and GlpF. (a) Model of the spinach SoPIP2;1 water channel structure (Protein Data Bank (PDB) entry 1Z98), showing water molecules passing through the channel (red spheres). (b) Model of the E. coli GlpF glycerol channel (PDB 1LDI) showing water molecules passing through the channel (red spheres). In each structure, the amino-terminal half is in green and the carboxy-terminal half is in purple. (c, d) Cross-sectional views of SoPIP2;1 and GlpF, showing the narrowest opening of the pore with a water or glycerol molecule, respectively.
Bhattacharjee et al. Journal of Biology 2008 7:33 doi:10.1186/jbiol91