Fig. 12

AQP8 models are compatible with existence of a water filled side pore beneath loop C. a Top view of loop C in aligned AQP8 models and AtTIP2;1 with amino acid residues shown as sticks and oxygens of waters in the side pore of AtTIP2;1 represented by dotted spheres. Although the monomeric models were generated without waters, there is no obvious clash with the four water molecules in the side pore. b Side view of the same region. The water molecule connecting the arginine at HE^P to a carbonyl oxygen in loop C can be accommodated in all models except HsAQP8. In human AQP8 this residue (A137) sits deeper and overlaps with the oxygen of the water from AtTIP2;1. Thereby it blocks a potential connection of the side pore to the main pore in this model. AtTIP2;1 – green, HsAQP8 – slate blue, BtAQP8 – cyan, RnAQP8 – orange, FpAQP8 – magenta, CpAQP8 – greenblue, XtAQP8 – yellow, SsAQP8b – salmon