Fig. 11From: A structural preview of aquaporin 8 via homology modeling of seven vertebrate isoformsAlternative cysteine rotamers at the selectivity filter of salmon AQP8. Cysteine 53 is modelled in two alternative conformations. The rotamer colored in green is turned towards arginine 213 at HEP with a distance of 3.3Â Ã…. If not oriented towards arginine 213, cysteine 53 can hydrogen bond to a serine (S128) in helix 3. Hydrogen bonds are depicted as dashes, and the pore is contoured by a dotted surface. The histidine at H2P (H72) stabilizes the position of arginine 213 by hydrogen bonding to the secondary ketimineBack to article page