Figure 7
Hypothesis of HKT polymer model. Two highly conserved cysteine (Cys) residues form disulfide bonds to help HKTs to assemble a dimer or tetramer and stabilize the structures. Positive arginine (Arg) and lysine (Lys) residues form a cation barrier to stop cation across. Two/four serine (Ser) or glycine (Gly) residues form a cation trap for plant HKTs specifically selecting cation. a) dimer model and b) tetramer model.