Phylogenetic analysis of plant potassium channels and amino acid sequence alignment of four KAT potassium channel proteins.

<p>A, Phylogenetic tree derived from an amino acid sequence alignment of <i>Arabidopsis</i> and rice potassium channel proteins. The tree was generated using the Mega 5.0 program by maximum likelihood method. The tree is drawn to scale, with branch lengths measured in the number of substitutions per site. B, The amino acid sequences of three OsKATs from rice, AtKAT1 and 2 from <i>Arabidopsis</i> were aligned using the program CLUSTALX. Identical amino acids are shaded. The consensus TXGYGD motif in the K⁺-selective pore-forming loop region is indicated in the box drawn with bold line. The regions in the boxes drawn with solid lines are transmembrane domains (S1-S6).