Alignment of the helix A-B linker in Kv7.2-7.4 channels implicated in PIP₂ interactions by this study. Shown is the alignment of the 57-residue core of the linker between helices A and B. The Kv7.3/7.4_C-2 chimera is shown schematically on the left. Conserved basic residues tested in this study by mutagenesis of Kv7.2 or Kv7.3 are indicated in red; nonconserved residues tested by swapping them between Kv7.2 and 7.3 are indicated in blue. The large and small boxes enclose a cluster of positively charged residues and a critical conserved basic residue, respectively.