Single-site statistics of the TRP- and Kv-sensor domain. (A) Aligned sequence logos for the TRP and the Kv channel superfamily in the sensor domain (S1–S4). Rat TRPV1 numbering is used for the TRP logo, and Shaker numbering is used for the Kv logo. Positions marked with an asterisk have Hrel(X(i)||Qref) > 1.25, where X is the TRP or Kv MSA position i. These high relative entropy positions are mapped onto the TRP (B)- and Kv (C)-sensor domains as molecular surfaces. Helices are colored as follows: red, S1; yellow, S2; green, S3; blue, S4. (D and E) Average polarity in the TRP (D)- and Kv (E)-sensor domains. Average polarity is calculated as the expected value of a position’s amino acid frequencies (normalized to remove gaps) and a biological hydrophobicity scale. Positions with an average polarity >1.0 kcal/mol (slightly more polar than serine) are shown as a blue surface.
