Distance tree of training data and independent test data. Distance tree illustrating the relative similarities of the 54 sets of six selected informative residues from the training set and the corresponding residues in the 13 sequences that were used for independent testing of the prediction performance. The names of the training set channels have been removed for clarity. Each of the four subfamilies form well supported clades, and are labeled as Kv1, Kv2, Kv3, and Kv4. The branches and names of the wild type VKC channels from the independent test set are in red. Most test VKC sequences are clustered closely with one or more channels from the training data. Two VKCs from Hirudo medicinalis (LeechKv1) and Ciona intestinalis (CionaKv4), have long branch lengths.