Figure 2.
Phylogenetic tree of 37 known and predicted proton channels. Branch length indicates the evolutionary distance between sequences. This maximum likelihood phylogenetic tree was constructed from a multiple sequence alignment of the voltage sensing domain (VSD) portion of 37 HV1s using 100 bootstraps. The eight HV1 genes that have been confirmed by heterologous expression and electrophysiological recording are starred. Bootstrap values >60 are shown; these numbers indicate the probability that the branch is genuine. [From Smith et al. (462).]