Sequence logos for key motifs in homologues of VcINDY, MtrF, and YdaH. The conservation of motifs for VcINDY (A), MtrF (B), and YdaH (C) was evaluated separately over a set of close homologues of each protein (≥90% identity). The motifs for YdaH are identical to that of MtrF because the set of homologues contain >90% of the same sequences. Multiple sequence alignments of the homologue sequences were built in each case, and logos were created with WebLogo (version 3.4; Crooks et al., 2004). The secondary structure assignments are indicated by blue (helix) and gray (loop) rectangles. Yellow triangles indicate the residues involved in sodium binding according to the structural data.