Figure 2

Maximum Likelihood phylogenetic reconstruction of the NRT2 family. Taxonomic groups are colored as described in Figure 1. A) Phylogram of the NRT2 family including 81 plant sequences only. Chlorophyte sequences were used to root the tree. Bootstrap values of the ML analysis are given and corresponding bootstrap values (>75%) from a distance neighbor joining and a parsimony analysis are indicated as green and red stars, respectively (within groups, bootstrap values >75% are displayed as stars only for all three analyses). Subcellular localization predictions are indicated as colored boxes framing gene identifiers and transmembrane topology predictions are given as numbers to the right of the gene identifier. A classification system is indicated as group labels to the right (E = eudicot, M = monocot). B) Unrooted phylogeny of the NRT2 family including twelve non-plant sequences identified as best GenBank BLAST hits using representative members from each plant group. Bootstrap values are given for central branches only up to the branch defining a group. Approximate locations of functionally characterized members discussed in the text are indicated.For database accession numbers of the 93 protein sequences included, see Additional file 1.