Figure 2

An unrooted, maximum likelihood phylogenetic tree of all proteins. The analysis included all the proteins detailed in Additional file 1. The tree was generated by MEGA5[45], after alignment of the sequences, as detailed in the Methods. The bootstrap consensus tree inferred from 1000 replicates is presented. Branch lengths are represented by the solid (but not the dashed) lines. The percentage of replicate trees in which the associated proteins cluster together in the bootstrap test are indicated in Additional file 4, which presents the results of the same phylogenetic analysis shown here in the form of a rooted tree.