Unrooted maximum-likelihood tree based on concatenated ribosomal proteins for 120 eubacterial species. The following 37 sequences were concatenated: RplABCDFIJKLMNOPQRSTUVW, RpmA, RpsBCDEFGHIKLMOQRST, filter by a 40% positional conservation filter resulting in 5182 amino acid positions. The tree was calculated from this alignment using the ProML program of the PLYLIPackage (settings: best tree search mode; JTT model of amino acid substitution; one category of sites with a constant evolutionary rate; no weights; rough-type of analysis with global rearrangements). Bootstrapping was carried out with 100 replicates. Numbers in parentheses refer to the numbers of species that make up the respective branch.