Phylogenetic tree based on 16S rRNA gene sequences of acholeplasmas (orange) and phytoplasmas (green). The tree was calculated by employing the maximum likelihood algorithm and bootstrap calculation for 1,000 replicates (only values of at least 70% are shown). The bar indicates 0.05 substitutions per nucleotide. The accession numbers are given in parentheses. Mycoplasma genitalium strain G37 is set as an out-group. Species with complete chromosomes available are shown in bold. Roman numerals are given according to acholeplasma clades . The coloured boxes indicate that gene encoding F1F0 Na+ ATP synthase (light blue), V1VO Na+ ATP synthase (yellow), V1VO H+ ATP synthase (dark blue), GroEL (red) or SecB (violet) are present (limited to complete genome sequences).