Taxonomic groups most frequently found in association with proteins from genus Acidithiobacillus. The 34 most-frequently observed sister taxa (see Methods for details), covering a total of 504 trees, are shown in decreasing order of co-occurrence. An additional 795 trees in which Acidithiobacillus has multiple partners are not summarized, nor are 333 trees covering 179 other partner genera. Blue = Gamma-proteobacteria, red = Beta-proteobacteria, green = Alpha-proteobacteria, yellow = Delta-proteobacteria, orange = unclassified Proteobacteria (Magnetococcus), gray = other phyla. Alternating light and dark shades of the same color are used when two or more members of the same group are adjacent to one another in the chart.