Ubiquinone biosynthesis pathway of “ Ca . S. mobilis”. This pathway is compared with the ubiquinone biosynthesis pathways found in 15 members of the Comamonadaceae, including the 8 listed in the Figure 2 legend as well as 3 additional Acidovorax spp., 2 additional Comamonas spp., one additional Polaromonas sp. and one additional Variovorax sp. The ubiC gene was identified in only one of the 15 genomes, possibly because of its extremely low sequence similarity and conservation across species. The ubiH/coq6 and ubiF/coq7 genes are highly conserved and were identified in each of the 15 reference genomes, but these genes were not found in “Ca. S. mobilis”.