Circular representation of the A. ferrooxidans ATCC 23270 genome sequence. The two outer circles represent predicted protein encoding-genes on the forward and reverse strands, respectively. Functional categories are indicated by color, as follows: energy metabolism (green), DNA metabolism (red), protein synthesis (magenta), transcription (yellow), amino acid metabolism (orange), central intermediary metabolism (dark blue), cellular processes (light blue), nucleotide metabolism (turquoise), hypothetical and conserved hypothetical proteins (grey), mobile and extra-chromosomal elements (black), and general functions (brown). The third and fourth circles (forward and reverse strands) indicate major transposases and mobile elements (orange), plasmid-related genes (red), and phage elements (blue). The fifth and sixth circles (forward and reverse strands) indicate tRNA genes (gray). The seventh and eighth circles (forward and reverse strands) show genes predicted to be involved in sulfur (purple), iron (red), and hydrogen (orange) oxidation. The ninth and tenth circles show genomic GC bias and GC skew, respectively.