Schematic representation of the S. erythraea E3 genome. The outer scale is numbered in megabases from the origin of replication (ori) and the first circle indicates the core (red) and noncore (blue) regions, and the boundaries between them are mark by gradient colors. Circles 2, 3 and 4 (from the outside in), whole genome alignment (by Mummer) between S. erythraea and M. tuberculosis, N. farcinica, S. coelicolor, respectively (conservation of sequence regions are marked by gradient colors: blue, yellow, red. Most conserved regions are in red.). Circles 5 and 6, all genes (forward and reverse strand, respectively) colored corresponding to the COG functional assignment. Circle 7, tRNAs (red) and rRNAs (skyblue). Circle 8, GC content; circle 9, GC skew ((G – C/G + C), plum indicates values >1, lightblue values <1).