Genomic atlas of S. amnii Sn35. Coordinates are indicated starting from the predicted origin of replication at base 1. Circles represent the following (from the outer circle inward): 1) Coding regions are marked on the first two rings: orange color if encoded on the positive strand and teal color if encoded on the negative strand. 2) location of the tRNA. 3) GC content using a 10-kbp sliding window, green, positive GC skew; gray, negative GC skew. The innermost graph shows the GC skew, with sharp changes in skew occurring at the putative origin and terminus of replication. The atlas was constructed using DNAPlotter .