Figure 2.

Genomic organization of aromatic-pathway genes in cyanobacteria. Genes relevant to the common pathway segment, the tryptophan branch, the tyrosine branch, and the phenylalanine branch are color-coded, as indicated. A system for uniform genomic naming of Trp-pathway genes or domains has been used as previously implemented [23,57]. Fused catalytic domains are joined by solid black linkers. Gene positions along the entire chromosomes of Synechocystis sp. PCC 6803 and Anabaena sp. PCC 7120 are shown. The qualitative presence or absence of genes in Nostoc punctiforme, an unfinished genome, is also indicated. Detailed zoom-in schematics are shown for the gene organizations within the supraoperons of Anabaena and Nostoc, regions spanning 13,000-14,000 bp. In the latter regions, intergenic spacing is shown, with negative values indicating the extent of genic overlap.