Comparison of the pyoverdine loci of P. aeruginosa PAO1 and P. syringae 1448a. A. The core PAO1 pyoverdine genes fall into two closely linked clusters, 11 kb apart. In contrast, the core P. syringae 1448a genes form a single contiguous cluster. Genes are color coded according to their function, as indicated in the key; and orthologous genes in each organism have been assigned the same number, corresponding to the annotations in Table 1. The green highlighted region details the modular structure of the P. syringae 1448a pyoverdine NRPS genes (C = condensation domain, A = Adenylation domain, T = Thiolation domain, E = Epimerization domain, TE = Thioesterase domain). A-domains are color coded to correspond with the amino acid residue that each incorporates into the P. syringae 1448a pyoverdine molecule (as pictured in B).