Genetic organization and the predicted primary structure of PnxIIIA in P. pneumotropica ATCC 35149. (A) Schematic representation of the pnxIII operon genetic map and the functions of each gene. Circles represent potential transcriptional termination loops. Predicted functions determined by the protein database are indicated below the gray boxes. (B) Schematic representation of probable domains that were identified by comparing with the HMM database. The numbers represent the regions containing a large repeat sequence. Arrowheads below the number box represent the position of sequence alignment in Additional file 1.