FIG 2.

Gene organization of the ST- and BD-12-biosynthetic gene clusters. The ST-biosynthetic gene cluster (accession no. AB684619) from S. rochei NBRC 12908 (top) and the BD-12-biosynthetic gene cluster (accession no. LC122485) from S. luteocolor NBRC 13826 (bottom) are shown. The dark-gray-shaded genes are the genes responsible for the peptide bond formation between streptothrisamine and the amino acid residues. The light-gray-shaded genes are the genes responsible for streptothrisamine biosynthesis. The lines connect homologuous genes in the two biosynthetic gene clusters.