The DNA sequence of five contiguous open reading frames encoding enzymes for phenazine biosynthesis in the biological control bacterium. Pseudomonas aureofaciens 30-84 was determined. These open reading frames were named phzF, phzA, phzB, phzC and phzD. Protein PhzF is similar to 3-deoxy-D-arabino-heptulosonate-7-phosphate synthases of solanaceous plants. PhzA is similar to 2,3-dihydro-2,3-dihydroxybenzoate synthase (EntB) of Escherichia coli. PhzB shares similarity with both subunits of anthranilate synthase and the phzB open reading frame complemented an E. coli trpE mutant deficient in anthranilate synthase activity. Although phzC shares little similarity to known genes, its product is responsible for the conversion of phenazine-I-carboxylic acid to 2-hydroxy-phenazine-I-carboxylic acid. PhzD is similar to pyridoxamine phosphate oxidases. These results indicate that phenazine biosynthesis in P. aureofaciens shares similarities with the shikimic acid, enterochelin, and tryptophan biosynthetic pathways.