Histidine synthesis in T. ferrooxidans. Legend as in Fig. 2. Additional microorganism data bases used were BA, Buchnera aphidicola; BP, Bordetella pertussis; CL, Cervus elaphus;; KL, Kluyveromyces lactis; LL, Lactococcus lactis; MB, Mycobacterium bovis; MI, Mycobacterium smegmatis; MN, Streptococcus mutans; SA, Staphylococcus aureus; SX, Staphylococcus xylosus; SY, Synechococcus sp.; TY, Salmonella typhimurium; and XA, Xanthomonas campestris.