Fig. 2.

Structure of the four histidine operons in C. glutamicum. Canonical histidine biosynthesis genes are depicted in dark blue. Genes shown in light blue exhibit high sequence similarity to hisN. Genes shown in white have no apparent function in histidine biosynthesis. Arrows indicate the positions of putative primary and internal promoters. Presence of a SD sequence is marked with an asterisk. The ruler indicates the absolute position within the genome (based on the genome version by Kalinowski et al., 2003 RefSeq NC_006958.1).