Fig. 2
From: Evolution of transcriptional regulation of histidine metabolism in Gram-positive bacteria
Genomic context of the reconstructed HisR and RNA regulons for histidine metabolism genes in Firmicutes and other bacterial phyla. Histidine biosynthesis and transport genes are shown by white and gray arrows, respectively. HisR repressor genes are in black. Candidate HisR-binding sites are shown by black circles. T-boxes and RNA attenuators are shown by black squares and rhombuses with ‘T’ and ‘A’ letters inside. Content of the reconstructed HisR regulons in other species and candidate HisR binding sites are listed in Additional files 3 and 4