Figure 1

Influence of Zur and zinc availability in the expression of Zur-repressed genes. Transcriptional fusions of znuK, znuL, znuM, zrpWX and znuGHI promoter regions to the lacZ reporter gene were introduced into NA1000, MM69, MM69 (pUJ) and MM69 (pUJ-zur) strains, and grown under different regimens of zinc availability. Expression was determined by β-galactosidase activity assays. White bars indicate M2 medium supplied with 500 μM ZnCl₂, light grey bars indicate M2 medium supplied with 500 μM EDTA and dark grey bars indicate M2 medium supplied with 500 μM ZnCl₂ and 500 μM EDTA. In the complementation analysis, MM69 strain harboring plasmid pUJ142 without insert (−) or carrying the zur gene (+) was used. The results shown are the average of at least three experiments. Error bars indicate standard deviations.