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Figure 3 | BMC Microbiology

Figure 3

From: Cysteine coordination of Pb(II) is involved in the PbrR-dependent activation of the lead-resistance promoter, PpbrA, from Cupriavidus metallidurans CH34

Figure 3

(A) β-galactosidase assay measurement of the activation of P pbrA , containing a 1 nt deletion in the 19 bp promoter spacer, to increasing levels of Pb(II) in C. metallidurans AE104 carrying pMUPbrR pbrA -1. Micromolar Pb(II) concentrations are indicated by the suffix to Pb on the abscissa. Pb0 contains no added Pb(II), Pb200 contains 200 μM Pb(II) . The sequence of wild-type PpbrA and the −1 mutant PpbrA are shown below the graph. The −35 and −10 sequences are marked in BOLD. Arrows show dyad symmetrical DNA sequences within the promoters. (B) β-galactosidase assay measurement of the activation of −10 sequence mutant PpbrA clones in pMU2385 in response to no added Pb(II) or 100 μM Pb(II). WT denotes wild-type −10 sequence (TTAAAT), CON denotes the E. coli consensus promoter −10 sequence (TATAAT) and MER the Tn501 PmerT promoter −10 sequence (TAAGGT). The sequences of the wild-type (PpbrA wt), consensus (PpbrA con), and PmerT-like promoters (PpbrA mer) are shown below the graph. The −35 and −10 sequences are marked in BOLD. Arrows show dyad symmetrical DNA sequences within the promoters, and altered bases are marked in Gray.

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BMC Microbiology

ISSN: 1471-2180

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