Table 4. β-Galactosidase expression by E. coli strains carrying wild-type and mutant forms of DtxR with various amino acids at position 175 grown under iron-replete and iron-limiting conditions.

	β-Galactosidase, % of control
Amino acid at position 175	LB/Amp/Kan	LB/Amp/Kan + 300 μM DP
E*	0.24 ± 0.12	48.4 ± 2.83
D	0.41 ± 0.23	48.7 ± 2.92
K	0.20 ± 0.10	8.71 ± 0.25
R	0.16 ± 0.03	8.93 ± 1.08
Q	0.14 ± 0.01	21.2 ± 0.31
A	0.12 ± 0.05	24.6 ± 1.61

^*Wild type