TABLE 3.

Inactivation of IscR derepresses the isc operon^a

Strain	Relevant genotype	β-Galactosidase activity (Miller units)
DM10310	Wild type	70 ± 4
DM10300	apbC	70 ± 2
JE10432	iscR::Kan	390 ± 72
DM10474	apbC iscR6	270 ± 28
DM10476	apbC iscR7	430 ± 47
DM10480	apbC iscR8	350 ± 31
DM10482	apbC iscR9	340 ± 28
DM10484	apbC iscR10	290 ± 22

^aAll strains contained a plasmid that carried the isc reporter-lacZ fusion as described in the text. Strains were grown in LB-ampicillin medium to the mid-exponential phase of cell growth. β-Galactosidase assays were performed as described in Materials and Methods.