ß-Galactosidase activity Promoter Mutated site minus NO 3 plus NO 3 Fold induction ogt100 93 + 1 439 + 12 4.7 ogt102 NarL I 92 + 5 107 + 6 1.2 ogt104 NarL II 56 + 2 87 + 3 1.6 the yeaR promoter is repressed by the binding of NsrR to a target that overlaps the 10 hexamer element  [ 12,31,32 ] .