TABLE 2.

Determination of apparent dissociation constants of wild-type and TtgV mutants for the operators at the ttgG and ttgD promotersa

TtgV protein variantKD (nM) for ttgD operatorKD (nM) for ttgG operator
Wild type10 ± 119 ± 1
R47A>750>750
V50A49 ± 11>750
Q51A8 ± 119 ± 1
I53A42 ± 3ND
I54A27 ± 2>750
E60A26 ± 1>750
F61A25 ± 2>750
  • a Data were obtained from densitometric analyses of EMSAs in the presence of concentrations of 1, 5, 10, 20, 30, 40, 50, 100, 500, and 750 nM. Results shown are the means for at least four independent assays done in duplicate. The DNA probe was 1 nM of a 295-bp fragment comprising the entire ttgG or ttgD promoter region. ND, not determined.