TABLE 3.
Fis protein | fis P II Kd (nM)a | hin distal Kd (nM)a | λ attR Kd (nM)a |
---|---|---|---|
WT | 1.0 ± 0.1 | 1.0 ± 0.2 | 4.1 ± 0.4 |
N73A | 47 ± 8 | 65 ± 7 | 91 ± 39 |
Q74A | 1.7 ± 2 | 3.8 ± 0.5 | 6 ± 1.1 |
T75A | 8 ± 1 | 6.3 ± 0.7 | 29 ± 13 |
R76A | 10 ± 1 | 6 ± 0.9 | 37 ± 10b |
N84A | 1.5 ± 0.2 | 1.9 ± 2.1 | 157 ± 15 |
R85Ac | >2,200d | >2,200d | >2,200d |
T87A | 1,100 ± 316 | >2,200d | 1,300 ± 545 |
R89A | 232 ± 59 | >2,200d | 466 ± 271 |
K90Ac | >2,200d | >2,200d | >2,200d |
K91A | 24 ± 18 | >2,200d | >2,200d |
K93A | 20 ± 2 | 9 ± 4 | 46 ± 15 |
K94A | 37 ± 8 | 6.4 ± 1.4 | 18 ± 11 |
N98A | 1.0 ± 0.1 | 1.2 ± 0.6 | 2.7 ± 0.7 |
Gel mobility shift assays were performed as described in the legend to Fig. 1 with 42-bp DNA fragments carrying the fis P II, hin distal, or λ attR sequences. The percentage of bound DNA at equilibrium was plotted against the Fis concentration used, as shown in Fig. 1A, and the concentrations required to achieve 50% binding were considered approximate Kd values for the binding reactions. The data are averages ± standard deviations for three experiments unless indicated otherwise.
The data are the average ± standard deviation for two experiments.
No discrete bound complexes were observed with this mutant.
The maximum Fis concentration used in the assays was 2.2 μM, at which less than 50% binding was observed.