TABLE 4.
Effects of λ attR flanking sequences on binding of wild-type and mutant Fis
| Fis protein | λ attRpdKd (nM)a | λ attRnatKd (nM)a |
|---|---|---|
| WT | 4.1 ± 0.4 | 0.33 ± 0.05 |
| N73A | 91 ± 39 | 239 ± 29 |
| Q74A | 6 ± 1 | 1.2 ± 0.0 |
| T75A | 29 ± 13 | 54 ± 7 |
| R76A | 37 ± 10b | 30 ± 1 |
| N84A | 157 ± 15 | 169 ± 41 |
| R85A | >2,200 | >2,200 |
| T87A | 1,300 ± 545 | 1,420 ± 30 |
| R89A | 466 ± 271 | 12 ± 0.1 |
| K90A | >2,200 | >2,200 |
| K91A | >2,200 | 416 ± 20 |
| K93A | 46 ± 15 | 100 ± 16 |
| K94A | 18 ± 11 | 16 ± 2 |
| N98A | 2.7 ± 0.7 | 0.7 ± 0.3 |
a
Gel mobility shift assays were performed as described in the legend to Fig. 1 with a 42-bp DNA fragment carrying λ attRpd, the λ attR 15-bp core sequence flanked by plasmid-derived sequences, as shown in Fig. 1B, or with a 53-bp DNA fragment carrying λ attRnat, the λ attR sequence flanked on each side by 5-bp natural sequences. The apparent Kd values are averages ± standard deviations for three binding assays, unless indicated otherwise.
b
The data are the average ± standard deviation for two experiments.