Table 3.
CreWT and CreQQ HJ Formation Kinetic Parameters
| reaction | HJ extenta, f | A | k1 (× 103 s−1) | k2 (× 103 s−1) | t1/2 (s)b |
|---|---|---|---|---|---|
| CreWT-LoxP | 11 ± 1 | 0.63 ± 0.03 | 5.3 ± 0.2 | 49 ± 13 | 53 |
| LoxTA | 12 ± 3 | 0.41 ± 0.17 | 13 ± 3 | 45 ± 6 | 29 |
| LoxAT | 8 ± 1 | 0.47 ± 0.01 | 6.6 ± 0.2 | 32 ± 11 | 41 |
| LoxGCc | 1.2 | 0.74 | 5.8 | 71 | 88 |
| CreQQ-LoxP | 11 ± 1 | 0.50 ± 0.04 | 7.9 ± 1.2 | 89 ± 1 | 21 |
| LoxTA | 24 ± 3 | 0.47 ± 0.05 | 8.5 ± 0.9 | 90 ± 4 | 19 |
| LoxAT | 15 ± 1 | 0.30 ± 0.01 | 3.2 ± 0.1 | 96 ± 1 | 14 |
| LoxGC | 21 ± 2 | 0.34 ± 0.13 | 8.8 ± 1.8 | 68 ± 10 | 17 |
a
The fit value of "f" describes the maximal amount substrate reacted to HJ complexes only; HJ extent + products extent (Table 4) ≅ extent (Table 2).
b
Values for t1/2 are calculated based on the averaged curve fits for each reaction (see Figure 5).
c
Because of low substrate turnover, the parameters reported are from the fit of the averaged data points from four replicate reactions. The data were fit to the sequential a → b → c kinetic model described in Experimental Procedures, for comparison with CreWT/LoxGC product formation.