| G-T, no nucleotide, 10 min |
32±4 |
22±5 |
46±5 |
| G-T, 0.5 mM ATP, 10 min |
18±7 |
37±11 |
48±9 |
| G-T, 0.5 mM ATP, 10 sec |
21±9 |
31±8 |
47±9 |
| G-T, 0.5 mM ATP, 10 sec on ice |
21±9 |
26±6 |
50±7 |
| G-T, 0.5 mM ADP, 10 min |
34±3 |
19±3 |
47±4 |
| G-T, 0.5 mM AMPPNP, 10 min |
20±13 |
32±13 |
47±10 |
| Homoduplex, no nucleotide, 10 min |
17±10 |
40±15 |
51±16 |
| G-T, no nucleotide, EcoRI bound, 10 min |
27±9 |
23±3 |
47±9 |
| G-T, 0.5 mM ATP, EcoRI bound, 10 min |
16±4 |
31±9 |
50±12 |
| Values represent mean±s.d. |
| MutS (100 nM) and 1120-bp G-T mismatch/homoduplex DNA (20 nM) that contained biotin at both ends and had been previously bound with monovalent streptavidin were incubated in 20 mM Tris–HCl (pH 7.5), 100 mM K+glutamate, 5 mM MgCl2, and 0.4 mM DTT in the absence or presence of different nucleotides. All incubations were at room temperature (23°C) unless otherwise indicated. At the times shown, samples were deposited on APS-mica and the percentage of the DNA length corresponding to the short leg, long leg, and loop was determined from AFM images. For each experimental condition, about 50–60 DNAs with loops formed on them were analysed to determine length distributions. The data represent the mean values±s.d. of the Gaussian distributions of the lengths of the short leg, loop contour, and long leg. |
