Table 1.
Results for 3AB, 3B+7, 3B, and various mutants in chaperone assays
| aProtein and concentration | bFRET assay | b,cAgg | b,dP-T Ann. | eFRET rate constant (k) |
| 3AB (2 µM) | +++ | +++ | +++ | 0.79 ± 0.21 |
| 3AB-Y90 > A (2 µM) | + | − | − | ND |
| 3AB-R104 > E (2 µM) | − | ND | − | ND |
| 3AB-Y90A/R104E (2 µM) | − | − | − | ND |
| 3B (100 µM) | − | − | − | 0.030 ± 0.001 |
| f3B+7 (100 µM) | +++ | ++ | ++ | 0.59 ± 0.07 |
| 3B+7-K81A (100 µM) | + | ND | ND | 0.13 ± 0.02 |
| 3B+7-F83A (100 µM) | + | ND | ND | 0.095 ± 0.049 |
| 3B+7-H86A (100 µM) | ++ | + | + | 0.21 ± 0.06 |
| 3B+7-Y90 > A (100 µM) | + | − | − | 0.15 ± 0.02 |
| 3B+7-R104A (100 µM) | − | ND | ND | ND |
| 3B+7-R104 > E (100 µM) | − | − | − | 0.031 ± 0.016 |
a
3B and 3B+7 proteins were made by chemical synthesis. All others were expressed and purified from E. coli.
b
+++, ∼75–100%; ++, ∼25–74%; +, ∼5–24%; −, <5%; ND, Not Determined. All relative to 3AB wild type. See Figure 2 for FRET unwinding assay.
c
Aggregation, determined by formation of a nucleic acid pellet using slow speed centrifugation (see Methods).
e
Rate constant (k) for FRET assays was determined as described in Methods. Results are an average of two or more experiments +/− standard deviation.
f
In FRET assays, 2 µM 3B+7 showed little stimulation while 8 µM showed some stimulation (+).