Table 2.
Summary of HslU mutants
| Peptide | Casein | SulA | ATPase | Hexamer | Comments | |
|---|---|---|---|---|---|---|
| Wild type | ++++ | ++++ | ++++ | ++++ | ++++ | |
| ATP-binding site mutants | ||||||
| K80T | + | ++ | ++++ | ++++ | ++ | |
| E286Q | ++ | ++ | ++ | ++++ | +++ | ATP-bound (structure)* |
| E321Q | − | − | − | − | ++++ | |
| R325E | − | − | − | − | − | ATP-bound (structure)* |
| R393A | − | − | − | − | ++ | ATP-bound (CD)* |
| I domain mutants | ||||||
| Δ137–150 | ++++ | ++++ | ++++ | ++++ | ++++ | 2 Gly linker |
| Δ175–209 | ++++ | ++++ | − | ++++ | ++++ | 2 Gly linker |
| Δ111–239 | +++ | +++ | − | +++ | ++++ | 3 Gly linker |
| Contact region in the EM mode | ||||||
| E266Q | ++++ | ++++ | ++++ | ++++ | ++++ | |
| E266Q/E385K | ++++ | ++++ | ++++ | ++++ | ++++ | |
| I312W | +++++ | +++++ | +++++ | +++++ | ++++ | |
| Ins(264, 265) | ++++ | ++++ | − | ++++ | ++++ | 5 Gly insertion |
| Ins(311, 312) | − | − | − | + | ++ | 5 Gly insertion |
| Ins(387, 388) | ++++ | +++ | − | +++++ | − | 5 Gly insertion† |
| Ins(435, 436) | NA | NA | NA | NA | NA | Insoluble, 5 Gly insertion |
| Δ432–443 | NA | NA | NA | NA | NA | Insoluble, C-term deletion |
| E436A/D437A | +++ | ND | ND | ND | ++++ | |
| E436K/D437K | +++ | ++++ | − | ++++ | ++++ | Charge reversal |
| Hexamer pore mutants | ||||||
| E88Q | ++ | − | − | ++++ | ++++ | |
| E88Q/E266Q | ++ | − | − | ++++ | ++++ | |
| Y91G | +++ | +++ | − | ++++ | ++++ | |
| V92G | ++++ | ++++ | − | ++++ | +++ | |
| G93A | + | + | − | ++ | ++++ | |
| E95W | ++++ | ++++ | + | ++++ | +++ | |
| Δ88–92 | − | − | − | − | ++ | 3 Gly linker |
| Δ89–92 | ++ | ++ | − | ++ | +++ | 1 Gly linker |
The values are relative to the wild-type HslU activity or hexamer content as a 100% (++++, 80–100%; +++, 60–80%; ++, 40–60%; +, 20–40%; −, <20%); NA, not applicable; ND, not determined.
*
Unpublished results.
† Hexamer in the presence of exogenous nucleotide.