TABLE 2.
Summary of RegA mutant proteins generated from the receiver domain and linker domain indicating RegA-CbbR (DNA) interactions (using probe-0) and DNA binding function manifested by the ability to bind probe-1234
| RegA protein | CbbR interaction (probe-0)a | DNA binding |
|
|---|---|---|---|
| Probe-1234b | Lowest [RegA] (nM)c | ||
| wt | + | +++ | 40 |
| Receiver domain | |||
| D20A/D21A | − | + | 160 |
| R27L | + | ++ | 40 |
| M32K | − | − | No binding |
| R35L | + | ++ | 40 |
| K49E | − | ++ | 40 |
| P57A | − | ++ | 40 |
| D63A(-P) | + | +++ | 40 |
| E67K | + | ++ | 40 |
| R79G | − | + | 40 |
| D84A | + | +++ | 40 |
| T91A | + | +++ | 40 |
| A97S | + | +++ | 40 |
| D109A | + | +++ | 40 |
| K113M | + | +++ | 40 |
| Linker | |||
| P134A | + | +++ | 40 |
a
For CbbR interaction, + denotes interaction and − denotes no interaction.
b
For DNA binding, +++ denotes RegA/promoter complex size comparable to wild-type RegA size, ++ denotes complex size reduced relative to wild-type RegA size, + denotes severe reduction of complex size relative to wild-type RegA size, and − denotes no DNA binding relative to wild-type RegA binding.
c
Lowest concentration of RegA that bound probe-1234.