TABLE 1.
Growth phenotype of cells expressing Gly mutants For testing resistance to toxic compounds, E. coli DH5α cells transformed with the various mutants were grown overnight at 37 °C on solid media containing toxic compounds as described under “Experimental Procedures.” Growth level of the cells was estimated compared to cell growth of cells transformed with wild type EmrE as positive control and pT7-7 (empty vector) as negative control. The plus symbol is assigned to cells able to grow as well as wild type EmrE under the same conditions. The lack of growth under these conditions is defined as the minus sign. Growth levels between that of wild type EmrE and the empty vector-transformed cells is marked with a +/– sign. Very low, yet detectable resistance is marked as a +/- -.
|
Mutation
|
Growth in presence of substrate
|
||
|---|---|---|---|
| Methyl viologen | Ethidium bromide | Acriflavine | |
| A | |||
| G8C | + | + | +/– |
| G9C | + | + | + |
| G17C | – | – | – |
| G26C | + | +/– | +/– |
| G35C | + | + | + |
| G57C | + | +/– | +/– |
| G65C | + | +/– | – |
| G67C | – | – | – |
| G77C | + | + | + |
| G80C | + | + | +/– |
| G90C | – | – | – |
| G97C | – | – | – |
| B | |||
| G17A/C/P | – | – | – |
| G67A/C/P | – | – | – |
| G90A | + | +/– | – |
| G90C/P | – | – | – |
| G97A | +/- - | – | – |
| G97C/P | – | – | – |