TABLE 5.
Effect of overexpression of DksA on rne-R169Q,ΔCTH and ΔrppH rne-ΔCTH lethalitiesa
| Genotype | No. of Lac− colonies/total (ratio) for the indicated mutations |
|
|---|---|---|
| rne-R169Q,ΔCTH | ΔrppH rne-ΔCTH | |
| relA+ spoT+/pHR53 | 0/186 (<0.005) | 0/106 (<0.009) |
| relA+ spoT+/pJK537b | 17/138 (0.12) | 2/265 (0.007)c |
| relA1 spoT+/pHR53 | 0/203 (<0.005) | 0/180 (<0.005) |
| relA1 spoT+/pJK537b | 32/204 (0.14) | 14/320 (0.044)c |
a
The shelter plasmid loss assay for strains carrying pHYD1613 and pHYD2373 (rne-R169Q,ΔCTH) or only pHYD1613 (ΔrppH rne-ΔCTH) was done as described in the legend to Fig. 1. The strains carrying either pHR53 or pJK537 employed were as follows: rows 1 and 2, GJ15233 and GJ16022 for rne-R169Q,ΔCTH and ΔrppH rne-ΔCTH, respectively; rows 3 and 4, GJ14175 and GJ14157 for rne-R169Q,ΔCTH and ΔrppH rne-ΔCTH, respectively.
b
Overexpression of the dksA gene from this plasmid is brought about by the non-feedback-regulated promoter present upstream from the native dksA promoter (88).
c
The Lac− colonies are considered inviable, as they did not grow or revive upon restreaking.