Table 2.
Complementation of Bacillus subtilis SSB318 RNase P mutant strains by Escherichia coli rnpB (cell doubling times given in minutes)
| rnpB gene source | Promoter* | IPTG | No IPTG |
|---|---|---|---|
|
B. subtilis W168 (wild type) | |||
| W168 |
B.s. native |
57±2 |
56±2 |
| W168+pMAP65‡ |
B.s. native |
62±2 |
65±2 |
| |
|
|
|
|
B. subtilis SSB318 (Pspac:rnpB) | |||
| SSB318 |
spac |
67±3 |
— |
| SSB318+pMAP65‡ |
spac |
81±6 |
— |
| |
|
|
|
|
Multicopy | |||
| pHY300 (empty plasmid) |
None |
69±4 |
— |
| pHY300-BsrnpB |
B.s. native |
49±1 |
49±2 |
| pHY300-EcrnpB |
E.c. native |
52±2 |
60±2 |
| pHY300-EcrnpB |
B.s. native |
58±3 |
63±3 |
| |
|
|
|
|
Single copy | |||
| pDG364§ |
None |
63±3 |
— |
| SSB318EcrnpB∥ |
B.s. native |
52±1 |
57±1 |
| SSB318EcrnpB+pMAP65‡ | B.s. native | 56±2 | 64±4 |
| RNase P, ribonuclease P; IPTG, isopropyl-β-D-thiogalactoside; —: no growth at all; for determination of cell doubling times, see the supplementary information online. | |||
| *Promoter used for the respective rnpB gene; B.s. native and E.c. native, native rnpB promoters from B. subtilis and E. coli, respectively. | |||
| ‡Plasmid pMAP65 (pUB110 lacI; Petit et al, 1998) was used to overexpress the lac repressor to fully silence expression from the spac promoter in strain SSB318. | |||
| §Vector used for chromosomal integration into the amyE locus. | |||
| ∥E. coli rnpB integrated into the amyE locus under control of the native B. subtilis rnpB promoter and terminator. | |||