TABLE 5.
Abilities of novel dnaN alleles to complement the temperature sensitivity of the dnaN59(Ts) E. coli strain HC123
| Plasmid | dnaN allele | HC123 transformants/ml (42°C/30°C)a |
|---|---|---|
| pBR322 | None | <8.6 × 10−4 |
| pJRC210 | dnaN+ | 1.11 |
| pJRCHA-4.1 | Q61K | 0.71b |
| pJRCHA-5.1 | S107L | 1.02 |
| pJRCHA-8.1 | D150N | 1.10 |
| pJRCHA-5G11 | G157S | 0.86b |
| pJRCHA-8I11 | V170M | 0.95 |
| pJRCHA-7.1 | E202K | 1.01 |
| pJRCHA-6F11 | M204K | 0.92 |
| pJRCHA-6.2 | P363S | 0.95 |
a
The ratio of CFU obtained at 42°C to those obtained at 30°C was measured as described in Table 2, footnote c. Transformation efficiencies were on the order of ∼105 to ∼106 CFU per μg of plasmid DNA.
b
This strain formed small colonies at 42°C, suggesting that the plasmid was slightly less efficient than pJRC210 at suppressing the temperature sensitivity of E. coli HC123.