TABLE 3.
Effects of mutations in Tra1 on R27 conjugation
| R27 mutanta in the donor strain | Transferb phenotype of mutantc | Relative conjugation frequency of R27 mutant (%)d | Relative conjugation frequency during complementation (%)e | Relative conjugation frequency of R27 with overexpressed transfer proteinf (%) | Plaque with Hgalg |
|---|---|---|---|---|---|
| orf115 | + | 120 | N/D | N/D | + |
| orf116 | + | 130 | N/D | N/D | + |
| traI | − | 0 | 24 | 23 | + |
| orf118 | + | 100 | N/D | N/D | + |
| traG | − | 0 | 5 | 30 | + |
| traI | − | 0 | 5 | 100 | + |
| orf121 | + | 14 | N/D | N/D | + |
| traH | − | 0 | 83 | 97 | + |
| trhR | − | 0 | 221 | 177 | − |
| trhY | − | 0 | 0.2 | 217 | − |
| trhX | + | 16 | N/D | N/D | + |
| trhF | − | 0 | 0.5 | 65 | − |
| traH | − | 0 | 0.3 | 79 | − |
| trhG | − | 0 | 136 | 77 | − |
Gene designation according to complete sequence of R27 (30) or this study. Donor strain was DY330R.
Ability of mutant to transfer via conjugation. Detectable matings scored as “+”, and nondetectable (<10−8 transconjugants/donor) scored as “−.”
cat cassette introduced into gene by either random transposon mutagenesis or homologous recombination as described in Materials and Methods.
Transfer frequency of R27 mutant relative to R27 [(R27 mutant frequency/R27 frequency) × 100%]. Due to the inherent variation of R27 transfer frequency, relative frequency was determined using the R27 transfer frequency for each experiment. R27 transferred with an average frequency of 5 × 10−1 transconjugants/donor. Values represent the average values of two independent experiments.
Restoration of conjugation by complementation in trans using a cloned gene (see Table 1); N/D, not determined. Transconjugants/donor cell after 18-h liquid mating with recipient DY330N, as described in Materials and Methods.
Designated transfer protein was overexpressed in donor containing R27 during conjugation assay. Relative transfer frequency of R27 with transfer protein/R27 for each experiment. Values represent the average value from two independent experiments.
Ability of H-pilus-specific RNA bacteriophage to form plaques with E. coli harboring designated mutant of R27 (agar spot test). E. coli containing R27 forms plaques when infected with Hgal.