TABLE 3.
ComQ and pre-ComX exchange experimentsa
| Plasmid | comQ | comX | β-Galactosidase activity (U/mg) in tester strain:
|
||
|---|---|---|---|---|---|
| RO-H-1 | RO-B-2 | RO-E-2 | |||
| pED409 | RO-B-2 | RO-B-2 | 48 | 210 | ND |
| pED433 | RO-B-2 | RO-H-1 | 1 | 0 | ND |
| pED368 | RO-H-1 | RO-H-1 | 254 | 7 | ND |
| pED434 | RO-H-1 | RO-B-2 | 43 | 112 | ND |
| pED413 | RO-E-2 | RO-E-2 | 21 | ND | 270 |
| pET-QH1/XE2 | RO-H-1 | RO-E-2 | 23 | ND | 72 |
| pED622 | RO-H-1 | RO-H-1/RO-E-2 | 22 | ND | 122 |
a
RO-H-1 (BD2962), RO-B-2 (BD2983), and RO-E-2 (BD3020) tester strains were grown in competence medium in the presence of partially purified pheromones (1:1,000 dilutions) produced by the indicated constructs. β-Galactosidase assays were performed on samples collected 2 h after sporulation and expressed as units per milligram of protein. Values represent the average of at least three determinations with a variation of no more than 10% from the mean. ND, not done.