TABLE 1.

Conjugative DNA transfer complementationa

StrainRelevant genotypeTransfer frequency (no. of transconjugants/ 100 donors)
JS10HMS174/pOX38T0.2
JS11HMS174/pOX38TΔtraI<2 × 10−6b
HMS174/pOX38TΔtraI/pET11c-traI0.03
HMS174/pOX38TΔtraI/pET11d-traIY16V<1 × 10−5b
HMS174/pOX38TΔtraI/pET11d-traIK998M<7 × 10−4b
HMS174/pOX38TΔtraI/pET3c-traIΔ252<8 × 10−6b
  • a Complementation assays were performed as described in Materials and Methods, using the indicated donor cell strain and JS4 as the recipient cell strain. All donor strains are HMS174 [FrecA1 hsdR (rK12 mK12+) (Rifr)] containing the indicated plasmid(s).

  • b No transconjugants were detected in any experiment. This value represents the sensitivity of the complementation assay and was determined by assuming there was a single transconjugant in the experiment. The actual transfer frequency may be much lower.