Targeted disruption of the PD78 gene (traF) reduces pheromone-inducible conjugal transfer of the bacteriocin plasmid pPD1 in Enterococcus faecalis.

Bacterial sex pheromone, cPD1, induces sexual aggregation of Enterococcus faecalis harboring the bacteriocin plasmid, pPD1, and enables pPD1 to transfer at high frequency in a liquid culture. PD78 is a cPD1-inducible cell surface protein encoded by pPD1. The PD78 gene, traF, was disrupted by homologous recombination between pPD1 and an artificial vector having a deletion in the middle portion of traF. The disruption of traF did not affect the cPD1-inducible aggregation but reduced the transfer frequency of pPD1 to 2% of the wild-type level.