Genetic functions and cell-cell interactions in the pheromone-inducible plasmid transfer system of Enterococcus faecalis.
Pheromone-inducible plasmid transfer is a novel form of bacterial conjugation which has, to date, been observed only in Enterococcus (Streptococcus) faecalis. This process includes several important stages of interaction between the donor and recipient cell. The initial interaction is the transmission of a chemical signal from the recipient to the donor cell. Recent evidence has shown that the signal is in the form of a small hydrophobic peptide, which is capable of inducing a complex mating response in the donor cell at concentrations as low as 1-5 molecules per responder cell. Most E. faecalis strains produce multiple pheromones, each of which induces a response only in cells carrying a particular plasmid (or member of a family of related plasmids). Genetic functions ascribed to the pheromone response include: (i) cell-cell aggregation, which promotes initial close contact between mating cells; (ii) surface exclusion, which prevents plasmid transfer between aggregated donor cells; and (iii) highly efficient DNA transfer, which requires other unidentified functions in addition to aggregation. The first two processes appear to be mediated by proteinaceous surface antigens.
Dunny
G M
GM
Department of Microbiology, Immunology and Parasitology, New York State College of Veterinary Medicine, Cornell University, Ithaca 14853.
D000595:Amino Acid Sequence; D003227:Conjugation, Genetic; D013293:Enterococcus faecalis / Q000235:genetics*; D015964:Gene Expression Regulation, Bacterial; D008969:Molecular Sequence Data; D010675:Pheromones / Q000502:physiology*; D010957:Plasmids; D015398:Signal Transduction
D010675:Pheromones