Plasmid Content of Streptococcus faecalis Strain 39-5 and Identification of a Pheromone (cPD1)-induced Surface Antigen

• Published in: Journal of general microbiology Vol. 129; no. 4; pp. 1207 - 1215
• Main Authors: Yagi, Y, Kessler, R. E, Shaw, J. H, Lopatin, D. E, An, F, Clewell, D. B
• Format: Journal Article
• Language: English
• Published: England Soc General Microbiol 01.04.1983
• Subjects: Animals; Antigens, Surface - genetics; Calcium; Chromosome Mapping; Conjugation, Genetic; Enterococcus faecalis - genetics; Enterococcus faecalis - immunology; Immune Sera; Pheromones - genetics; Pheromones - immunology; Phosphates; Plasmids
• ISSN: 0022-1287; 1350-0872; 1465-2080
• DOI: 10.1099/00221287-129-4-1207

The Dental Research Institute and the Departments of Oral Biology and Microbiology, Schools of Dentistry and Medicine, The University of Michigan, Ann Arbor, Michigan 48109, U.S.A. ABSTRACT SUMMARY: Streptococcus faecalis 39-5 is a haemolytic, bacteriocinogenic strain harbouring six plasmids. One of these plasmids, pPD1 (36.4 MDa1) determines a bacteriocin and encodes a conjugative response to the sex pheromone cPD1 excreted by recipient (plasmid-free) strains. The pheromone response is characterized by the formation of mating aggregates of donors (responders) with recipients. Aggregation required the presence of phosphate and divalent cations and was inhibited by agents or conditions that destroy protein structure. Aggregation was postulated to be due to synthesis of a new proteinaceous molecule on the donor cell surface. Referred to as ‘aggregation substance’, such a material was identified and found to exhibit antigenic properties not associated with uninduced cells; it could be detected by immunoelec-tron microscopy. Aggregation substance could be extracted from induced cells but not uninduced cells as demonstrated by crossed immunoelectrophoresis. Antibody raised against the aggregation substance controlled by pPD1 cross-reacted with aggregation substance determined by other plasmid systems which respond to pheromones unrelated to cPD1. Present address: The Upjohn Company, Kalamazoo, Michigan 49001, U.S.A.