title: R-type bacteriocins in related strains of Xenorhabdus bovienii: Xenorhabdicin tail fiber modularity and contribution to competitiveness.
abstract: R-type bacteriocins are contractile phage tail-like structures that are bactericidal towards related bacterial species. The C-terminal region of the phage tail fiber protein determines target-binding specificity. The mutualistic bacteria Xenorhabdus nematophila and X. bovienii produce R-type bacteriocins (xenorhabdicins) that are selectively active against different Xenorhabdus species. We analyzed the P2-type remnant prophage clusters in draft sequences of nine strains of X. bovienii The C-terminal tail fiber region in each of the respective strains was unique and consisted of mosaics of modular units. The region between the main tail fiber gene (xbpH1) and the sheath gene (xbpS1) contained a variable number of modules encoding tail fiber fragments. DNA inversion and module exchange between strains was involved in generating tail fiber diversity. Xenorhabdicin-enriched fractions from three different X. bovienii strains isolated from the same nematode species displayed distinct activities against each other. In one set of strains, the strain that produced highly active xenorhabdicin was able to eliminate a sensitive strain. In contrast, xenorhabdicin activity was not a determining factor in the competitive fitness of a second set of strains. These findings suggest that related strains of X. bovienii use xenorhabdicin and additional antagonistic molecules to compete against each other.
authors.affiliation: Department of Biological Sciences, University of Wisconsin, Milwaukee, WI 53211, USA.
authors.forename: Kristin
authors.initials: K
authors.lastname: Ciezki
authors.affiliation: Department of Bacteriology, University of Wisconsin, Madison, WI 53706, USA.|Department of Microbiology, Yale University, New Haven, CT 06519, USA.
authors.forename: Kristen
authors.initials: K
authors.lastname: Murfin
authors.affiliation: Department of Bacteriology, University of Wisconsin, Madison, WI 53706, USA.|Department of Microbiology, University of Tennessee-Knoxville, TN 37996, USA.
authors.forename: Heidi
authors.initials: H
authors.lastname: Goodrich-Blair
authors.affiliation: Department of Entomology, University of Arizona, Tucson, AZ 85721, USA.
authors.forename: S Patricia
authors.initials: SP
authors.lastname: Stock
authors.affiliation: Department of Biological Sciences, University of Wisconsin, Milwaukee, WI 53211, USA sforst@uwm.edu.
authors.forename: Steven
authors.initials: S
authors.lastname: Forst
mesh_terms: D000818:Animals; D000900:Anti-Bacterial Agents / Q000378:metabolism / Q000494:pharmacology; D000898:Antibiosis; D001430:Bacteriocins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism* / Q000494:pharmacology; D001435:Bacteriophages; D004269:DNA, Bacterial / Q000235:genetics; D016680:Genome, Bacterial; D017376:Viral Tail Proteins / Q000737:chemistry / Q000235:genetics*; D020593:Xenorhabdus / Q000166:cytology / Q000187:drug effects / Q000235:genetics* / Q000378:metabolism*
chemical_list: D000900:Anti-Bacterial Agents; D001430:Bacteriocins; D004269:DNA, Bacterial; D017376:Viral Tail Proteins
keywords: Xenorhabdus; antibiotics; bacteriocins; competition; phage tail