title: Phage associated bacteriocins reveal a novel mechanism for bacteriocin diversification in Klebsiella.
abstract: Ninety-six isolates of Klebsiella pneumoniae and K. oxytoca were recovered from wild mammals in Australia. 14.6% of these bacteria produce killing phenotypes that suggest the production of bacteriocin toxins. Cloning and sequencing of the gene clusters encoding two of these killing phenotypes revealed two instances of a bacteriocin associated with a bacteriophage gene, the first such genetic organization described. The newly identified klebicin C gene cluster was discovered in both K. pneumoniae and K. oxytoca. The newly identified klebicin D gene cluster was detected in K. oxytoca. Protein sequence comparisons and phylogenetic inference suggest that klebicin C is most closely related to the rRNase group of colicins (such as colicin E4), while klebicin D is most closely related to the tRNase group of colicins (such as colicin D). The klebicin C and D gene clusters have similar genetic and regulatory organizations. In both cases, an operon structure is inferred consisting of a phage-associated open reading frame and klebicin activity and associated immunity genes. This novel bacteriophage/bacteriocin organization may provide a novel mechanism for the generation of bacteriocin diversity in Klebsiella.
authors.affiliation: Department of Biology, University of Massachusetts Amherst, 611 North Pleasant Street, Amherst, MA, 01003, USA.
authors.forename: Milind
authors.initials: M
authors.lastname: Chavan
authors.forename: Hamid
authors.initials: H
authors.lastname: Rafi
authors.forename: John
authors.initials: J
authors.lastname: Wertz
authors.forename: Carla
authors.initials: C
authors.lastname: Goldstone
authors.forename: Margaret A
authors.initials: MA
authors.lastname: Riley
mesh_terms: D001430:Bacteriocins / Q000378:metabolism*; D001435:Bacteriophages / Q000235:genetics*; D001483:Base Sequence; D017931:DNA Primers; D007709:Klebsiella / Q000378:metabolism*; D016133:Polymerase Chain Reaction
chemical_list: D001430:Bacteriocins; D017931:DNA Primers