Phage associated bacteriocins reveal a novel mechanism for bacteriocin diversification in Klebsiella.
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.
Chavan
Milind
M
Department of Biology, University of Massachusetts Amherst, 611 North Pleasant Street, Amherst, MA, 01003, USA.
Rafi
Hamid
H
Wertz
John
J
Goldstone
Carla
C
Riley
Margaret A
MA
D001430:Bacteriocins / Q000378:metabolism*; D001435:Bacteriophages / Q000235:genetics*; D001483:Base Sequence; D017931:DNA Primers; D007709:Klebsiella / Q000378:metabolism*; D016133:Polymerase Chain Reaction
D001430:Bacteriocins; D017931:DNA Primers