title: An Rhs-like genetic element is involved in bacteriocin production by Pseudomonas savastanoi pv. savastanoi.
abstract: The main aim of this work was the identification of genetic determinants involved in bacteriocin production by strain ITM317 of Pseudomonas savastanoi pv. savastanoi, besides bacteriocin characterization. The bacteriocin was observed to be a heat-sensitive, high molecular weight proteinaceous compound. We identified a transposon (Tn5)-induced mutant which had lost its ability to produce the bacteriocin. The Tn5 insertion's responsibility for the above mutated phenotype was demonstrated by marker-exchange mutagenesis. An EcoRI DNA fragment, corresponding to the EcoRI Tn5-containing fragment of the mutant, was also cloned from the wild-type strain, and its introduction into the mutant complemented the mutation. Moreover, that fragment enabled bacteriocin production by P. s. pv. savastanoi ITM302, a strain not previously capable of doing so. DNA sequence analysis revealed that Tn5 insertion occurred in the mutant within a large ORF encoding a protein which showed similarity with proteins from the Rhs family. The DNA region including that ORF showed features which have been considered typical of the Rhs genetic elements previously identified in other bacteria but whose function is as yet unclear. The results of this study for the first time identify an Rhs-like element in P. s. pv. savastanoi, and for the first time indicate that an Rhs element is involved in bacteriocin production, also suggesting this possible function for Rhs genetic elements previously characterized in other bacteria.
authors.affiliation: Institute of Sciences of Food Production, Bari, Italy. angelo.sisto@ispa.cnr.it
authors.forename: Angelo
authors.initials: A
authors.lastname: Sisto
authors.forename: Maria Grazia
authors.initials: MG
authors.lastname: Cipriani
authors.forename: Maria
authors.initials: M
authors.lastname: Morea
authors.forename: Stella Lisa
authors.initials: SL
authors.lastname: Lonigro
authors.forename: Francesca
authors.initials: F
authors.lastname: Valerio
authors.forename: Paola
authors.initials: P
authors.lastname: Lavermicocca
mesh_terms: D000595:Amino Acid Sequence; D001426:Bacterial Proteins / Q000737:chemistry / Q000235:genetics; D001430:Bacteriocins / Q000096:biosynthesis* / Q000737:chemistry / Q000235:genetics / Q000302:isolation & purification; D001482:Base Composition; D004251:DNA Transposable Elements; D004269:DNA, Bacterial / Q000235:genetics / Q000302:isolation & purification*; D015246:Deoxyribonuclease EcoRI / Q000378:metabolism; D005798:Genes, Bacterial; D008969:Molecular Sequence Data; D016254:Mutagenesis, Insertional; D016366:Open Reading Frames; D010935:Plant Diseases / Q000382:microbiology; D010957:Plasmids / Q000235:genetics; D011549:Pseudomonas / Q000235:genetics* / Q000378:metabolism; D016415:Sequence Alignment; D017422:Sequence Analysis, DNA; D020539:Sequence Analysis, Protein
chemical_list: D001426:Bacterial Proteins; D001430:Bacteriocins; D004251:DNA Transposable Elements; D004269:DNA, Bacterial; D015246:Deoxyribonuclease EcoRI