Protection against bacteriocin 28b in<i>Serratia matcescens</i>is apparently not related to the expression of an immunity gene

Viejo, Margarita Beatriz; Enfedaque, Josefina; Guasch, Joan Francesc; Ferrer, Santiago; Regué, Miguel

doi:10.1139/m95-030

Cited by 5 publications

(7 citation statements)

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“…The bacteriocin 28b system has several unique features: the structural gene appears to be located on the chromosome (11), the SOS induction of bss transcription requires a transcription activator (8), and no colicin immunity-like gene was found downstream of the structural gene (29). The apparent absence of an immunity gene suggested that bacteriocin-producing S. marcescens could avoid killing by lacking appropriate bacteriocin receptors (29).…”

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Cloning and characterization of two Serratia marcescens genes involved in core lipopolysaccharide biosynthesis

et al. 1996

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Bacteriocin 28b from Serratia marcescens binds to Escherichia coli outer membrane proteins OmpA and OmpF and to lipopolysaccharide (LPS) core (J. Enfedaque, S. Ferrer, J. F. Guasch, J. Tomás, and M. Requé, Can. J. Microbiol. 42:19-26, 1996). A cosmid-based genomic library of S. marcescens was introduced into E. coli NM554, and clones were screened for bacteriocin 28b resistance phenotype. One clone conferring resistance to bacteriocin 28b and showing an altered LPS core mobility in polyacrylamide gel electrophoresis was found. Southern blot experiments using DNA fragments containing E. coli rfa genes as probes suggested that the recombinant cosmid contained S. marcescens genes involved in LPS core biosynthesis. Subcloning, isolation of subclones and Tn5tac1 insertion mutants, and sequencing allowed identification of two apparently cotranscribed genes. The deduced amino acid sequence from the upstream gene showed 80% amino acid identity to the KdtA protein from E. coli, suggesting that this gene codes for the 3-deoxy-manno-octulosonic acid transferase of S. marcescens. The downstream gene (kdtX) codes for a protein showing 20% amino acid identity to the Haemophilus influenzae kdtB gene product. The S. marcescens KdtX protein is unrelated to the KdtB protein of E. coli K-12. Expression of the kdtX gene from S. marcescens in E. coli confers resistance to bacteriocin 28b.

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Cloning and characterization of two Serratia marcescens genes involved in core lipopolysaccharide biosynthesis

et al. 1996

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“…Despite the homology found between bacteriocin 28b and the pore-forming colicins, bacteriocin 28b is chromosomally encoded and no immunity or release genes are found downstream from the structural gene (21,55). In this work we present results suggesting that bacteriocin 28b production by S. marcescens upon mitomycin induction is mediated by a transcriptional activator whose own transcription is SOS dependent.…”

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confidence: 72%

“…Upon standard mitomycin induction about one-third of the bacteriocinogenic activity was found bound to the S. marcescens cell surface, and higher levels of mitomycin induction (Ͼ1 g/ml) caused culture lysis, although no gene involved in bacteriocin 28b release has been found nearby the bss gene in the S. marcescens chromosome (55). Bacteriocinogenic activity was detected only in the cytoplasmic fraction in E. coli strains harboring the bss gene on a recombinant plasmid (54,55).…”

Section: Discussionmentioning

confidence: 99%

“…Bacteriocinogenic activity was detected only in the cytoplasmic fraction in E. coli strains harboring the bss gene on a recombinant plasmid (54,55). Since a holin-lysozyme system is used by most bacteriophages to release its progeny from the infected cells (58), it is tempting to speculate that the regA and regB gene products could be somehow involved in bacteriocin 28b release in S. marcescens.…”

Section: Discussionmentioning

confidence: 99%

“…The cyclic AMP receptor protein-cyclic AMP complex is involved in cloacin DF13 and colicin E1 transcription regulation (42, 52,53). Colicin E1, E2, E3, K, and D production increases in anaerobic conditions (32), and the Fnr protein has been shown to mediate this effect in colicin E1 (15).Despite the homology found between bacteriocin 28b and the pore-forming colicins, bacteriocin 28b is chromosomally encoded and no immunity or release genes are found downstream from the structural gene (21,55). In this work we present results suggesting that bacteriocin 28b production by S. marcescens upon mitomycin induction is mediated by a transcriptional activator whose own transcription is SOS dependent.…”

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Genetic evidence for an activator required for induction of colicin-like bacteriocin 28b production in Serratia marcescens by DNA-damaging agents

et al. 1996

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Bacteriocin 28b production is induced by mitomycin in wild-type Serratia marcescens 2170 but not in Escherichia coli harboring the bacteriocin 28b structural gene (bss). Studies with a bss-lacZ transcriptional fusion showed that mitomycin increased the level of bss gene transcription in S. marcescens but not in the E. coli background. A S. marcescens Tn5 insertion mutant was obtained (S. marcescens 2170 reg::Tn5) whose bacteriocin 28b production and bss gene transcription were not increased by mitomycin treatment. Cloning and DNA sequencing of the mutated region showed that the Tn5 insertion was flanked by an SOS box sequence and three genes that are probably cotranscribed (regA, regB, and regC). These three genes had homology to phage holins, phage lysozymes, and the Ogr transcriptional activator of P2 and related bacteriophages, respectively. Recombinant plasmid containing this wild-type DNA region complemented the reg::Tn5 regulatory mutant. A transcriptional fusion between a 157-bp DNA fragment, containing the apparent SOS box upstream of the regA gene, and the cat gene showed increased chloramphenicol acetyltransferase activity upon mitomycin treatment. Upstream of the bss gene, a sequence similar to the consensus sequence proposed to bind Ogr protein was found, but no sequence similar to an SOS box was detected. Our results suggest that transcriptional induction of bacteriocin 28b upon mitomycin treatment is mediated by the regC gene whose own transcription would be LexA dependent.Serratia marcescens has been shown to produce bacteriocins upon induction with DNA-damaging agents (50). These bacteriocins have been classified into two groups (23): fraction 1 bacteriocins are active against Escherichia coli but not against S. marcescens, and fraction 2 bacteriocins are active against S. marcescens but not against E. coli (50). Bacteriocins belonging to fraction 1 are simple polypeptides that resemble colicins (50). Only colicin-like bacteriocins L and 28b have been studied in some detail. Bacteriocin L from S. marcescens JF246 has been isolated and characterized, and the effects of this bacteriocin on the incorporation of labelled leucine and thymidine and on the cellular levels of ATP in E. coli were similar to those produced by pore-forming colicins (17,18,40). On the other hand, the bacteriocin 28b structural gene (bss) has been cloned and sequenced, and the predicted amino acid sequence of the C-terminal part of this bacteriocin has been shown to have a high degree of similarity to the C-terminal domains of pore-forming colicins (56). The two bacteriocins are very closely related, if not the same, and similar bacteriocins are produced by most S. marcescens biotypes (21).Colicin production is induced by mitomycin and other DNAdamaging agents (38). Determinants for colicin production studied so far are encoded by either small high-copy-number colicinogenic plasmids (type I) or large low-copy-number colicinogenic plasmids (type II) (38). An important feature of these plasmids is that they confer on their host...

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Colicins—Exocellular lethal proteins ofEscherichia coli

Šmarda

Šmajs

1998

Folia Microbiol

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Colicins are toxic exoproteins produced by bacteria of colicinogenic strains of Escherichia coli and some related species of Enterobacteriaceae, during the growth of their cultures. They inhibit sensitive bacteria of the same family. About 35% E. coli strains appearing in human intestinal tract are colicinogenic. Synthesis of colicins is coded by genes located on Col plasmids. Until now more than 34 types of colicins have been described, 21 of them in greater detail, viz. colicins A, B, D, E1-E9, Ia, Ib, JS, K, M, N, U, 5, 10. In general, their interaction with sensitive bacteria includes three steps: (1) binding of the colicin molecule to a specific receptor in the bacterial outer membrane; (2) its translocation through the cell envelope; and (3) its lethal interaction with the specific molecular target in the cell. The classification of colicins is based on differences in the molecular events of these three steps.

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Protection against bacteriocin 28b inSerratia matcescensis apparently not related to the expression of an immunity gene

Cited by 5 publications

References 31 publications

Cloning and characterization of two Serratia marcescens genes involved in core lipopolysaccharide biosynthesis

Cloning and characterization of two Serratia marcescens genes involved in core lipopolysaccharide biosynthesis

Genetic evidence for an activator required for induction of colicin-like bacteriocin 28b production in Serratia marcescens by DNA-damaging agents

Colicins—Exocellular lethal proteins ofEscherichia coli

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