Receptor Sites for R-type Pyocins and Bacteriophage E79 in the Core Part of the Lipopolysaccharide of Pseudomonas aeruginosa PAC1

Meadow, Pauline M.; Wells, Paul

doi:10.1099/00221287-108-2-339

Cited by 47 publications

(58 citation statements)

References 9 publications

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“…Recently, we and others found that bacteriophage~CTX is related to the R-type pyocins (11). The finding suggested that, as has been proposed for the R-type pyocins (25), lipopolysaccharide (LPS), not outer membrane protein, could be a receptor site for XCTX. The present study examined whether LPS could be the receptor for OCrX.…”

mentioning

confidence: 94%

“…While PML14 was sensitive to all types of R pyocins (Ri to R5) and 4CIX, its derivatives PML14e, PML14b, and PML14d were mutants with altered sensitivities to R pyocins (15, 33) and~CXX (11) ( Table 4). Since the proposed receptor site for R-type pyocins was the core region of LPS (25), these mutants should have some defects in their LPS cores. The R core of PML14 contained galactosamine, alanine, glucose, and rhamnose in a molar ratio of about 1:1:3:1 (Table 3) derivatives, 4CTX bound to PML14b and PML14d at a reduced efficiency.…”

Section: Characterizationmentioning

confidence: 99%

See 1 more Smart Citation

Identification of the lipopolysaccharide core region as the receptor site for a cytotoxin-converting phage, phi CTX, of Pseudomonas aeruginosa

1994

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A temperate phage, +CTX, is a cytotoxin-converting phage of Pseudomonas aeruginosa. In this study, we characterized the lipopolysaccharide (LPS) structures of 4CTX-resistant mutants derived from 4CTX-sensitive strains. 4CTX infectivity was neutralized by LPS preparations derived from sensitive strains but not by those from resistant strains. 4CTX-resistant mutants had lower-molecular-weight rough (R)-type LPS than the parental strains and lacked the reactivity of some anti-LPS core monoclonal antibodies. Some LPS core components were lacking or significantly decreased in the resistant mutants. These results suggested that a receptor site of the cytotoxin-converting phage +CTX was the LPS core region and that especially L-rhamnose and D-glucose residues in the outer core were involved in phage binding. The host range of +CTX was nearly 0-serotype dependent, probably because of the diversity of the LPS core structure among P. aeruginosa strains.+CTX bound to most strains of Homma serotypes A, G, and I but not to strains of serotypes B and E.Furthermore, we found that a genetic locus specifying 4)CTX sensitivity (and consequently participating in the biosynthesis of part of the LPS core) existed in or near the locus participating in the determination of 0-serotype specificity (somA), which has been mapped between leu-10 and eda-9001. 4CTX, as well as anti-LPS core monoclonal antibodies, will be a good tool for structural characterization of the P. aeruginosa LPS core region.Pseudomonas aeruginosa cytotoxin shows a wide range of cytotoxic activity against eukaryotic cells, especially leukocytes (9,22,31). Unlike other toxins and enzymes produced by P. aeruginosa, cytotoxin is not secreted into the culture medium. It is produced as a cell-associated procytotoxin, released into the medium during cell lysis, and then converted to an active cytotoxin by C-terminal processing (8,9,31).In previous studies (6,7,11), it was found that the gene encoding cytotoxin, clx, existed only in two of about 400 P. aeruginosa strains from various sources and that in both strains the genes existed on the genomes of the prophages. Furthermore, both of the bacteriophages isolated, which were phylogenetically closely related to each other (11), actually converted P. aeruginosa strains to cytotoxin producers by their lysogenization (7, 11). 4~CTX is one of the cytotoxin-converting phages isolated from strain PA158, a strong cytotoxin producer which has been widely used for the study of cytotoxin.Since 4~CTX could infect only some but not all P. aeruginosa strains (reference 6 and this study), the host range of 4)CTX seemed to depend on the presence of a specific receptor on the bacterial cell surface. However, the receptor site for CrX has not been revealed yet. Recently, we and others found that bacteriophage~CTX is related to the R-type pyocins (11). The finding suggested that, as has been proposed for the R-type pyocins (25), lipopolysaccharide (LPS), not outer membrane protein, could be a receptor site for XCTX. The present study examin...

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mentioning

confidence: 94%

Section: Characterizationmentioning

confidence: 99%

Identification of the lipopolysaccharide core region as the receptor site for a cytotoxin-converting phage, phi CTX, of Pseudomonas aeruginosa

1994

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“…The susceptibility of mutants to bacteriophages E79tv-1 and AP41 was determined by spot test (25). Crude AP41 was prepared by the method described by Meadow and Wells (25).…”

Section: Methodsmentioning

confidence: 99%

“…P. aeruginosa PAF41 was used as a producer strain for aeruginocin AP41 (35). Phages F116L and G101 were used for transduction (21,23), and phages E79tv-1 and aeruginocin AP41 were used for susceptibility tests (25). Plasmid FP5 with chromosome mobilization ability was used for conjugation (24).…”

Section: Methodsmentioning

confidence: 99%

Mutations producing resistance to norfloxacin in Pseudomonas aeruginosa

Hirai¹,

Suzue²,

Irikura³

et al. 1987

Antimicrob Agents Chemother

187

164

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Two genetically distinct classes of norfloxacin-resistant Pseudomonas aeruginosa PA04009 mutants were isolated spontaneously. Two norfloxacin resistance genes, nfxA and nfxB, were mapped between hex-9001 and leu-9005 and between pro-9031 and ilv-9023, respectively, on the P. aeruginosa PAO chromosome. The nfxA gene was shown to be an allele of nalA by transductional analysis with bacteriophage F116L. The nfxB mutant showed a 16-fold increase in resistance to norfloxacin and a slight increase in resistance to nalidixic acid. The nfxB mutant was unique in that it showed hypersusceptibility to beta-lactam and aminoglycoside antibiotics. This mutant had about a threefold-lower rate of norfloxacin uptake than that of the wild-type strain or nfxA mutant. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis of outer membrane proteins demonstrated the appearance of a 54,000-dalton protein in the nfxB mutant. These findings suggested that the norfloxacin resistance mechanism in the nfxB mutant might be an alteration in outer membrane permeability to norfloxacin.Norfloxacin and other new 4-quinolones show potent antibacterial activity against gram-negative and grampositive bacteria (11,14,20). They also have high in vitro and in vivo antibacterial activity against Pseudomonas aeruginosa strains that show a strong intrinsic resistance to various antimicrobial agents including older quinolones such as nalidixic acid (11,20,42). The high antibacterial activity of new quinolones might be due to their strong inhibitory action against DNA gyrase, a target enzyme of quinolones, which has been isolated from various bacteria including Pseudomonas aeruginosa (5,16,26,28,42).Drug resistance mediated by plasmids or transposons is a serious clinical problem. However, resistance to nalidixic acid and other quinolones in bacteria is due to chromosomal mutations (10,13,(16)(17)(18)32). Plasmids or transposons that carry quinolone resistance genes have not been found in bacteria (4). Several chromosomal mutations, gyrA, nalB, nalC (gyrB), and nalD, conferring nalidixic acid resistance were identified and mapped on the Escherichia coli K-12 chromosome (10,17,18). Recently, we (13) and Hooper et al. (16) identified norfloxacin resistance mutations (norA, norB, norC, nfxA, and nfxB) in E. coli K-12. norA and nfxA were alleles of gyrA encoding the A subunit of DNA gyrase, while norB, norC, and nfxB determined outer membrane permeability resistance to norfloxacin, were associated with a decrease in OmpF porin protein, and were mapped at 34 min, near 8 min, and at 20 to 22 min, respectively (13, 16). Two loci coding for resistance to nalidixic acid, nalA and nalB, have also been mapped on the P. aeruginosa PAO chromosome (32). It has been reported that DNA replication is resistant to nalidixic acid in permeabilized cells of nalA mutants and that nalB mutants cause a decrease of cell permeability to nalidixic acid and carbenicillin (32).To gain information on the resistance mechanisms to norfloxacin in P. aeruginosa, we isolated spontaneous...

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“…The phage-tail-like structure of R-type pyocins is not unique, since other genera produce similar bacteriocins (for example, serracin P from Serratia plymithicum) (293). R-type pyocins adsorb to LPS molecules at the cell surface (287,454) and then penetrate through the outer membrane by a process resembling phage contraction (232) before killing the target bacteria by membrane depolarization (635). The S-type pyocins that have been characterized so far are nonspecific endonucleases.…”

Section: Pyocinsmentioning

confidence: 99%

Colicin Biology

Cascales

Buchanan

Duché

et al. 2007

Microbiol Mol Biol Rev

985

1,324

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SUMMARY Colicins are proteins produced by and toxic for some strains of Escherichia coli. They are produced by strains of E. coli carrying a colicinogenic plasmid that bears the genetic determinants for colicin synthesis, immunity, and release. Insights gained into each fundamental aspect of their biology are presented: their synthesis, which is under SOS regulation; their release into the extracellular medium, which involves the colicin lysis protein; and their uptake mechanisms and modes of action. Colicins are organized into three domains, each one involved in a different step of the process of killing sensitive bacteria. The structures of some colicins are known at the atomic level and are discussed. Colicins exert their lethal action by first binding to specific receptors, which are outer membrane proteins used for the entry of specific nutrients. They are then translocated through the outer membrane and transit through the periplasm by either the Tol or the TonB system. The components of each system are known, and their implication in the functioning of the system is described. Colicins then reach their lethal target and act either by forming a voltage-dependent channel into the inner membrane or by using their endonuclease activity on DNA, rRNA, or tRNA. The mechanisms of inhibition by specific and cognate immunity proteins are presented. Finally, the use of colicins as laboratory or biotechnological tools and their mode of evolution are discussed.

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Receptor Sites for R-type Pyocins and Bacteriophage E79 in the Core Part of the Lipopolysaccharide of Pseudomonas aeruginosa PAC1

Cited by 47 publications

References 9 publications

Identification of the lipopolysaccharide core region as the receptor site for a cytotoxin-converting phage, phi CTX, of Pseudomonas aeruginosa

Identification of the lipopolysaccharide core region as the receptor site for a cytotoxin-converting phage, phi CTX, of Pseudomonas aeruginosa

Mutations producing resistance to norfloxacin in Pseudomonas aeruginosa

Colicin Biology

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