201
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Yonezawa H, Kuramitsu HK. Genetic analysis of a unique bacteriocin, Smb, produced by Streptococcus mutans GS5. Antimicrob Agents Chemother 2005; 49:541-8. [PMID: 15673730 PMCID: PMC547247 DOI: 10.1128/aac.49.2.541-548.2005] [Citation(s) in RCA: 86] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
A dipeptide lantibiotic, named Smb, in Streptococcus mutans GS5 was characterized by molecular genetic approaches. The Smb biosynthesis gene locus is encoded by a 9.5-kb region of chromosomal DNA and consists of seven genes in the order smbM1, -T, -F, -M2, -G, -A, -B. This operon is not present in some other strains of S. mutans, including strain UA159. The genes encoding Smb were identified as smbA and smbB. Inactivation of smbM1, smbA, or smbB attenuated the inhibition of the growth of the indicator strain RP66, confirming an essential role for these genes in Smb expression. Mature Smb likely consists of the 30-amino-acid SmbA together with the 32-amino-acid SmbB. SmbA exhibited similarity with the mature lantibiotic lacticinA2 from Lactococcus lactis, while SmbB was similar to the mersacidin-like peptides from Bacillus halodurans and L. lactis. We also demonstrated that Smb expression is induced by the competence-stimulating peptide (CSP) and that a com box-like sequence is located in the smb promoter region. These results suggest that Smb belongs to the class I bacteriocin family, and its expression is dependent on CSP-induced quorum sensing.
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Affiliation(s)
- Hideo Yonezawa
- Department of Oral Biology, State University of New York, 3435 Main St., Buffalo, NY 14214, USA
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202
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Datta V, Myskowski SM, Kwinn LA, Chiem DN, Varki N, Kansal RG, Kotb M, Nizet V. Mutational analysis of the group A streptococcal operon encoding streptolysin S and its virulence role in invasive infection. Mol Microbiol 2005; 56:681-95. [PMID: 15819624 DOI: 10.1111/j.1365-2958.2005.04583.x] [Citation(s) in RCA: 128] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The pathogen group A Streptococcus (GAS) produces a wide spectrum of infections including necrotizing fasciitis (NF). Streptolysin S (SLS) produces the hallmark beta-haemolytic phenotype produced by GAS. The nine-gene GAS locus (sagA-sagI) resembling a bacteriocin biosynthetic operon is necessary and sufficient for SLS production. Using precise, in-frame allelic exchange mutagenesis and single-gene complementation, we show sagA, sagB, sagC, sagD, sagE, sagF and sagG are each individually required for SLS production, and that sagE may further serve an immunity function. Limited site-directed mutagenesis of specific amino acids in the SagA prepropeptide supports the designation of SLS as a bacteriocin-like toxin. No significant pleotrophic effects of sagA deletion were observed on M protein, capsule or cysteine protease production. In a murine model of NF, the SLS-negative M1T1 GAS mutant was markedly diminished in its ability to produce necrotic skin ulcers and spread to the systemic circulation. The SLS toxin impaired phagocytic clearance and promoted epithelial cell cytotoxicity, the latter phenotype being enhanced by the effects of M protein and streptolysin O. We conclude that all genetic components of the sag operon are required for expression of functional SLS, an important virulence factor in the pathogenesis of invasive M1T1 GAS infection.
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Affiliation(s)
- Vivekanand Datta
- Department of Pediatrics, Division of Infectious Diseases, University of California, San Diego, La Jolla, CA, USA
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203
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Korobov VP, Titova AV, Lemkina LM, Polyudova TV, Pan’kova NV. The dependence of the antibacterial effect of the polycationic peptide warnerin on the energy state of target cells. Microbiology (Reading) 2005. [DOI: 10.1007/s11021-005-0042-7] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022] Open
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204
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Elliot MA, Talbot NJ. Building filaments in the air: aerial morphogenesis in bacteria and fungi. Curr Opin Microbiol 2005; 7:594-601. [PMID: 15556031 DOI: 10.1016/j.mib.2004.10.013] [Citation(s) in RCA: 73] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
To disperse their spores to new sites, filamentous fungi and bacteria need to erect aerial filaments, which develop into fruiting bodies and spore-bearing structures. The first challenge to aerial development is breaking surface tension at an aqueous-air interface, and in both groups of microorganisms, surface-active proteins take part in the initiation of aerial morphogenesis. Comparative analysis of fungi and bacteria is providing new insights into the means by which aerial filamentation is accomplished.
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Affiliation(s)
- Marie A Elliot
- Department of Molecular Microbiology, John Innes Centre, Colney Lane, Norwich, NR4 7UH, UK.
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205
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Sahl HG, Pag U, Bonness S, Wagner S, Antcheva N, Tossi A. Mammalian defensins: structures and mechanism of antibiotic activity. J Leukoc Biol 2004; 77:466-75. [PMID: 15582982 DOI: 10.1189/jlb.0804452] [Citation(s) in RCA: 155] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
Antibiotic peptides are important effector molecules in host-parasite interactions throughout the living world. In vertebrates, they function in first-line host defense by antagonizing a wide range of microbes including bacteria, fungi, and enveloped viruses. The antibiotic activity is thought to be based on their cationic, amphipathic nature, which enables the peptides to impair vital membrane functions. Molecular details for such activities have been elaborated with model membranes; however, there is increasing evidence that these models may not reflect the complex processes involved in the killing of microbes. For example, the overall killing activity of the bacterial peptide antibiotic nisin is composed of independent activities such as the formation of target-mediated pores, inhibition of cell-wall biosynthesis, formation of nontargeted pores, and induction of autolysis. We studied the molecular modes of action of human defense peptides and tried to determine whether they impair membrane functions primarily and whether additional antibiotic activities may be found. We compared killing kinetics, solute efflux kinetics, membrane-depolarization assays, and macromolecular biosynthesis assays and used several strains of Gram-positive cocci as test strains. We found that membrane depolarization contributes to rapid killing of a significant fraction of target cells within a bacterial culture. However, substantial subpopulations appear to survive the primary effects on the membrane. Depending on individual strains and species and peptide concentrations, such subpopulations may resume growth or be killed through additional activities of the peptides. Such activities can include the activation of cell-wall lytic enzymes, which appears of particular importance for killing of staphylococcal strains.
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Affiliation(s)
- Hans-Georg Sahl
- Institute for Medical Microbiology and Immunology, University of Bonn, Germany.
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206
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Bhatti M, Veeramachaneni A, Shelef LA. Factors affecting the antilisterial effects of nisin in milk. Int J Food Microbiol 2004; 97:215-9. [PMID: 15541808 DOI: 10.1016/j.ijfoodmicro.2004.06.010] [Citation(s) in RCA: 80] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Revised: 06/04/2004] [Accepted: 06/08/2004] [Indexed: 10/26/2022]
Abstract
The ability of Listeria monocytogenes to proliferate in milk and the antilisterial activities of nisin are well documented. Although milk fat was reported to reduce the antimicrobial activities of nisin, there is little information on the influence of milk fat on the antilisterial activities of nisin in refrigerated milk, and whether pasteurization and homogenization influence these activities. Fresh, pasteurized, and homogenized milk samples (0.1%, 2.0%, and 3.5% fat) were treated with nisin (0-500 IU/ml) and challenged with 10(4) CFU/ml L. monocytogenes strain Scott A. The organism was most sensitive to nisin in skim milk, showing rapid decline in cell numbers to <10 CFU/ml after 12 days at 5 degrees C following treatment with 250 IU/ml. An initial decline in cell numbers in 2% and whole milk was followed by regrowth of the organism. Loss of the antilisterial effects of nisin was confirmed in homogenized whole milk, whether raw or pasteurized, but not in raw or pasteurized whole milk that was not homogenized. Tween 80, a nonionic emulsifier, partially counteracted the loss of the antilisterial activity of nisin, whereas lecithin, an anionic emulsifier, had no effect. These results demonstrate that the chemical composition and treatment of foods may play an important role in the antilisterial effects of nisin.
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Affiliation(s)
- Meena Bhatti
- Department of Nutrition and Food Science, Wayne State University, Detroit, MI 48202, USA
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207
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Kheadr E, Bernoussi N, Lacroix C, Fliss I. Comparison of the sensitivity of commercial strains and infant isolates of bifidobacteria to antibiotics and bacteriocins. Int Dairy J 2004. [DOI: 10.1016/j.idairyj.2004.04.010] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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208
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Growth conditions required for bacteriocin production by strains of Staphylococcus aureus. World J Microbiol Biotechnol 2004. [DOI: 10.1007/s11274-004-3626-x] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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209
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Abstract
Generations of chemists and biologists have conducted research on natural products and other metabolites produced by bacteria and other microorganisms. This has led to an explosion in knowledge concerning the mechanism by which such natural products are made, ultimately allowing custom redesign of many of these molecules for increased potency and selectivity as therapeutic drugs. Along the way, scientists have begun to appreciate that the bacterial world is teeming with life on a scale hardly conceivable, with constant communication within the bacterial world and with outside neighbors, such as plants and mammals. Only in recent years have some of the signaling molecules that comprise these elaborate forms of communication been characterized in any sort of chemical detail, which has in turn peaked interest in the intricate biology of this micro-world and its interactions with the macro-world.
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Affiliation(s)
- Gholson J Lyon
- Laboratory of Synthetic Protein Chemistry, The Rockefeller University, 1230 York Avenue, New York, NY 10021, USA
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210
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Hsu STD, Breukink E, Tischenko E, Lutters MAG, de Kruijff B, Kaptein R, Bonvin AMJJ, van Nuland NAJ. The nisin-lipid II complex reveals a pyrophosphate cage that provides a blueprint for novel antibiotics. Nat Struct Mol Biol 2004; 11:963-7. [PMID: 15361862 DOI: 10.1038/nsmb830] [Citation(s) in RCA: 396] [Impact Index Per Article: 19.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2004] [Accepted: 07/16/2004] [Indexed: 11/09/2022]
Abstract
The emerging antibiotics-resistance problem has underlined the urgent need for novel antimicrobial agents. Lantibiotics (lanthionine-containing antibiotics) are promising candidates to alleviate this problem. Nisin, a member of this family, has a unique pore-forming activity against bacteria. It binds to lipid II, the essential precursor of cell wall synthesis. As a result, the membrane permeabilization activity of nisin is increased by three orders of magnitude. Here we report the solution structure of the complex of nisin and lipid II. The structure shows a novel lipid II-binding motif in which the pyrophosphate moiety of lipid II is primarily coordinated by the N-terminal backbone amides of nisin via intermolecular hydrogen bonds. This cage structure provides a rationale for the conservation of the lanthionine rings among several lipid II-binding lantibiotics. The structure of the pyrophosphate cage offers a template for structure-based design of novel antibiotics.
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Affiliation(s)
- Shang-Te D Hsu
- Department of NMR Spectroscopy, Bijvoet Center for Biomolecular Research, Utrecht University, Padualaan 8, 3584CH Utrecht, The Netherlands
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211
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Stein T, Düsterhus S, Stroh A, Entian KD. Subtilosin production by two Bacillus subtilis subspecies and variance of the sbo-alb cluster. Appl Environ Microbiol 2004; 70:2349-53. [PMID: 15066831 PMCID: PMC383111 DOI: 10.1128/aem.70.4.2349-2353.2004] [Citation(s) in RCA: 56] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Eight different Bacillus subtilis strains and Bacillus atrophaeus were found to produce the bacteriocin subtilosin A. On the basis of the subtilosin gene (sbo) sequences two distinct classes of B. subtilis strains were distinguished, and they fell into the two B. subtilis subspecies (B. subtilis subsp. subtilis and B. subtilis subsp. spizizenii). The entire sequence of the subtilosin gene cluster of a B. subtilis subsp. spizizenii strain, B. subtilis ATCC 6633, was determined. This sequence exhibited a high level of homology to the sequence of the sbo-alb gene locus of B. subtilis 168. By using primer extension analysis the transcriptional start sites of sbo in B. subtilis strains ATCC 6633 and 168 were found to be 47 and 45 bp upstream of the sbo start codon, respectively. Our results provide insight into the incipient evolutionary divergence of the two B. subtilis subspecies.
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Affiliation(s)
- Torsten Stein
- Institut für Mikrobiologie, Johann Wolfgang Goethe-Universität, D-60439 Frankfurt am Main, Germany.
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212
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Dirix G, Monsieurs P, Dombrecht B, Daniels R, Marchal K, Vanderleyden J, Michiels J. Peptide signal molecules and bacteriocins in Gram-negative bacteria: a genome-wide in silico screening for peptides containing a double-glycine leader sequence and their cognate transporters. Peptides 2004; 25:1425-40. [PMID: 15374646 DOI: 10.1016/j.peptides.2003.10.028] [Citation(s) in RCA: 93] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/15/2003] [Accepted: 10/31/2003] [Indexed: 01/21/2023]
Abstract
Quorum sensing (QS) in Gram-negative bacteria is generally assumed to be mediated by N-acyl-homoserine lactone molecules while Gram-positive bacteria make use of signaling peptides. We analyzed the occurrence in Gram-negative bacteria of peptides and transporters that are involved in quorum sensing in Gram-positive bacteria. Many class II bacteriocins and inducing factors produced by lactic acid bacteria (LAB) and competence stimulating peptides (CSPs) synthesized by streptococci are processed by their cognate ABC-transporters during their secretion. During transport, a conserved leader sequence, termed the double-glycine motif (GG-motif), is cleaved off by the N-terminal domain of the transporter, which belongs to the Peptidase C39 protein family. Several peptides containing a GG-motif were recently described in Gram-negative bacteria (Trends Microbiol 2001;9:164-8). To screen for additional putative GG-motif containing peptides, an in silico strategy based on MEME, HMMER2.2 and Wise2 was designed. Using a curated training set, a motif model of the leader peptide was built and used to screen over 120 fully sequenced bacterial genomes. The screening methodology was applied at the nucleotide level as probably many small peptide genes have not been annotated and may be absent from the non-redundant databases. It was found that 33% of the screened genomes of Gram-negative bacteria contained one or more transporters carrying a Peptidase C39 domain, compared to 44% of the genomes of Gram-positive bacteria. The transporters can be subdivided into four classes on the basis of their domain organization. Genes coding for putative peptides containing 23-142 amino acids and a GG-motif were found in close association with genes coding for Peptidase C39 domain containing proteins. These peptides show structural similarity to bacteriocins and peptide pheromones of Gram-positive bacteria. The possibility of signal transduction based on peptide signaling in Gram-negative bacteria is discussed.
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Affiliation(s)
- G Dirix
- Centre of Microbial and Plant Genetics, Kasteelpark Arenberg 20, B-3001 Heverlee, Belgium
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213
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Lyon GJ, Novick RP. Peptide signaling in Staphylococcus aureus and other Gram-positive bacteria. Peptides 2004; 25:1389-403. [PMID: 15374643 DOI: 10.1016/j.peptides.2003.11.026] [Citation(s) in RCA: 243] [Impact Index Per Article: 12.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/24/2003] [Accepted: 11/13/2003] [Indexed: 10/26/2022]
Abstract
There are two basic types of bacterial communication systems--those in which the signal is directed solely at other organisms and those in which the signal is sensed by the producing organism as well. The former are involved primarily in conjugation; the latter in adaptation to the environment. Gram-positive bacteria use small peptides for both types of signaling, whereas Gram-negative bacteria use homoserine lactones. Since adaptation signals are autoinducers the response is population-density-dependent and has been referred to as "quorum-sensing". Gram-negative bacteria internalize the signals which act upon an intracellular receptor, whereas Gram-positive bacteria use them as ligands for the extracellular receptor of a two-component signaling module. In both cases, the signal activates a complex adaptation response involving many genes.
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Affiliation(s)
- Gholson J Lyon
- Laboratory of Synthetic Protein Chemistry, The Rockefeller University, 1230 York Avenue, New York, NY 10021, USA
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214
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Qi F, Merritt J, Lux R, Shi W. Inactivation of the ciaH Gene in Streptococcus mutans diminishes mutacin production and competence development, alters sucrose-dependent biofilm formation, and reduces stress tolerance. Infect Immun 2004; 72:4895-9. [PMID: 15271957 PMCID: PMC470703 DOI: 10.1128/iai.72.8.4895-4899.2004] [Citation(s) in RCA: 99] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Many clinical isolates of Streptococcus mutans produce peptide antibiotics called mutacins. Mutacin production may play an important role in the ecology of S. mutans in dental plaque. In this study, inactivation of a histidine kinase gene, ciaH, abolished mutacin production. Surprisingly, the same mutation also diminished competence development, stress tolerance, and sucrose-dependent biofilm formation.
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Affiliation(s)
- Fengxia Qi
- Department of Oral Biology and Molecualr Biology Institute, UCLA School of Dentistry, P.O. Box 951668, Los Angeles, CA 90095-1668, USA.
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215
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Hoffmann A, Schneider T, Pag U, Sahl HG. Localization and functional analysis of PepI, the immunity peptide of Pep5-producing Staphylococcus epidermidis strain 5. Appl Environ Microbiol 2004; 70:3263-71. [PMID: 15184120 PMCID: PMC427782 DOI: 10.1128/aem.70.6.3263-3271.2004] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Pep5 is a cationic pore-forming lantibiotic produced by Staphylococcus epidermidis strain 5. The producer strain protects itself from the lethal action of its own bacteriocin through the 69-amino-acid immunity peptide PepI. The N-terminal segment of PepI contains a 20-amino-acid stretch of apolar residues, whereas the C terminus is very hydrophilic, with a net positive charge. We used green fluorescent protein (GFP)-PepI fusions to obtain information on its localization in vivo. PepI was found to occur outside the cytoplasm and to accumulate at the membrane-cell wall interface. The extracellular localization appeared essential for conferring immunity. We analyzed the functional role of the specific segments by constructing various mutant peptides, which were also fused to GFP. When the hydrophobic N-terminal segment of PepI was disrupted by introducing charged amino acids, the export of PepI was blocked and clones expressing such mutant peptides were Pep5 sensitive. When PepI was successively shortened at the C terminus, in contrast, its export properties remained unchanged whereas its ability to confer immunity was gradually reduced. The results show that the N-terminal part is required for the transport of PepI and that the C-terminal part is important for conferring the immunity phenotype. A concept based on target shielding is proposed for the PepI immunity mechanism.
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Affiliation(s)
- Anja Hoffmann
- Institut für Medizinische Mikrobiologie und Immunologie, Universität Bonn, D-53105 Bonn, Germany
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216
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Shankar N, Coburn P, Pillar C, Haas W, Gilmore M. Enterococcal cytolysin: activities and association with other virulence traits in a pathogenicity island. Int J Med Microbiol 2004; 293:609-18. [PMID: 15149038 DOI: 10.1078/1438-4221-00301] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Enterococcal cytolysin is a structurally novel bacterial toxin expressed by some strains of E. faecalis and is distantly related to the class of bacteriocins known as lantibiotics. The cytolysin can be encoded by large pheromone-responsive plasmids, or on the chromosome within pathogenicity island. It is produced by a complex process that involves the products of eight genes, designated cylR1, cylR2, cylLL, cylLS, cylM, cylB, cylA, and cylI. The cytolysin toxin, maturation and regulatory genes are organized into two divergent transcripts: a structural transcript cylLLLSMBAI, and a regulatory transcript cylR1R2. The active cytolysin subunits, CylLL" and CylLS", are synthesized ribosomally as non-identical peptides, post-translationally modified, then secreted and activated. The cytolysin operon is repressed by the activities of two proteins, CylR1 and CylR2, and derepressed by a quorum-sensing process involving secreted autoinducer CylLS". The cytolysin operon within the E. faecalis pathogenicity island is associated with other virulence determinants, including aggregation substance and enterococcal surface protein, Esp.
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Affiliation(s)
- Nathan Shankar
- College of Pharmacy, University of Oklahoma Health Sciences Center, Oklahoma City, OK 73190, USA
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217
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Kodani S, Hudson ME, Durrant MC, Buttner MJ, Nodwell JR, Willey JM. The SapB morphogen is a lantibiotic-like peptide derived from the product of the developmental gene ramS in Streptomyces coelicolor. Proc Natl Acad Sci U S A 2004; 101:11448-53. [PMID: 15277670 PMCID: PMC509221 DOI: 10.1073/pnas.0404220101] [Citation(s) in RCA: 210] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
SapB is a morphogenetic peptide that is important for aerial mycelium formation by the filamentous bacterium Streptomyces coelicolor. Production of SapB commences during aerial mycelium formation and depends on most of the genes known to be required for the morphogenesis of aerial hyphae. Furthermore, the application of purified SapB to mutants blocked in morphogenesis restores their capacity to form aerial hyphae. Here, we present evidence that SapB is a lantibiotic-like peptide that is derived by posttranslational modification from the product of a gene (ramS) in the four-gene ram operon, which is under the control of the regulatory gene ramR. We show that the product of another gene in the operon (ramC) contains a region that is similar to enzymes involved in the biosynthesis of lantibiotics, suggesting that it might be involved in the posttranslational processing of RamS. We conclude that SapB is derived from RamS through proteolytic cleavage and the introduction of four dehydroalanine residues and two lanthionine bridges. We provide an example of a morphogenetic role for an antibiotic-like molecule.
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Affiliation(s)
- Shinya Kodani
- Department of Biology, Hofstra University, Hempstead, NY 11549, USA
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218
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Papagianni M. Ribosomally synthesized peptides with antimicrobial properties: biosynthesis, structure, function, and applications. Biotechnol Adv 2004; 21:465-99. [PMID: 14499150 DOI: 10.1016/s0734-9750(03)00077-6] [Citation(s) in RCA: 173] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Ribosomally synthesized peptides with antimicrobial properties (antimicrobial peptides-AMPs) are produced by eukaryotes and prokaryotes and represent crucial components of their defense systems against microorganisms. Although they differ in structure, they are nearly all cationic and very often amphiphilic, which reflects the fact that many of them attack their target cells by permeabilizing the cell membrane. They can be roughly categorized into those that have a high content of a certain amino acid, most often proline, those that contain intramolecular disulfide bridges, and those with an amphiphilic region in their molecule if they assume an alpha-helical structure. Most of the known ribosomally synthesized peptides with antimicrobial functions have been identified and studied during the last 20 years. As a result of these studies, new knowledge has been acquired into biology and biochemistry. It has become evident that these peptides may be developed into useful antimicrobial additives and drugs. The use of two-peptide antimicrobial peptides as replacement for clinical antibiotics is promising, though their applications in preservation of foods (safe and effective for use in meat, vegetables, and dairy products), in veterinary medicine, and in dentistry are more immediate. This review focuses on the current status of some of the main types of ribosomally synthesized AMPs produced by eucaryotes and procaryotes and discusses the novel antimicrobial functions, new developments, e.g. heterologous production of bacteriocins by lactic acid bacteria, or construction of multibacteriocinogenic strains, novel applications related to these peptides, and future research paradigms.
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Affiliation(s)
- Maria Papagianni
- Department of Hygiene and Technology of Food of Animal Origin, School of Veterinary Medicine, Aristotle University of Thessaloniki, Thessaloniki 54006, Greece.
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219
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Were LM, Bruce B, Davidson PM, Weiss J. Encapsulation of nisin and lysozyme in liposomes enhances efficacy against Listeria monocytogenes. J Food Prot 2004; 67:922-7. [PMID: 15151228 DOI: 10.4315/0362-028x-67.5.922] [Citation(s) in RCA: 98] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
The efficacy and stability against Listeria monocytogenes of nisin and lysozyme encapsulated in phospholipid liposomes was evaluated. Antimicrobial-containing liposomes were prepared by hydrating dried lipids with buffer containing nisin, nisin plus the fluorescence probe calcein, or calcein and lysozyme. Mixtures were then centrifuged and sonicated, and encapsulated liposomes were collected using size-exclusion chromatography. Antimicrobial concentration in liposomes was determined by bicinchoninic acid assay prior to determination of antimicrobial activity against strains of L. monocytogenes. When nisin was encapsulated in liposomes, protein concentrations of 0.39, 0.27, and 0.23 mg/ml for phosphatidylcholine (PC), PC-cholesterol (7:3), and PC-phosphatidylglycerol (PG)-cholesterol (5:2:3), respectively, were obtained. Encapsulation of nisin with calcein yielded protein concentrations of 0.35, 0.39, and 0.28 mg/ml for PC, PC-cholesterol, and PC-PG-cholesterol, respectively. Encapsulation of calcein with lysozyme resulted in protein concentrations of 0.43, 0.26, and 0.19 mg/ml for PC, PC-cholesterol, and PC-PG-cholesterol, respectively. Encapsulated nisin in 100% PC and PC-cholesterol liposomes inhibited bacterial growth by >2 log CFU/ml compared with free nisin. Growth inhibition with liposomal lysozyme was strain dependent, with greater inhibition observed for strains 310 and Scott A with PC-cholesterol and PC-PG-cholesterol liposomes. Inhibition of L. monocytogenes indicated the potential of liposomes to serve as delivery vehicles for antimicrobials in foods while improving stability of antimicrobials.
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Affiliation(s)
- Lilian M Were
- Department of Physical Science, Chapman University, Orange, California 92866, USA
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220
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Zhou H, Schmidt DMZ, Gerlt JA, van der Donk WA. Chemical and enzymatic synthesis of fluorinated-dehydroalanine-containing peptides. Chembiochem 2004; 4:1206-15. [PMID: 14613113 DOI: 10.1002/cbic.200300654] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Michael acceptors have long been recognized as reactive functionalities that may link a biologically active molecule to its cellular target. 1,2-Dehydro amino acids are potential Michael acceptors present in a large number of natural products, but their reactivity is modulated by the deactivating nature of the alpha-amino group engaged in an amide bond. We describe here the preparation of 3-fluoro-1,2-dehydroalanine moieties within peptides that significantly enhance the reactivity of the Michael acceptor. Two different routes were designed to access these compounds, one relying on chemical means to introduce the desired functionality and the second taking advantage of a peptide epimerase. In the chemical approach, the fluoro-Pummerer reaction of cysteine derivatives afforded 3-fluorocysteine residues that were oxidized to the corresponding sulfoxides, followed by thermolytic elimination to provide the desired 3-fluorodehydroalanines. The mechanism of the fluoro-Pummerer reaction was investigated and several possible pathways were ruled out. The enzymatic approach utilized the dipeptide epimerase YcjG from Escherichia coli. Difluorinated alanine was incorporated at the C terminus of a dipeptide by chemical means. The resulting peptide proved to be a substrate for YcjG, which catalyzed fluoride elimination to provide the 3-fluorodehydroalanine-containing peptide. Mechanistic investigations showed that fluoride elimination occurred faster than epimerization and at a rate close to that of epimerization of Ala-Ala.
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Affiliation(s)
- Hao Zhou
- Department of Chemistry, University of Illinois at Urbana-Champaign, 600 South Mathews Avenue, Urbana, IL 61801, USA
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221
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Xie L, Miller LM, Chatterjee C, Averin O, Kelleher NL, van der Donk WA. Lacticin 481: In Vitro Reconstitution of Lantibiotic Synthetase Activity. Science 2004; 303:679-81. [PMID: 14752162 DOI: 10.1126/science.1092600] [Citation(s) in RCA: 197] [Impact Index Per Article: 9.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
The lantibiotic lacticin 481 is synthesized on ribosomes as a prepeptide (LctA) and posttranslationally modified to its mature form. These modifications include dehydration of serines and threonines, followed by intramolecular addition of cysteines to the unsaturated amino acids, which generates cyclic thioethers. This process breaks eight chemical bonds and forms six newbonds and is catalyzed by one enzyme, LctM. We have characterized the in vitro activity of LctM, which completely processed a series of LctA mutants, displaying a permissive substrate specificity that holds promise for antibiotic engineering.
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Affiliation(s)
- Lili Xie
- Department of Chemistry, University of Illinois at Urbana-Champaign, 600 S. Mathews Avenue, Urbana, IL61801, USA
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Zhang R, Zhang CT. Identification of genomic islands in the genome ofBacillus cereusby comparative analysis withBacillus anthracis. Physiol Genomics 2003; 16:19-23. [PMID: 14600214 DOI: 10.1152/physiolgenomics.00170.2003] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Horizontal gene transfer has been recognized as a universal event throughout bacterial evolution. The availability of both complete genome sequences of Bacillus cereus and B. anthracis provides the possibility to perform comparative analysis based on their genomes. By using a windowless method to display the distribution of the genomic GC content of B. cereus and B. anthracis, we have found three genomic islands in the genome of B. cereus, i.e., BCGI-1, BCGI-2, and BCGI-3, respectively, which are absent in the genome of B. anthracis. All the genomic islands have abrupt changes in GC content compared with that of surrounding regions. BCGI-1 has many conserved features of genomic islands, e.g., a Val-tRNA gene is utilized as the integration site, and a site-specific recombinase gene is located at the 3′ end. BCGI-2 has a large percentage of phage protein, suggesting a phage-related recombination is involved. BCGI-3 contains a ferric anguibactin transport system, which is likely to be involved in the iron transport that enables the bacterium to overcome the iron limitation in the host. In addition, BCGI-3 also contains a cluster of genes related to lantibiotics, which may play a role during the evolution of the genome. Furthermore, the integrations of the genomic islands, BCGI-1 and BCGI-3, result in deletions of DNA sequence fragments; therefore, such integrations lead to both gene gain and gene loss simultaneously.
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Affiliation(s)
- Ren Zhang
- Department of Epidemiology and Biostatistics, Tianjin Cancer Institute and Hospital, Tianjin 300060, China
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223
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References. Antibiotics (Basel) 2003. [DOI: 10.1128/9781555817886.refs] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
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Coburn PS, Gilmore MS. The Enterococcus faecalis cytolysin: a novel toxin active against eukaryotic and prokaryotic cells. Cell Microbiol 2003; 5:661-9. [PMID: 12969372 DOI: 10.1046/j.1462-5822.2003.00310.x] [Citation(s) in RCA: 109] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
The enterococcal cytolysin, a two-peptide lytic system, is a divergent relative of a large family of toxins and bacteriocins secreted by pathogenic and non-pathogenic Gram-positive bacteria. This family includes the lantibiotics and streptolysin S. The enterococcal cytolysin is of interest because its activities enhance enterococcal virulence in infection models and, in epidemiological studies, it has been associated with patient mortality. The cytolysin is lethal for a broad range of prokaryotic and eukaryotic cells, and this activity requires two non-identical, post-translationally modified peptides. The smaller of the two peptides also plays a role in a quorum-sensing autoinduction of the cytolysin operon. As a trait that is present in particularly virulent strains of Enterococcus faecalis, including strains that are resistant to multiple antibiotics, it serves as a model for testing the value of developing new virulence-targeting therapeutics. Further, because of the interest in small membrane active peptides as therapeutics themselves, studies of the molecular structure/activity relationships for the cytolysin peptides are providing insights into the physical basis for prokaryotic versus eukaryotic cell targeting.
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Affiliation(s)
- Phillip S Coburn
- Department of Microbiology and Immunology, Stanton L. Young Biomedical Research Center, Rm 356, The University of Oklahoma Health Sciences Center, PO Box 26901, Oklahoma City, OK 73190, USA
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Yamamoto Y, Togawa Y, Shimosaka M, Okazaki M. Purification and Characterization of a Novel Bacteriocin Produced by
Enterococcus faecalis
Strain RJ-11. Appl Environ Microbiol 2003; 69:5746-53. [PMID: 14532021 PMCID: PMC201181 DOI: 10.1128/aem.69.10.5546-5553.2003] [Citation(s) in RCA: 76] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
ABSTRACT
Lactic acid bacteria exhibiting activity against the gram-positive bacterium
Bacillus subtilis
were isolated from rice bran. One of the isolates, identified as
Enterococcus faecalis
RJ-11, exhibited a wide spectrum of growth inhibition with various gram-positive bacteria. A bacteriocin purified from culture fluid, designated enterocin RJ-11, was heat stable and was not sensitive to acid and alkaline conditions, but it was sensitive to several proteolytic enzymes. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis analysis revealed that enterocin RJ-11 had a molecular weight of 5,000 in its monomeric form. The amino acid sequence determined for purified enterocin RJ-11 exhibited high levels of similarity to the sequences of enterocins produced by
Enterococcus faecium
.
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Affiliation(s)
- Yukio Yamamoto
- Department of Applied Biology, Faculty of Textile Science and Technology, Shinshu University, Ueda, Nagano 386-8567, Japan
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226
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Fontaine MC, Lee JJ, Kehoe MA. Combined contributions of streptolysin O and streptolysin S to virulence of serotype M5 Streptococcus pyogenes strain Manfredo. Infect Immun 2003; 71:3857-65. [PMID: 12819070 PMCID: PMC162000 DOI: 10.1128/iai.71.7.3857-3865.2003] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Streptolysin O (SLO) and streptolysin S (SLS) are potent cytolytic toxins produced by almost all clinical isolates of group A streptococci (GAS). Allele-replacement mutagenesis was used to construct nonpolar (in-frame) deletion mutations in the slo and sagB genes of the serotype M5 GAS strain Manfredo, producing isogenic single and double SLO- and SLS-defective mutants. In contrast to recent reports on SLS-defective insertion mutants (I. Biswas, P. Germon, K. McDade, and J. Scott, Infect. Immun. 69:7029-7038, 2001; Z. Li, D. Sledjeski, B. Kreikemeyer, A.Podbielski, and M. Boyle, J. Bacteriol. 181:6019-6027, 1999), none of the mutants described here had notable pleiotropic effects on the expression of other virulence factors examined. Comparison of isogenic parent and mutant strains in various virulence models revealed no differences in their abilities to multiply in human blood or in their 50% lethal doses (LD(50)s) upon intraperitoneal infection of BALB/c mice. A single log unit difference in the LD(50)s of the parent and SLS-defective mutant strains was observed upon infection by the subcutaneous (s.c.) route. Comparisons over a range of infective doses showed that both SLO and SLS contributed to the early stages of infection and to the induction of necrotic lesions in the murine s.c. model. Individually, each toxin made an incremental contribution to virulence that was not apparent at higher infective doses, although the absence of both toxins reduced virulence over the entire dose range examined. Interestingly, in some cases, the contribution of SLO to virulence was clear only from an analysis of the double-mutant strain, highlighting the value of not confining virulence studies to mutant strains defective in the expression of only single virulence factors.
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Affiliation(s)
- Michael C Fontaine
- School of Cell and Molecular Biosciences, The Medical School, University of Newcastle upon Tyne, Newcastle upon Tyne NE2 4HH, United Kingdom
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227
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Szekat C, Jack RW, Skutlarek D, Färber H, Bierbaum G. Construction of an expression system for site-directed mutagenesis of the lantibiotic mersacidin. Appl Environ Microbiol 2003; 69:3777-83. [PMID: 12839744 PMCID: PMC165212 DOI: 10.1128/aem.69.7.3777-3783.2003] [Citation(s) in RCA: 68] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The lantibiotic (i.e., lanthionine-containing antibiotic) mersacidin is an antimicrobial peptide of 20 amino acids which is produced by Bacillus sp. strain HIL Y-85,54728. Mersacidin inhibits bacterial cell wall biosynthesis by binding to the precursor molecule lipid II. The structural gene of mersacidin (mrsA) and the genes for the enzymes of the biosynthesis pathway, dedicated transporters, producer self-protection proteins, and regulatory factors are organized in a biosynthetic gene cluster. For site-directed mutagenesis of lantibiotics, the engineered genes must be expressed in an expression system that contains all of the factors necessary for biosynthesis, export, and producer self-protection. In order to express engineered mersacidin peptides, a system in which the engineered gene replaces the wild-type gene on the chromosome was constructed. To test the expression system, three mutants were constructed. In S16I mersacidin, the didehydroalanine residue (Dha) at position 16 was replaced with the Ile residue found in the closely related lantibiotic actagardine. S16I mersacidin was produced only in small amounts. The purified peptide had markedly reduced antimicrobial activity, indicating an essential role for Dha16 in biosynthesis and biological activity of mersacidin. Similarly, Glu17, which is thought to be an essential structure in mersacidin, was exchanged for alanine. E17A mersacidin was obtained in good yields but also showed markedly reduced activity, thus confirming the importance of the carboxylic acid function at position 17 in the biological activity of mersacidin. Finally, the exchange of an aromatic for an aliphatic hydrophobic residue at position 3 resulted in the mutant peptide F3L mersacidin; this peptide showed only moderately reduced activity.
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Affiliation(s)
- Christiane Szekat
- Institut für Medizinische Mikrobiologie und Immunologie der Universität Bonn, Sigmund-Freud-Strasse 25, D-53105 Bonn, Germany
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229
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McCafferty DG, Cudic P, Frankel BA, Barkallah S, Kruger RG, Li W. Chemistry and biology of the ramoplanin family of peptide antibiotics. Biopolymers 2003; 66:261-84. [PMID: 12491539 DOI: 10.1002/bip.10296] [Citation(s) in RCA: 86] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
The peptide antibiotic ramoplanin factor A2 is a promising clinical candidate for treatment of Gram-positive bacterial infections that are resistant to antibiotics such as glycopeptides, macrolides, and penicillins. Since its discovery in 1984, no clinical or laboratory-generated resistance to this antibiotic has been reported. The mechanism of action of ramoplanin involves sequestration of peptidoglycan biosynthesis Lipid intermediates, thus physically occluding these substrates from proper utilization by the late-stage peptidoglycan biosynthesis enzymes MurG and the transglycosylases (TGases). Ramoplanin is structurally related to two cell wall active lipodepsipeptide antibiotics, janiemycin, and enduracidin, and is functionally related to members of the lantibiotic class of antimicrobial peptides (mersacidin, actagardine, nisin, and epidermin) and glycopeptide antibiotics (vancomycin and teicoplanin). Peptidomimetic chemotherapeutics derived from the ramoplanin sequence may find future use as antibiotics against vancomycin-resistant Enterococcus faecium (VRE), methicillin-resistant Staphylococcus aureus (MRSA), and related pathogens. Here we review the chemistry and biology of the ramoplanins including its discovery, structure elucidation, biosynthesis, antimicrobial activity, mechanism of action, and total synthesis.
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Affiliation(s)
- Dewey G McCafferty
- Department of Biochemistry and Biophysics and the Johnson Research Foundation, The University of Pennsylvania School of Medicine, Philadelphia 19104-6059, USA.
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230
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Puertollano MA, Gaforio JJ, Gálvez A, de Pablo MA, Alvarez de Cienfuegos G. Analysis of pro-inflammatory cytokine production in mouse spleen cells in response to the lantibiotic nisin. Int J Antimicrob Agents 2003; 21:601-3. [PMID: 12791482 DOI: 10.1016/s0924-8579(03)00088-8] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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231
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Korobov VP, Lemkina LM, Polyudova TV. Production of a wide-spectrum antibacterial factor by Staphylococcus warneri cells. DOKLADY BIOLOGICAL SCIENCES : PROCEEDINGS OF THE ACADEMY OF SCIENCES OF THE USSR, BIOLOGICAL SCIENCES SECTIONS 2003; 390:286-8. [PMID: 12940166 DOI: 10.1023/a:1024438407620] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Affiliation(s)
- V P Korobov
- Institute of Ecology and Genetics of Microorganisms, Ural Division, Russian Academy of Sciences, ul. Goleva 13, Perm, 614081 Russia
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232
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Corvey C, Stein T, Düsterhus S, Karas M, Entian KD. Activation of subtilin precursors by Bacillus subtilis extracellular serine proteases subtilisin (AprE), WprA, and Vpr. Biochem Biophys Res Commun 2003; 304:48-54. [PMID: 12705882 DOI: 10.1016/s0006-291x(03)00529-1] [Citation(s) in RCA: 81] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
The maturation of the peptide antibiotic (lantibiotic) subtilin in Bacillus subtilis ATCC 6633 includes posttranslational modifications of the propeptide and proteolytic cleavage of the leader peptide. To identify subtilin processing activities, we used antimicrobial inactive subtilin precursors consisting of the leader peptide which was still attached to the fully matured propeptide. Two extracellular B. subtilis proteases were able to activate subtilin precursors, the commercially available serine protease prototype subtilisin (AprE) and WprA. The latter was isolated from B. subtilis WB600, a strain deficient in six extracellular proteases. Surprisingly, the aprE wprA double mutant of the ATCC 6633 strain was still able to produce active subtilin, however, with a reduced production rate. No subtilin processing was found within the culture supernatant of the WB800 strain, which is deficient in eight extracellular proteases. Vpr was identified as the third protease capable to process subtilin.
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Affiliation(s)
- Carsten Corvey
- Institut für Pharmazeutische Chemie, Johann Wolfgang Goethe-Universität, Marie-Curie-Str. 9-11, 60439, Frankfurt/M, Germany
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233
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Martin NI, Hu H, Moake MM, Churey JJ, Whittal R, Worobo RW, Vederas JC. Isolation, structural characterization, and properties of mattacin (polymyxin M), a cyclic peptide antibiotic produced by Paenibacillus kobensis M. J Biol Chem 2003; 278:13124-32. [PMID: 12569104 DOI: 10.1074/jbc.m212364200] [Citation(s) in RCA: 74] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Mattacin is a nonribosomally synthesized, decapeptide antibiotic produced by Paenibacillus kobensis M. The producing strain was isolated from a soil/manure sample and identified using 16 S rRNA sequence homology along with chemical and morphological characterization. An efficient production and isolation procedure was developed to afford pure mattacin. Structure elucidation using a combination of chemical degradation, multidimensional NMR studies (COSY, HMBC, HMQC, ROESY), and mass spectrometric (MALDI MS/MS) analyses showed that mattacin is identical to polymyxin M, an uncommon antibiotic reported previously in certain Bacillus species by Russian investigators. Mattacin (polymyxin M) is cyclic and possesses an amide linkage between the C-terminal threonine and the side chain amino group of the diaminobutyric acid residue at position 4. It contains an (S)-6-methyloctanoic acid moiety attached as an amide at the N-terminal amino group, one D-leucine, six L-alpha,gamma-diaminobutyric acid, and three L-threonine residues. Transfer NOE experiments on the conformational preferences of mattacin when bound to lipid A and microcalorimetry studies on binding to lipopolysaccharide showed that its behavior was very similar to that observed in previous studies of polymyxin B (a commercial antibiotic), suggesting an identical mechanism of action. It was capable of inhibiting the growth of a wide variety of Gram-positive and Gram-negative bacteria, including several human and plant pathogens with activity comparable with purified polymyxin B. The biosynthesis of mattacin was also examined briefly using transpositional mutagenesis by which 10 production mutants were obtained, revealing a set of genes involved in production.
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Affiliation(s)
- Nathaniel I Martin
- Department of Chemistry, University of Alberta, Edmonton, Alberta T6G 2G2, Canada
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234
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Widdick DA, Dodd HM, Barraille P, White J, Stein TH, Chater KF, Gasson MJ, Bibb MJ. Cloning and engineering of the cinnamycin biosynthetic gene cluster from Streptomyces cinnamoneus cinnamoneus DSM 40005. Proc Natl Acad Sci U S A 2003; 100:4316-21. [PMID: 12642677 PMCID: PMC153090 DOI: 10.1073/pnas.0230516100] [Citation(s) in RCA: 102] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Lantibiotics are ribosomally synthesized oligopeptide antibiotics that contain lanthionine bridges derived by the posttranslational modification of amino acid residues. Here, we describe the cinnamycin biosynthetic gene cluster (cin) from Streptomyces cinnamoneus cinnamoneus DSM 40005, the first, to our knowledge, lantibiotic gene cluster from a high G+C bacterium to be cloned and sequenced. The cin cluster contains many genes not found in lantibiotic clusters from low G+C Gram-positive bacteria, including a Streptomyces antibiotic regulatory protein regulatory gene, and lacks others found in such clusters, such as a LanT-type transporter and a LanP-type protease. Transfer of the cin cluster to Streptomyces lividans resulted in heterologous production of cinnamycin. Furthermore, modification of the cinnamycin structural gene (cinA) led to production of two naturally occurring lantibiotics, duramycin and duramycin B, closely resembling cinnamycin, whereas attempts to make a more widely diverged derivative, duramycin C, failed to generate biologically active material. These results provide a basis for future attempts to construct extensive libraries of cinnamycin variants.
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Affiliation(s)
- D A Widdick
- Department of Molecular Microbiology, John Innes Centre, Colney Lane, Norwich, Norfolk NR4 7UH, United Kingdom
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235
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Steinbacher S, Hernández-Acosta P, Bieseler B, Blaesse M, Huber R, Culiáñez-Macià FA, Kupke T. Crystal structure of the plant PPC decarboxylase AtHAL3a complexed with an ene-thiol reaction intermediate. J Mol Biol 2003; 327:193-202. [PMID: 12614618 DOI: 10.1016/s0022-2836(03)00092-5] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The Arabidopsis thaliana protein AtHAL3a decarboxylates 4'-phosphopantothenoylcysteine to 4'-phosphopantetheine, a step in coenzyme A biosynthesis. Surprisingly, this decarboxylation reaction is carried out as an FMN-dependent redox reaction. In the first half-reaction, the side-chain of the cysteine residue of 4'-phosphopantothenoylcysteine is oxidised and the thioaldehyde intermediate decarboxylates spontaneously to the 4'-phosphopantothenoyl-aminoethenethiol intermediate. In the second half-reaction this compound is reduced to 4'-phosphopantetheine and the FMNH(2) cofactor is re-oxidised. The active site mutant C175S is unable to perform this reductive half-reaction. Here, we present the crystal structure of the AtHAL3a mutant C175S in complex with the reaction intermediate pantothenoyl-aminoethenethiol and FMNH(2). The geometry of binding suggests that reduction of the C(alpha)=C(beta) double bond of the intermediate can be performed by direct hydride-transfer from N5 of FMNH(2) to C(beta) of the aminoethenethiol-moiety supported by a protonation of C(alpha) by Cys175. The binding mode of the substrate is very similar to that previously observed for a pentapeptide to the homologous enzyme EpiD that introduces the aminoethenethiol-moiety as final reaction product at the C terminus of peptidyl-cysteine residues. This finding further supports our view that these homologous enzymes form a protein family of homo-oligomeric flavin-containing cysteine decarboxylases, which we have termed HFCD family.
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Affiliation(s)
- Stefan Steinbacher
- Max-Planck-Institut für Biochemie, Abteilung für Strukturforschung, Am Klopferspitz 18a, D-82152 Martinsried, Germany.
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Stein T, Heinzmann S, Kiesau P, Himmel B, Entian KD. The spa-box for transcriptional activation of subtilin biosynthesis and immunity in Bacillus subtilis. Mol Microbiol 2003; 47:1627-36. [PMID: 12622817 DOI: 10.1046/j.1365-2958.2003.03374.x] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
The subtilin gene cluster (spa) of Bacillus subtilis ATCC 6633 is organized in transcriptional units spaBTC, spaS, spaIFEG and spaRK. Specific binding of the response regulator protein SpaR to spaB, spaS and spaI DNA promoter fragments was shown by means of electromobility shift assays. A repeated pentanucleotide sequence spaced by six nucleotides was identified as SpaR binding motif (spa-box). Saturating mutational analysis of the spa-box by single- and multiple-base-pair substitutions revealed the consensus motif (A/T)TGAT for optimal SpaR binding with the second, third and fifth position being absolutely conservative. Variations in the spacer size between the two pentanucleotide repeats revealed a strong conservation of their relative location. Only DNA with a proximal arrangement of two pentanucleotide repeats showed affinity to SpaR. A 2:1 stoichiometry between SpaR and DNA was obtained by optical biosensor analyses, which corresponds to the binding of two SpaR proteins per spa-box.
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Affiliation(s)
- Torsten Stein
- Institut für Mikrobiologie, Johann Wolfgang Goethe-Universität, Marie-Curie-Str. 9, 60439 Frankfurt am Main, Germany
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237
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Kemperman R, Kuipers A, Karsens H, Nauta A, Kuipers O, Kok J. Identification and characterization of two novel clostridial bacteriocins, circularin A and closticin 574. Appl Environ Microbiol 2003; 69:1589-97. [PMID: 12620847 PMCID: PMC150056 DOI: 10.1128/aem.69.3.1589-1597.2003] [Citation(s) in RCA: 100] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Two novel antibacterial peptides of clostridial species were purified, N-terminally sequenced, and characterized. Moreover, their structural genes were identified. Closticin 574 is an 82-amino-acid bacteriocin produced by Clostridium tyrobutyricum ADRIAT 932. The supernatant of the producing strain showed a high level of activity against the indicator strain C. tyrobutyricum. The protein is synthesized as a preproprotein that is possibly secreted via the general secretion pathway, after which it is hydrolyzed at an Asp-Pro site. Circularin A is produced by Clostridium beijerinckii ATCC 25752 as a prepeptide of 72 amino acids. Cleavage of the prepeptide between the third leucine and fourth valine residues followed by a head-to-tail ligation between the N and C termini creates a circular antimicrobial peptide of 69 amino acids. The unusually small circularin A leader peptide of three amino acids is cleaved off in this process. The supernatant of C. beijerinckii ATCC 25752 showed a broad antibacterial activity range.
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Affiliation(s)
- Robèr Kemperman
- Department of Molecular Genetics, Biomolecular Sciences and Biotechnology Institute, University of Groningen, Groningen, The Netherlands
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238
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Stein T, Heinzmann S, Solovieva I, Entian KD. Function of Lactococcus lactis nisin immunity genes nisI and nisFEG after coordinated expression in the surrogate host Bacillus subtilis. J Biol Chem 2003; 278:89-94. [PMID: 12379654 DOI: 10.1074/jbc.m207237200] [Citation(s) in RCA: 133] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Nisin-producing Lactococcus lactis strains show a high degree of resistance to the action of nisin, which is based upon expression of the self-protection (immunity) genes nisI, nisF, nisE, and nisG. Different combinations of nisin immunity genes were integrated into the chromosome of a nisin-sensitive Bacillus subtilis host strain under the control of an inducible promoter. For the recipient strain, the highest level of acquired nisin tolerance was achieved after coordinated expression of all four nisin immunity genes. But either the lipoprotein NisI or the ABC transporter-homologous system NisFEG, respectively, were also able to protect the Bacillus host cells. The acquired immunity was specific to nisin and provided no tolerance to subtilin, a closely related lantibiotic. Quantitative in vivo peptide release assays demonstrated that NisFEG diminished the quantity of cell-associated nisin, providing evidence that one role of NisFEG is to transport nisin from the membrane into the extracellular space. NisI solubilized from B. subtilis membrane vesicles and recombinant hexahistidine-tagged NisI from Escherichia coli interacted specifically with nisin and not with subtilin. This suggests a function of NisI as a nisin-intercepting protein.
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Affiliation(s)
- Torsten Stein
- Institut für Mikrobiologie, Johann Wolfgang Goethe-Universität, D-60439 Frankfurt am Main, Germany
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239
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Guiotto A, Pozzobon M, Canevari M, Manganelli R, Scarin M, Veronese FM. PEGylation of the antimicrobial peptide nisin A: problems and perspectives. FARMACO (SOCIETA CHIMICA ITALIANA : 1989) 2003; 58:45-50. [PMID: 12595036 DOI: 10.1016/s0014-827x(02)01301-0] [Citation(s) in RCA: 54] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
Nisin is a natural antimicrobial peptide produced by Lactococcus lactis and widely employed as food preservative. Its low solubility in neutral aqueous solutions, its instability at physiological pH and its rapid breakdown by proteolytic enzymes has limited its use for processed foods (processed cheese, milk and derivatives, canned vegetables). The conjugation to poly(ethylene glycol) (PEG) could improve its solubility and protect it towards enzymes present in non optimally processed food. We report the synthesis of a PEG-nisin conjugate, and the microbiology assays against some bacterial cell lines.
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240
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Georgalaki MD, Van Den Berghe E, Kritikos D, Devreese B, Van Beeumen J, Kalantzopoulos G, De Vuyst L, Tsakalidou E. Macedocin, a food-grade lantibiotic produced by Streptococcus macedonicus ACA-DC 198. Appl Environ Microbiol 2002; 68:5891-903. [PMID: 12450808 PMCID: PMC134371 DOI: 10.1128/aem.68.12.5891-5903.2002] [Citation(s) in RCA: 81] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2002] [Accepted: 08/21/2002] [Indexed: 11/20/2022] Open
Abstract
Streptococcus macedonicus ACA-DC 198, a strain isolated from Greek Kasseri cheese, produces a food-grade lantibiotic named macedocin. Macedocin has a molecular mass of 2,794.76 +/- 0.42 Da, as determined by electrospray mass spectrometry. Partial N-terminal sequence analysis revealed 22 amino acid residues that correspond with the amino acid sequence of the lantibiotics SA-FF22 and SA-M49, both of which were isolated from the pathogen Streptococcus pyogenes. Macedocin inhibits a broad spectrum of lactic acid bacteria, as well as several food spoilage and pathogenic bacteria, including Clostridium tyrobutyricum. It displays a bactericidal effect towards the most sensitive indicator strain, Lactobacillus sakei subsp. sakei LMG 13558(T), while the producer strain itself displays autoinhibition when it is grown under conditions that do not favor bacteriocin production. Macedocin is active at pHs between 4.0 and 9.0, and it retains activity even after incubation for 20 min at 121 degrees C with 1 atm of overpressure. Inhibition of macedocin by proteolytic enzymes is variable.
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Affiliation(s)
- Marina D Georgalaki
- Laboratory of Dairy Research, Department of Food Science and Technology, Agricultural University of Athens, Greece
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241
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Abstract
A zone of beta-hemolysis surrounding colonies on blood-agar media is a hallmark phenotypic feature of the pathogens group A Streptococcus (GAS) and group B Streptococcus (GBS). In each case, lysis of red blood cells reflects the action of a potent protein exotoxin. Although these toxins have been the subjects of numerous investigations over the years, their purification and molecular identification have proven elusive. These difficulties reflect the instability of hemolytic activity, as both toxins function only in the context of the bacterial surface or certain high molecular weight 'stabilizer' molecules. This review highlights the recent discoveries of two markedly distinct genetic loci, necessary and sufficient for the beta-hemolytic phenotypes of GAS and GBS, respectively. The generation of isogenic GAS and GBS beta-hemolysin-deficient mutants and their analysis using in vitro and in vivo model systems has shown that both toxins function as virulence factors in the pathogenesis of invasive infections.
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Affiliation(s)
- Victor Nizet
- Division of Pediatric Infectious Diseases, University of California, San Diego, 9500 Gilman Drive, MC 0672, La Jolla 92093, USA.
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242
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Abstract
Preservation of food and beverages resulting from fermentation has been an effective form of extending the shelf-life of foods for millennia. Traditionally, foods were preserved through naturally occurring fermentations, however, modern large scale production generally now exploits the use of defined strain starter systems to ensure consistency and quality in the final product. This review will mainly focus on the use of lactic acid bacteria (LAB) for food improvement, given their extensive application in a wide range of fermented foods. These microorganisms can produce a wide variety of antagonistic primary and secondary metabolites including organic acids, diacetyl, CO2 and even antibiotics such as reuterocyclin produced by Lactobacillus reuteri. In addition, members of the group can also produce a wide range of bacteriocins, some of which have activity against food pathogens such as Listeria monocytogenes and Clostridium botulinum. Indeed, the bacteriocin nisin has been used as an effective biopreservative in some dairy products for decades, while a number of more recently discovered bacteriocins, such as lacticin 3147, demonstrate increasing potential in a number of food applications. Both of these lactococcal bacteriocins belong to the lantibiotic family of posttranslationally modified bacteriocins that contain lanthionine, beta-methyllanthionine and dehydrated amino acids. The exploitation of such naturally produced antagonists holds tremendous potential for extension of shelf-life and improvement of safety of a variety of foods.
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243
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Netz DJA, Bastos MDCDF, Sahl HG. Mode of action of the antimicrobial peptide aureocin A53 from Staphylococcus aureus. Appl Environ Microbiol 2002; 68:5274-80. [PMID: 12406714 PMCID: PMC129900 DOI: 10.1128/aem.68.11.5274-5280.2002] [Citation(s) in RCA: 48] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
We investigated the mode of action of aureocin A53 on living bacterial cells and model membranes. Aureocin A53 acted bactericidally against Staphylococcus simulans 22, with >90% of the cells killed within a few minutes. Cell death was followed by lysis, as indicated by a clearing of the cell suspension and Gram staining. Aureocin A53 rapidly dissipated the membrane potential and simultaneously stopped biosynthesis of DNA, polysaccharides, and protein. Aureocin A53 induced a rapid release of preaccumulated glutamate and Rb(+). Experiments on model membranes demonstrated that aureocin A53 provoked significant leakage of carboxyfluorescein (CF) exclusively from acidic liposomes but only at relatively high concentrations (0.5 to 8 mol%). Thus, the bactericidal activity of aureocin A53 derives from membrane permeation via generalized membrane destruction rather than by formation of discrete pores within membranes. Tryptophan emission fluorescence spectroscopy demonstrated interaction of aureocin A53 with both acidic and neutral membranes, as indicated by similar blue shifts. Since there was no significant aureocin A53-induced CF leakage from neutral liposomes, its appears that the peptide does interact with neutral lipids without provoking membrane damage.
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Affiliation(s)
- Daili Jacqueline Aguilar Netz
- Departamento de Microbiologia Geral, Instituto de Microbiologia, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil
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244
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Benech RO, Kheadr EE, Lacroix C, Fliss I. Antibacterial activities of nisin Z encapsulated in liposomes or produced in situ by mixed culture during cheddar cheese ripening. Appl Environ Microbiol 2002; 68:5607-19. [PMID: 12406756 PMCID: PMC129882 DOI: 10.1128/aem.68.11.5607-5619.2002] [Citation(s) in RCA: 89] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2002] [Accepted: 08/02/2002] [Indexed: 11/20/2022] Open
Abstract
This study investigated both the activity of nisin Z, either encapsulated in liposomes or produced in situ by a mixed starter, against Listeria innocua, Lactococcus spp., and Lactobacillus casei subsp. casei and the distribution of nisin Z in a Cheddar cheese matrix. Nisin Z molecules were visualized using gold-labeled anti-nisin Z monoclonal antibodies and transmission electron microscopy (immune-TEM). Experimental Cheddar cheeses were made using a nisinogenic mixed starter culture, containing Lactococcus lactis subsp. lactis biovar diacetylactis UL 719 as the nisin producer and two nisin-tolerant lactococcal strains and L. casei subsp. casei as secondary flora, and ripened at 7 degrees C for 6 months. In some trials, L. innocua was added to cheese milk at 10(5) to 10(6) CFU/ml. In 6-month-old cheeses, 90% of the initial activity of encapsulated nisin (280 +/- 14 IU/g) was recovered, in contrast to only 12% for initial nisin activity produced in situ by the nisinogenic starter (300 +/- 15 IU/g). During ripening, immune-TEM observations showed that encapsulated nisin was located mainly at the fat/casein interface and/or embedded in whey pockets while nisin produced by biovar diacetylactis UL 719 was uniformly distributed in the fresh cheese matrix but concentrated in the fat area as the cheeses aged. Cell membrane in lactococci appeared to be the main nisin target, while in L. casei subsp. casei and L. innocua, nisin was more commonly observed in the cytoplasm. Cell wall disruption and digestion and lysis vesicle formation were common observations among strains exposed to nisin. Immune-TEM observations suggest several modes of action for nisin Z, which may be genus and/or species specific and may include intracellular target-specific activity. It was concluded that nisin-containing liposomes can provide a powerful tool to improve nisin stability and availability in the cheese matrix.
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Affiliation(s)
- R-O Benech
- Dairy Research Centre STELA, Université Laval, Québec, PQ, Canada G1K 7P4
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245
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Abstract
Probiotic ingestion can be recommended as a preventative approach to maintaining the balance of the intestinal microflora and thereby enhance 'well-being'. Research into the use of probiotic intervention in specific illnesses and disorders has identified certain patient populations that may benefit from the approach. Undoubtedly, probiotics will vary in their efficacy and it may not be the case that the same results occur with all species. Those that prove most efficient will likely be strains that are robust enough to survive the harsh physico-chemical conditions present in the gastrointestinal tract. This includes gastric acid, bile secretions and competition with the resident microflora. A survey of the literature indicates positive results in over fifty human trials, with prevention/treatment of infections the most frequently reported output. In theory, increased levels of probiotics may induce a 'barrier' influence against common pathogens. Mechanisms of effect are likely to include the excretion of acids (lactate, acetate), competition for nutrients and gut receptor sites, immunomodulation and the formation of specific antimicrobial agents. As such, persons susceptible to diarrhoeal infections may benefit greatly from probiotic intake. On a more chronic basis, it has been suggested that some probiotics can help maintain remission in the inflammatory conditions, ulcerative colitis and pouchitis. They have also been suggested to repress enzymes responsible for genotoxin formation. Moreover, studies have suggested that probiotics are as effective as anti-spasmodic drugs in the alleviation of irritable bowel syndrome. The approach of modulating the gut flora for improved health has much relevance for the management of those with acute and chronic gut disorders. Other target groups could include those susceptible to nosocomial infections, as well as the elderly, who have an altered microflora, with a decreased number of beneficial microbial species. For the future, it is imperative that mechanistic interactions involved in probiotic supplementation be identified. Moreover, the survival issues associated with their establishment in the competitive gut ecosystem should be addressed. Here, the use of prebiotics in association with useful probiotics may be a worthwhile approach. A prebiotic is a dietary carbohydrate selectively metabolised by probiotics. Combinations of probiotics and prebiotics are known as synbiotics.
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Affiliation(s)
- L J Fooks
- Food Microbial Sciences Unit, School of Food Biosciences, The University of Reading, Whiteknights, RG6 6AP, UK
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246
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Hoffmann A, Pag U, Wiedemann I, Sahl HG. Combination of antibiotic mechanisms in lantibiotics. FARMACO (SOCIETA CHIMICA ITALIANA : 1989) 2002; 57:685-91. [PMID: 12361237 DOI: 10.1016/s0014-827x(02)01208-9] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
Recent studies on the mode of action have revealed exciting features of multiple activities of nisin and related lantibiotics making these peptides interesting model systems for the design of new antibiotics (Molec. Microbiol. 30 (1998) 317; Science 286 (1999) 2361; J. Biol. Chem. 276 (2001) 1772.). In contrast to other groups of antibiotic peptides, the lantibiotics display a substantial degree of specificity for particular components of bacterial membranes. Mersacidin and actagardine were shown to bind with high affinity to the lipid coupled peptidoglycan precursor, the so-called lipid II, which prevents the polymerisation of the cell wall monomers into a functional murein sacculus. The lantibiotics nisin and epidermin also bind tightly to this cell wall precursor; however, for these lantibiotics the binding of lipid II has two consequences. Like with mersacidin blocking of lipid II inhibits peptidoglycan biosynthesis; in addition, lipid II is used as a specific docking molecule for the formation of pores. This combination of lethal effects explains the potency of these peptides, which are active in nanomolar concentration. Other type-A lantibiotics are believed to also use docking molecules for pore formation, although identification of such membrane components has not yet been achieved.
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Affiliation(s)
- Anja Hoffmann
- Institut für Medizinische Mikrobiologie und Immunologie der Universität Bonn, Germany
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247
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Kawamoto S, Shima J, Sato R, Eguchi T, Ohmomo S, Shibato J, Horikoshi N, Takeshita K, Sameshima T. Biochemical and genetic characterization of mundticin KS, an antilisterial peptide produced by Enterococcus mundtii NFRI 7393. Appl Environ Microbiol 2002; 68:3830-40. [PMID: 12147478 PMCID: PMC124038 DOI: 10.1128/aem.68.8.3830-3840.2002] [Citation(s) in RCA: 89] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Mundticin KS, a bacteriocin produced by Enterococcus mundtii NFRI 7393 isolated from grass silage in Thailand, is active against closely related lactic acid bacteria and the food-borne pathogen Listeria monocytogenes. In this study, biochemical and genetic characterization of mundticin KS was done. Mundticin KS was purified to homogeneity by ammonium sulfate precipitation, sequential ion-exchange chromatography, and solid-phase extraction. The gene cluster (mun locus) for mundticin KS production was cloned, and DNA sequencing revealed that the mun locus consists of three genes, designated munA, munB, and munC. The munA gene encodes a 58-amino-acid mundticin KS precursor, munB encodes a protein of 674 amino acids involved in translocation and processing of the bacteriocin, and munC encodes a mundticin KS immunity protein of 98 amino acids. Amino acid and nucleotide sequencing revealed the complete, unambiguous primary structure of mundticin KS; mundticin KS comprises a 43-amino-acid peptide with an amino acid sequence similar to that of mundticin ATO6 produced by E. mundtii ATO6. Mundticin KS and mundticin ATO6 are distinguished by the inversion of the last two amino acids at their respective C termini. These two mundticins were expressed in Escherichia coli as recombinant peptides and found to be different in activity against certain Lactobacillus strains, such as Lactobacillus plantarum and Lactobacillus curvatus. Mundticin KS was successfully expressed by transformation with the recombinant plasmid containing the mun locus in heterogeneous hosts such as E. faecium, L. curvatus, and Lactococcus lactis. Based on our results, the mun locus is located on a 50-kb plasmid, pML1, of E. mundtii NFRI 7393.
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248
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Gomez A, Ladire M, Marcille F, Nardi M, Fons M. Characterization of ISRgn1, a novel insertion sequence of the IS3 family isolated from a bacteriocin-negative mutant of Ruminococcus gnavus E1. Appl Environ Microbiol 2002; 68:4136-9. [PMID: 12147521 PMCID: PMC124057 DOI: 10.1128/aem.68.8.4136-4139.2002] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
ISRgn1, an insertion sequence of the IS3 family, has been identified in the genome of a bacteriocin-negative mutant of Ruminococcus gnavus E1. The copy number of ISRgn1 in R. gnavus E1, as well as its distribution among phylogenetically E1-related strains, has been determined. Results obtained suggest that ISRgn1 is not indigenous to the R. gnavus phylogenetic group but that it can transpose in this bacterium.
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Affiliation(s)
- Ana Gomez
- Mixis France, Faculte de Medicine Necker-Enfants Malades, 75730 Paris Cedex 15, France.
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249
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Xie L, Chatterjee C, Balsara R, Okeley NM, van der Donk WA. Heterologous expression and purification of SpaB involved in subtilin biosynthesis. Biochem Biophys Res Commun 2002; 295:952-7. [PMID: 12127987 DOI: 10.1016/s0006-291x(02)00783-0] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Lantibiotic peptides contain thioether bridges termed lanthionines that are putatively generated by dehydration of Ser and Thr residues followed by Michael addition of cysteine residues within the peptide. The LanB and LanC proteins have been proposed to catalyze the dehydration and formation of the thioether rings, respectively. We report here the first heterologous overexpression in Escherichia coli of SpaB, the putative dehydratase for subtilin. Sequence analysis of spaB revealed several nucleotide differences with current gene database entries. The solubility of SpaB was increased dramatically when co-expressed with GroEL/ES, and soluble His(6)-tagged SpaB was purified. The protein is at least a dimer, and interaction between SpaB and SpaC was observed. SpaS the putative substrate for SpaB was overexpressed in E. coli as an intein fusion protein, and after cleavage, the peptide was obtained in good yield.
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Affiliation(s)
- Lili Xie
- Department of Chemistry, University of Illinois at Urbana-Champaign, 600 South Mathews Ave, Urbana, IL 61801, USA
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250
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Netz DJA, Pohl R, Beck-Sickinger AG, Selmer T, Pierik AJ, Bastos MDCDF, Sahl HG. Biochemical characterisation and genetic analysis of aureocin A53, a new, atypical bacteriocin from Staphylococcus aureus. J Mol Biol 2002; 319:745-56. [PMID: 12054867 DOI: 10.1016/s0022-2836(02)00368-6] [Citation(s) in RCA: 80] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
Aureocin A53 is produced by Staphylococcus aureus A53. It is encoded on a 10.4 kb plasmid, pRJ9, and is active against Listeria monocytogenes. Aureocin A53 is a highly cationic 51-residue peptide containing ten lysine and five tryptophan residues. Aureocin A53 was purified to homogeneity by hydrophobic-interaction, cation-exchange, and reverse-phase chromatography. MALDI-TOF mass spectrometry yielded a molecular mass of 6012.5 Da, which was 28 Da higher than predicted from the structural gene sequence of the bacteriocin. The mass increment resulted from an N-formylmethionine residue, indicating that the aureocin A53 is synthesised and secreted without a typical bacteriocin leader sequence or sec-dependent signal peptide. The structural identity of aureocin A53 was verified by Edman sequencing after de-blocking with cyanogen bromide and extensive mass spectrometry analysis of enzymatically and laser-generated fragments. The complete sequence of pRJ9 was determined and none of the open reading frames identified in the vicinity of the structural gene aucA showed similarity to genes that are typically found in bacteriocin gene clusters. Thus, neither a dedicated protease or transporter, nor modifying enzymes and regulatory elements seemed to be involved in the production of aureocin A53. Further unique features that distinguish aureocin A53 from other peptide bacteriocins include remarkable protease stability and a defined, rigid structure in aqueous solution.
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Affiliation(s)
- Daili Jacqueline Aguilar Netz
- Departamento de Microbiologia Geral, Instituto de Microbiologia, Universidade Federal do Rio de Janeiro, CCS, Bloco I, Cidade Universitária, 21941-590 Rio de Janeiro, RJ, Brazil
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