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Arbulu S, Kjos M. Revisiting the Multifaceted Roles of Bacteriocins : The Multifaceted Roles of Bacteriocins. MICROBIAL ECOLOGY 2024; 87:41. [PMID: 38351266 PMCID: PMC10864542 DOI: 10.1007/s00248-024-02357-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/08/2023] [Accepted: 02/01/2024] [Indexed: 02/16/2024]
Abstract
Bacteriocins are gene-encoded antimicrobial peptides produced by bacteria. These peptides are heterogeneous in terms of structure, antimicrobial activities, biosynthetic clusters, and regulatory mechanisms. Bacteriocins are widespread in nature and may contribute to microbial diversity due to their capacity to target specific bacteria. Primarily studied as food preservatives and therapeutic agents, their function in natural settings is however less known. This review emphasizes the ecological significance of bacteriocins as multifunctional peptides by exploring bacteriocin distribution, mobility, and their impact on bacterial population dynamics and biofilms.
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Affiliation(s)
- Sara Arbulu
- Faculty of Chemistry, Biotechnology and Food Science, Norwegian University of Life Sciences, Ås, Norway.
| | - Morten Kjos
- Faculty of Chemistry, Biotechnology and Food Science, Norwegian University of Life Sciences, Ås, Norway.
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2
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Kita K, Yoshida S, Masuo S, Nakamura A, Ishikawa S, Yoshida KI. Genes encoding a novel thermostable bacteriocin in the thermophilic bacterium Aeribacillus pallidus PI8. J Appl Microbiol 2023; 134:lxad293. [PMID: 38040658 DOI: 10.1093/jambio/lxad293] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2023] [Revised: 11/10/2023] [Accepted: 11/30/2023] [Indexed: 12/03/2023]
Abstract
AIM Aeribacillus pallidus PI8 is a Gram-positive thermophilic bacterium that produces thermostable antimicrobial substances against several bacterial species, including Geobacillus kaustophilus HTA426. In the present study, we sought to identify genes of PI8 with antibacterial activity. METHODS AND RESULTS We isolated, cloned, and characterized a thermostable bacteriocin from A. pallidus PI8 and named it pallidocyclin. Mass spectrometric analyses of pallidocyclin revealed that it had a circular peptide structure, and its precursor was encoded by pcynA in the PI8 genome. pcynA is the second gene within the pcynBACDEF operon. Expression of the full-length pcynBACDEF operon in Bacillus subtilis produced intact pallidocyclin, whereas expression of pcynF in G. kaustophilus HTA426 conferred resistance to pallidocyclin. CONCLUSION Aeribacillus pallidus PI8 possesses the pcynBACDEF operon to produce pallidocyclin. pcynA encodes the pallidocyclin precursor, and pcynF acts as an antagonist of pallidocyclin.
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Affiliation(s)
- Kyosuke Kita
- Department of Science, Technology, and Innovation, Kobe University, 1-1 Rokkodai, Nada, Kobe 657-8501, Japan
| | - Sanako Yoshida
- Department of Science, Technology, and Innovation, Kobe University, 1-1 Rokkodai, Nada, Kobe 657-8501, Japan
| | - Shunsuke Masuo
- Faculty of Life and Environmental Sciences, University of Tsukuba, 1-1-1 Tennodai, Tsukuba 305-8572 Ibaraki, Japan
- Microbiology Research Center for Sustainability, University of Tsukuba, 1-1-1 Tennodai, Tsukuba 305-8572 Ibaraki, Japan
| | - Akira Nakamura
- Faculty of Life and Environmental Sciences, University of Tsukuba, 1-1-1 Tennodai, Tsukuba 305-8572 Ibaraki, Japan
- Microbiology Research Center for Sustainability, University of Tsukuba, 1-1-1 Tennodai, Tsukuba 305-8572 Ibaraki, Japan
| | - Shu Ishikawa
- Department of Science, Technology, and Innovation, Kobe University, 1-1 Rokkodai, Nada, Kobe 657-8501, Japan
| | - Ken-Ichi Yoshida
- Department of Science, Technology, and Innovation, Kobe University, 1-1 Rokkodai, Nada, Kobe 657-8501, Japan
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3
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Ladjouzi R, Dussert E, Teiar R, Belguesmia Y, Drider D. A Review on Enterocin DD14, the Leaderless Two-Peptide Bacteriocin with Multiple Biological Functions and Unusual Transport Pathway. Antibiotics (Basel) 2023; 12:1188. [PMID: 37508284 PMCID: PMC10376788 DOI: 10.3390/antibiotics12071188] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2023] [Revised: 07/09/2023] [Accepted: 07/11/2023] [Indexed: 07/30/2023] Open
Abstract
Enterocin DD14 (EntDD14) is a two-peptide leaderless bacteriocin (LLB) produced by Enterococcus faecalis 14, a human strain isolated from meconium. Studies performed on EntDD14 enabled it to show its activity against Gram-positive bacteria such as Listeria monocytogenes, Clostridium perfringens, Enterococcus faecalis, and Staphylococcus aureus. EntDD14 was also shown to potentiate the activity of different antibiotics such as erythromycin, kanamycin, and methicillin when assessed against methicillin-resistant Staphylococcus aureus (MRSA) in vitro and in vivo in the NMRI-F holoxenic mouse model. Additionally, EntDD14 has an antiviral activity and decreased the secretion of pro-inflammatory IL-6 and IL-8 in inflamed human intestinal Caco-2 cells. The genome of E. faecalis 14 was sequenced and annotated. Molecular tools such as Bagel4 software enabled us to locate a 6.7kb-EntDD14 cluster. Transport of EntDD14 outside of the cytoplasm was shown to be performed synergistically by a channel composed of two pleckstrin-homology-domain-containing proteins, namely DdE/DdF and the ABC transporter DdGHIJ. This latter could also protect the bacteriocinogenic strain against extracellular EntDD14. Here, we focus on academic data and potential therapeutic issues of EntDD14, as a model of two-peptide LLB.
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Affiliation(s)
- Rabia Ladjouzi
- UMR Transfrontalière BioEcoAgro, INRAe 1158, ICV-Institut Charles Viollette, University Lille, INRAE, University Liège, UPJV, YNCREA, University Artois, University Littoral Côte d'Opale, F-59000 Lille, France
| | - Elodie Dussert
- UMR Transfrontalière BioEcoAgro, INRAe 1158, ICV-Institut Charles Viollette, University Lille, INRAE, University Liège, UPJV, YNCREA, University Artois, University Littoral Côte d'Opale, F-59000 Lille, France
| | - Radja Teiar
- UMR Transfrontalière BioEcoAgro, INRAe 1158, ICV-Institut Charles Viollette, University Lille, INRAE, University Liège, UPJV, YNCREA, University Artois, University Littoral Côte d'Opale, F-59000 Lille, France
| | - Yanath Belguesmia
- UMR Transfrontalière BioEcoAgro, INRAe 1158, ICV-Institut Charles Viollette, University Lille, INRAE, University Liège, UPJV, YNCREA, University Artois, University Littoral Côte d'Opale, F-59000 Lille, France
| | - Djamel Drider
- UMR Transfrontalière BioEcoAgro, INRAe 1158, ICV-Institut Charles Viollette, University Lille, INRAE, University Liège, UPJV, YNCREA, University Artois, University Littoral Côte d'Opale, F-59000 Lille, France
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4
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Cebrián R, Martínez-García M, Fernández M, García F, Martínez-Bueno M, Valdivia E, Kuipers OP, Montalbán-López M, Maqueda M. Advances in the preclinical characterization of the antimicrobial peptide AS-48. Front Microbiol 2023; 14:1110360. [PMID: 36819031 PMCID: PMC9936517 DOI: 10.3389/fmicb.2023.1110360] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2022] [Accepted: 01/11/2023] [Indexed: 02/05/2023] Open
Abstract
Antimicrobial resistance is a natural and inevitable phenomenon that constitutes a severe threat to global public health and economy. Innovative products, active against new targets and with no cross- or co-resistance with existing antibiotic classes, novel mechanisms of action, or multiple therapeutic targets are urgently required. For these reasons, antimicrobial peptides such as bacteriocins constitute a promising class of new antimicrobial drugs under investigation for clinical development. Here, we review the potential therapeutic use of AS-48, a head-to-tail cyclized cationic bacteriocin produced by Enterococcus faecalis. In the last few years, its potential against a wide range of human pathogens, including relevant bacterial pathogens and trypanosomatids, has been reported using in vitro tests and the mechanism of action has been investigated. AS-48 can create pores in the membrane of bacterial cells without the mediation of any specific receptor. However, this mechanism of action is different when susceptible parasites are studied and involves intracellular targets. Due to these novel mechanisms of action, AS-48 remains active against the antibiotic resistant strains tested. Remarkably, the effect of AS-48 against eukaryotic cell lines and in several animal models show little effect at the doses needed to inhibit susceptible species. The characteristics of this molecule such as low toxicity, microbicide activity, blood stability and activity, high stability at a wide range of temperatures or pH, resistance to proteases, and the receptor-independent effect make AS-48 unique to fight a broad range of microbial infections, including bacteria and some important parasites.
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Affiliation(s)
- Rubén Cebrián
- Department of Clinical Microbiology, Instituto de Investigación Biosanitaria Ibs.GRANADA, University Hospital San Cecilio, Granada, Spain,*Correspondence: Rubén Cebrián, ✉
| | | | | | - Federico García
- Department of Clinical Microbiology, Instituto de Investigación Biosanitaria Ibs.GRANADA, University Hospital San Cecilio, Granada, Spain,Biomedicinal Research Network Center, Infectious Diseases (CIBERINFEC), Madrid, Spain
| | | | - Eva Valdivia
- Department of Microbiology, University of Granada, Granada, Spain
| | - Oscar P. Kuipers
- Department of Molecular Genetics, University of Groningen, Groningen, Netherlands
| | - Manuel Montalbán-López
- Department of Microbiology, University of Granada, Granada, Spain,Manuel Montalbán-López, ✉
| | - Mercedes Maqueda
- Department of Microbiology, University of Granada, Granada, Spain
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Pérez-Ramos A, Ladjouzi R, Mihasan M, Teiar R, Benachour A, Drider D. Advances in Characterizing the Transport Systems of and Resistance to EntDD14, A Leaderless Two-Peptide Bacteriocin with Potent Inhibitory Activity. Int J Mol Sci 2023; 24:ijms24021517. [PMID: 36675049 PMCID: PMC9865063 DOI: 10.3390/ijms24021517] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2022] [Revised: 01/06/2023] [Accepted: 01/08/2023] [Indexed: 01/15/2023] Open
Abstract
Enterocin DD14 (EntDD14) is a two-peptide leaderless bacteriocin produced by the Enterococcus faecalis 14 strain previously isolated from meconium. This bacteriocin is mainly active against Gram-positive bacteria. Leaderless bacteriocins do not undergo post-translational modifications and are therefore immediately active after their synthesis. As a result, the cells that produce such bacteriocins have developed means of protection against them which often involve transport systems. In this and our previous work, we constructed different mutants deleted in the genes involved in the transport functions, thus covering all the supposed components of this transport system, using Listeria innocua ATCC 33090 as the indicator strain to assess the activity of externalized EntDD14. We also assessed the self-resistance of the WT and all its engineered derivative mutants against EntDD14, provided extracellularly, in order to evaluate their self-resistance. The results obtained highlight that the ABC transporter constituted by the DdG, H, I, and J proteins contributes to EntDD14 export as well as resistance to an external supply of EntDD14. Our results also have established the essential role of the DdE and DdF proteins as primary transporters dedicated to the externalization of EntDD14. Moreover, the in silico data showed that DdE and DdF appear to assemble in a formation that forms an essential channel for the exit of EntDD14. This channel DdEF may interact with the ABC transporter DdGHIJ in order to control the flow of bacteriocin across the membrane, although the nature of this interaction remains to be elucidated.
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Affiliation(s)
- Adrián Pérez-Ramos
- ICV-Institut Charles Viollette, UMR Transfrontalière BioEcoAgro 1158, University Lille, INRAE, University Liège, UPJV, YNCREA, University Artois, University Littoral Côte d’Opale, 59000 Lille, France
| | - Rabia Ladjouzi
- ICV-Institut Charles Viollette, UMR Transfrontalière BioEcoAgro 1158, University Lille, INRAE, University Liège, UPJV, YNCREA, University Artois, University Littoral Côte d’Opale, 59000 Lille, France
| | - Marius Mihasan
- Biochemistry and Molecular Biology Laboratory, Faculty of Biology, Alexandru Ioan Cuza University of Iasi, Carol I Blvd, no. 20A, 700506 Iasi, Romania
| | - Radja Teiar
- ICV-Institut Charles Viollette, UMR Transfrontalière BioEcoAgro 1158, University Lille, INRAE, University Liège, UPJV, YNCREA, University Artois, University Littoral Côte d’Opale, 59000 Lille, France
| | - Abdellah Benachour
- U2RM-Stress and Virulence, UNICAEN, Esplanade de la Paix, 14000 Caen, France
| | - Djamel Drider
- ICV-Institut Charles Viollette, UMR Transfrontalière BioEcoAgro 1158, University Lille, INRAE, University Liège, UPJV, YNCREA, University Artois, University Littoral Côte d’Opale, 59000 Lille, France
- Correspondence:
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6
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Evidence for the Involvement of Pleckstrin Homology Domain-Containing Proteins in the Transport of Enterocin DD14 (EntDD14); a Leaderless Two-Peptide Bacteriocin. Int J Mol Sci 2021; 22:ijms222312877. [PMID: 34884682 PMCID: PMC8657885 DOI: 10.3390/ijms222312877] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2021] [Revised: 11/22/2021] [Accepted: 11/25/2021] [Indexed: 01/07/2023] Open
Abstract
Bacteriocins synthesis is initiated from an inactive precursor, which is composed of an N-terminal leader peptide attached to a C-terminal pro-peptide. However, leaderless bacteriocins (LLB) do not possess this N-terminal leader peptide nor undergo post-translational modifications. These atypical bacteriocins are observed to be immediately active after their translation in the cytoplasm. However, although considered to be simple, the biosynthetic pathway of LLB remains to be fully understood. Enterocin DD14 (EntDD14) is a two-peptide LLB produced by Enterococcus faecalis 14, which is a strain isolated from meconium. In silico analysis of DNA encoding EntDD14 located a cluster of 10 genes ddABCDEFGHIJ, where ddE and ddF encode the peculiar DdE and DdF proteins, carrying pleckstrin homology (PH) domains. These modules are quite common in Eucarya proteins and are known to be involved in intracellular signaling or cytoskeleton organization. To elucidate their role within the EntDD14 genetic determinants, we constructed deletion mutants of the ddE and ddF genes. As a result, the mutants were unable to export EntDD14 outside of the cytoplasm even though there was a clear expression of structural genes ddAB encoding EntDD14, and genes ddHIJ encoding an ABC transporter. Importantly, in these mutant strains (ΔddE and ΔddF), EntDD14 was detected by mass spectrometry in the intracellular soluble fraction exerting, upon its accumulation, a toxic effect on the producing strain as revealed by cell-counting and confocal microscopy analysis. Taken together, these results clearly indicate that PH domain-containing proteins, such as DdE and DdF, are involved in the transport of the leaderless two-peptide EntDD14.
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7
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Pérez-Ramos A, Madi-Moussa D, Coucheney F, Drider D. Current Knowledge of the Mode of Action and Immunity Mechanisms of LAB-Bacteriocins. Microorganisms 2021; 9:2107. [PMID: 34683428 PMCID: PMC8538875 DOI: 10.3390/microorganisms9102107] [Citation(s) in RCA: 41] [Impact Index Per Article: 13.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2021] [Revised: 09/28/2021] [Accepted: 09/29/2021] [Indexed: 12/31/2022] Open
Abstract
Bacteriocins produced by lactic acid bacteria (LAB-bacteriocins) may serve as alternatives for aging antibiotics. LAB-bacteriocins can be used alone, or in some cases as potentiating agents to treat bacterial infections. This approach could meet the different calls and politics, which aim to reduce the use of traditional antibiotics and develop novel therapeutic options. Considering the clinical applications of LAB-bacteriocins as a reasonable and desirable therapeutic approach, it is therefore important to assess the advances achieved in understanding their modes of action, and the resistance mechanisms developed by the producing bacteria to their own bacteriocins. Most LAB-bacteriocins act by disturbing the cytoplasmic membrane through forming pores, or by cell wall degradation. Nevertheless, some of these peptides still have unknown modes of action, especially those that are active against Gram-negative bacteria. Regarding immunity, most bacteriocin-producing strains have an immunity mechanism involving an immunity protein and a dedicated ABC transporter system. However, these immunity mechanisms vary from one bacteriocin to another.
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Affiliation(s)
| | | | | | - Djamel Drider
- UMR Transfrontalière BioEcoAgro 1158, Univ. Lille, INRAE, Univ. Liège, UPJV, YNCREA, Univ. Artois, Univ. Littoral Côte d’Opale, ICV—Institut Charles Viollette, F-59000 Lille, France; (A.P.-R.); (D.M.-M.); (F.C.)
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8
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Teso-Pérez C, Martínez-Bueno M, Peralta-Sánchez JM, Valdivia E, Maqueda M, Fárez-Vidal ME, Martín-Platero AM. Enterocin Cross-Resistance Mediated by ABC Transport Systems. Microorganisms 2021; 9:microorganisms9071411. [PMID: 34208875 PMCID: PMC8306556 DOI: 10.3390/microorganisms9071411] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2021] [Revised: 06/25/2021] [Accepted: 06/25/2021] [Indexed: 11/26/2022] Open
Abstract
In their struggle for life, bacteria frequently produce antagonistic substances against competitors. Antimicrobial peptides produced by bacteria (known as bacteriocins) are active against other bacteria, but harmless to their producer due to an associated immunity gene that prevents self-inhibition. However, knowledge of cross-resistance between different types of bacteriocin producer remains very limited. The immune function of certain bacteriocins produced by the Enterococcus genus (known as enterocins) is mediated by an ABC transporter. This is the case for enterocin AS-48, a gene cluster that includes two ABC transporter-like systems (Transporter-1 and 2) and an immunity protein. Transporter-2 in this cluster shows a high similarity to the ABC transporter-like system in MR10A and MR10B enterocin gene clusters. The aim of our study was to determine the possible role of this ABC transporter in cross-resistance between these two different types of enterocin. To this end, we designed different mutants (Tn5 derivative and deletion mutants) of the as-48 gene cluster in Enterococcus faecalis and cloned them into the pAM401 shuttle vector. Antimicrobial activity assays showed that enterocin AS-48 Transporter-2 is responsible for cross-resistance between AS-48 and MR10A/B enterocin producers and allowed identification of the MR10A/B immunity gene system. These findings open the way to the investigation of resistance beyond homologous bacteriocins.
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Affiliation(s)
- Claudia Teso-Pérez
- Departamento de Microbiología, Universidad de Granada, Avda. Fuentenueva s/n, 18071 Granada, Spain; (M.M.-B.); (J.M.P.-S.); (E.V.); (M.M.)
- Correspondence: (C.T.-P.); (M.E.F.-V.); (A.M.M.-P.)
| | - Manuel Martínez-Bueno
- Departamento de Microbiología, Universidad de Granada, Avda. Fuentenueva s/n, 18071 Granada, Spain; (M.M.-B.); (J.M.P.-S.); (E.V.); (M.M.)
| | - Juan Manuel Peralta-Sánchez
- Departamento de Microbiología, Universidad de Granada, Avda. Fuentenueva s/n, 18071 Granada, Spain; (M.M.-B.); (J.M.P.-S.); (E.V.); (M.M.)
| | - Eva Valdivia
- Departamento de Microbiología, Universidad de Granada, Avda. Fuentenueva s/n, 18071 Granada, Spain; (M.M.-B.); (J.M.P.-S.); (E.V.); (M.M.)
| | - Mercedes Maqueda
- Departamento de Microbiología, Universidad de Granada, Avda. Fuentenueva s/n, 18071 Granada, Spain; (M.M.-B.); (J.M.P.-S.); (E.V.); (M.M.)
| | - M. Esther Fárez-Vidal
- Departamento de Bioquímica y Biología Molecular III e Inmunología, Facultad de Medicina, Universidad de Granada, 18016 Granada, Spain
- Instituto de Investigación Biomédica IBS, Granada, Complejo Hospitalario Universitario de Granada, Universidad de Granada, 18071 Granada, Spain
- Correspondence: (C.T.-P.); (M.E.F.-V.); (A.M.M.-P.)
| | - Antonio M. Martín-Platero
- Departamento de Microbiología, Universidad de Granada, Avda. Fuentenueva s/n, 18071 Granada, Spain; (M.M.-B.); (J.M.P.-S.); (E.V.); (M.M.)
- Correspondence: (C.T.-P.); (M.E.F.-V.); (A.M.M.-P.)
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Ladjouzi R, Lucau-Danila A, Benachour A, Drider D. A Leaderless Two-Peptide Bacteriocin, Enterocin DD14, Is Involved in Its Own Self-Immunity: Evidence and Insights. Front Bioeng Biotechnol 2020; 8:644. [PMID: 32671042 PMCID: PMC7332713 DOI: 10.3389/fbioe.2020.00644] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2020] [Accepted: 05/26/2020] [Indexed: 12/28/2022] Open
Abstract
Enterocin DD14 (EntDD14) is a two-peptide leaderless bacteriocin produced by Enterococcus faecalis 14, a strain previously isolated from meconium. EntDD14 has a strong antibacterial activity against Gram-positive bacteria. Leaderless bacteriocins, unlike bacteriocins with leader peptides, are immediately active after their translation, and a producing strain has then to develop specific mechanisms to protect both intra and extracellular compartments. The in silico analysis of Ent. faecalis 14 genome allowed to locate downstream of structural ddAB genes, 8 other adjacent genes, designed ddCDEFGHIJ, which collectively may form three operons. To gain insights on immunity mechanisms of Ent. faecalis 14, mutant strains knocked out in ddAB genes encoding bacteriocin precursor peptides (Δbac) and/or ABC transporter (ΔddI) of EntDD14 were constructed and characterized. Importantly, Δbac mutant strains, from which structural ddAB genes were deleted, resulted unable to produce EntDD14 and sensitive to exogenous EntDD14 showing their involvement in the Ent. faecalis 14 immunity system. Moreover, the sensitivity of Δbac mutants appeared not to be associated with the down-regulation of ddCDEFGHIJ gene expression since they were similarly expressed in both Δbac and wild-type strains during the log phase while they were found significantly down-regulated in the Δbac mutant strain after 24 h of growth. Data gathered from this study suggest also the implication of the ABC transporter (ddHIJ) in the active export of EntDD14 but ruled-out its involvement in the primary self-immunity system. Interestingly, non-bacteriocin producing Ent. faecalis JH2-2 cells transformed with ddAB, or ddAB plus genes encoding the ABC transporter (ddAB-HIJ) did not produce EntDD14 and remained sensitive to its action. Of note, trans-complementation of the Δbac mutant strain with these constructions allowed to recover the WT phenotype. To the best of our knowledge, this is the first study delineating the role of the intracellular two-peptide leaderless bacteriocins in their self-immunity.
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Affiliation(s)
- Rabia Ladjouzi
- UMR Transfrontalière BioEcoAgro N° 1158, Univ. Lille, INRAE, Univ. Liège, UPJV, YNCREA, Univ. Artois, Univ. Littoral Côte d'Opale, ICV - Institut Charles Viollette, Lille, France
| | - Anca Lucau-Danila
- UMR Transfrontalière BioEcoAgro N° 1158, Univ. Lille, INRAE, Univ. Liège, UPJV, YNCREA, Univ. Artois, Univ. Littoral Côte d'Opale, ICV - Institut Charles Viollette, Lille, France
| | | | - Djamel Drider
- UMR Transfrontalière BioEcoAgro N° 1158, Univ. Lille, INRAE, Univ. Liège, UPJV, YNCREA, Univ. Artois, Univ. Littoral Côte d'Opale, ICV - Institut Charles Viollette, Lille, France
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10
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Genome mining for ribosomally synthesised and post-translationally modified peptides (RiPPs) reveals undiscovered bioactive potentials of actinobacteria. Antonie van Leeuwenhoek 2019; 112:1477-1499. [DOI: 10.1007/s10482-019-01276-6] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/03/2019] [Accepted: 05/14/2019] [Indexed: 01/22/2023]
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11
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Miljkovic M, Lozo J, Mirkovic N, O'Connor PM, Malesevic M, Jovcic B, Cotter PD, Kojic M. Functional Characterization of the Lactolisterin BU Gene Cluster of Lactococcus lactis subsp. lactis BGBU1-4. Front Microbiol 2018; 9:2774. [PMID: 30498487 PMCID: PMC6249370 DOI: 10.3389/fmicb.2018.02774] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2018] [Accepted: 10/29/2018] [Indexed: 11/13/2022] Open
Abstract
The gene cluster responsible for the production of the aureocin A53-like bacteriocin, lactolisterin BU, is located on plasmid pBU6 in Lactococcus lactis subsp. lactis BGBU1-4. Heterologous expression of pBU6 confirmed that production and limited immunity to lactolisterin BU were provided by the plasmid. Comparative analysis of aureocin A53-like operons revealed that the structural genes shared a low level of identity, while other genes were without homology, indicating a different origin. Subcloning and expression of genes located downstream of the structural gene, lliBU, revealed that the lactolisterin BU cluster consists of four genes: the structural gene lliBU, the abcT gene encoding an ABC transporter, the accL gene encoding an accessory protein and the immL gene which provides limited immunity to lactolisterin BU. Reverse transcription analysis revealed that all genes were transcribed as one polycistronic mRNA. Attempts to split the lactolisterin BU operon, even when both parts were under control of the PlliBU promoter, were unsuccessful indicating that expression of lactolisterin BU is probably precisely regulated at the translational level by translational coupling and is possible only when all genes of the operon are in cis constellation. Two ρ-independent transcription terminators were detected in the lactolisterin BU operon: the first in the intergenic region of the lliBU and abcT genes and the second at the end of operon. Deletion of the second transcription terminator did not influence production of the bacteriocin in lactococci.
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Affiliation(s)
- Marija Miljkovic
- Laboratory for Molecular Microbiology, Institute of Molecular Genetics and Genetic Engineering, University of Belgrade, Belgrade, Serbia
| | - Jelena Lozo
- Laboratory for Molecular Microbiology, Institute of Molecular Genetics and Genetic Engineering, University of Belgrade, Belgrade, Serbia.,Faculty of Biology, University of Belgrade, Belgrade, Serbia
| | - Nemanja Mirkovic
- Laboratory for Molecular Microbiology, Institute of Molecular Genetics and Genetic Engineering, University of Belgrade, Belgrade, Serbia
| | - Paula M O'Connor
- Teagasc Food Research Centre, Moorepark, Fermoy, Ireland.,APC Microbiome Ireland, University College Cork, Cork, Ireland
| | - Milka Malesevic
- Laboratory for Molecular Microbiology, Institute of Molecular Genetics and Genetic Engineering, University of Belgrade, Belgrade, Serbia
| | - Branko Jovcic
- Laboratory for Molecular Microbiology, Institute of Molecular Genetics and Genetic Engineering, University of Belgrade, Belgrade, Serbia.,Faculty of Biology, University of Belgrade, Belgrade, Serbia
| | - Paul D Cotter
- Teagasc Food Research Centre, Moorepark, Fermoy, Ireland.,APC Microbiome Ireland, University College Cork, Cork, Ireland
| | - Milan Kojic
- Laboratory for Molecular Microbiology, Institute of Molecular Genetics and Genetic Engineering, University of Belgrade, Belgrade, Serbia
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12
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Perez RH, Zendo T, Sonomoto K. Circular and Leaderless Bacteriocins: Biosynthesis, Mode of Action, Applications, and Prospects. Front Microbiol 2018; 9:2085. [PMID: 30233551 PMCID: PMC6131525 DOI: 10.3389/fmicb.2018.02085] [Citation(s) in RCA: 98] [Impact Index Per Article: 16.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2018] [Accepted: 08/15/2018] [Indexed: 01/02/2023] Open
Abstract
Bacteriocins are a huge family of ribosomally synthesized peptides known to exhibit a range of bioactivities, most predominantly antibacterial activities. Bacteriocins from lactic acid bacteria are of particular interest due to the latter's association to food fermentation and the general notion of them to be safe. Among the family of bacteriocins, the groups known as circular bacteriocins and leaderless bacteriocins are gaining more attention due to their enormous potential for industrial application. Circular bacteriocins and leaderless bacteriocins, arguably the least understood groups of bacteriocins, possess distinctively peculiar characteristics in their structures and biosynthetic mechanisms. Circular bacteriocins have N-to-C- terminal covalent linkage forming a structurally distinct circular peptide backbone. The circular nature of their structures provides them superior stability against various stresses compared to most linear bacteriocins. The molecular mechanism of their biosynthesis, albeit has remained poorly understood, is believed to possesses huge application prospect as it can serve as scaffold in bioengineering other biologically important peptides. On the other hand, while most bacteriocins are synthesized as inactive precursor peptides, which possess an N-terminal leader peptide attached to a C-terminal propeptide, leaderless bacteriocins are atypical as they do not have an N-terminal leader peptide, hence the name. Leaderless bacteriocins are active right after translation as they do not undergo any post-translational processing common to other groups of bacteriocins. This "simplicity" in the biosynthesis of leaderless bacteriocins offers a huge commercial potential as scale-up production systems are considerably easier to assemble. In this review, we summarize the current studies of both circular and leaderless bacteriocins, highlighting the progress in understanding their biosynthesis, mode of action, application and their prospects.
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Affiliation(s)
- Rodney H Perez
- Department of Bioscience and Biotechnology, Faculty of Agriculture, Graduate School, Kyushu University, Fukuoka, Japan.,National Institute of Molecular Biology and Biotechnology, University of the Philippines Los Baños, Los Baños, Philippines
| | - Takeshi Zendo
- Department of Bioscience and Biotechnology, Faculty of Agriculture, Graduate School, Kyushu University, Fukuoka, Japan
| | - Kenji Sonomoto
- Department of Bioscience and Biotechnology, Faculty of Agriculture, Graduate School, Kyushu University, Fukuoka, Japan
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13
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Greene NP, Kaplan E, Crow A, Koronakis V. Antibiotic Resistance Mediated by the MacB ABC Transporter Family: A Structural and Functional Perspective. Front Microbiol 2018; 9:950. [PMID: 29892271 PMCID: PMC5985334 DOI: 10.3389/fmicb.2018.00950] [Citation(s) in RCA: 93] [Impact Index Per Article: 15.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2018] [Accepted: 04/24/2018] [Indexed: 12/18/2022] Open
Abstract
The MacB ABC transporter forms a tripartite efflux pump with the MacA adaptor protein and TolC outer membrane exit duct to expel antibiotics and export virulence factors from Gram-negative bacteria. Here, we review recent structural and functional data on MacB and its homologs. MacB has a fold that is distinct from other structurally characterized ABC transporters and uses a unique molecular mechanism termed mechanotransmission. Unlike other bacterial ABC transporters, MacB does not transport substrates across the inner membrane in which it is based, but instead couples cytoplasmic ATP hydrolysis with transmembrane conformational changes that are used to perform work in the extra-cytoplasmic space. In the MacAB-TolC tripartite pump, mechanotransmission drives efflux of antibiotics and export of a protein toxin from the periplasmic space via the TolC exit duct. Homologous tripartite systems from pathogenic bacteria similarly export protein-like signaling molecules, virulence factors and siderophores. In addition, many MacB-like ABC transporters do not form tripartite pumps, but instead operate in diverse cellular processes including antibiotic sensing, cell division and lipoprotein trafficking.
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Affiliation(s)
- Nicholas P Greene
- Department of Pathology, University of Cambridge, Cambridge, United Kingdom
| | - Elise Kaplan
- Department of Pathology, University of Cambridge, Cambridge, United Kingdom
| | - Allister Crow
- School of Life Sciences, University of Warwick, Coventry, United Kingdom
| | - Vassilis Koronakis
- Department of Pathology, University of Cambridge, Cambridge, United Kingdom
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14
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van Heel AJ, Montalban-Lopez M, Oliveau Q, Kuipers OP. Genome-guided identification of novel head-to-tail cyclized antimicrobial peptides, exemplified by the discovery of pumilarin. Microb Genom 2017; 3:e000134. [PMID: 29177092 PMCID: PMC5695211 DOI: 10.1099/mgen.0.000134] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2017] [Accepted: 09/01/2017] [Indexed: 11/18/2022] Open
Abstract
The need for novel antibiotics in an era where antimicrobial resistance is on the rise, and the number of new approved antimicrobial drugs reaching the market is declining, is evident. The underused potential of post-translationally modified peptides for clinical use makes this class of peptides interesting candidates. In this study, we made use of the vast amounts of available genomic data and screened all publicly available prokaryotic genomes (~3000) to identify 394 novel head-to-tail cyclized antimicrobial peptides. To verify these in silico results, we isolated and characterized a novel antimicrobial peptide from Bacillus pumilus that we named pumilarin. Pumilarin was demonstrated to have a circular structure and showed antimicrobial activity against several indicator strains, including pathogens.
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Affiliation(s)
- Auke J van Heel
- 1Molecular Genetics, University of Groningen, Groningen, Nijenborgh 7, NA 9747 AG, The Netherlands
| | - Manuel Montalban-Lopez
- 1Molecular Genetics, University of Groningen, Groningen, Nijenborgh 7, NA 9747 AG, The Netherlands.,2Department of Microbiology, University of Granada, Granada, Spain
| | - Quentin Oliveau
- 1Molecular Genetics, University of Groningen, Groningen, Nijenborgh 7, NA 9747 AG, The Netherlands
| | - Oscar P Kuipers
- 1Molecular Genetics, University of Groningen, Groningen, Nijenborgh 7, NA 9747 AG, The Netherlands
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15
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Bartholomae M, Buivydas A, Viel JH, Montalbán-López M, Kuipers OP. Major gene-regulatory mechanisms operating in ribosomally synthesized and post-translationally modified peptide (RiPP) biosynthesis. Mol Microbiol 2017; 106:186-206. [DOI: 10.1111/mmi.13764] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2017] [Revised: 08/02/2017] [Accepted: 08/03/2017] [Indexed: 02/06/2023]
Affiliation(s)
- Maike Bartholomae
- Department of Molecular Genetics; University of Groningen, Nijenborgh 7; 9747AG Groningen The Netherlands
| | - Andrius Buivydas
- Department of Molecular Genetics; University of Groningen, Nijenborgh 7; 9747AG Groningen The Netherlands
| | - Jakob H. Viel
- Department of Molecular Genetics; University of Groningen, Nijenborgh 7; 9747AG Groningen The Netherlands
| | - Manuel Montalbán-López
- Department of Microbiology; University of Granada, C. Fuentenueva s/n; 18071 Granada Spain
| | - Oscar P. Kuipers
- Department of Molecular Genetics; University of Groningen, Nijenborgh 7; 9747AG Groningen The Netherlands
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16
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Kim EB, Jin GD, Lee JY, Choi YJ. Genomic Features and Niche-Adaptation of Enterococcus faecium Strains from Korean Soybean-Fermented Foods. PLoS One 2016; 11:e0153279. [PMID: 27070419 PMCID: PMC4829236 DOI: 10.1371/journal.pone.0153279] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2015] [Accepted: 03/25/2016] [Indexed: 01/19/2023] Open
Abstract
Certain strains of Enterococcus faecium contribute beneficially to human health and food fermentation. However, other E. faecium strains are opportunistic pathogens due to the acquisition of virulence factors and antibiotic resistance determinants. To characterize E. faecium from soybean fermentation, we sequenced the genomes of 10 E. faecium strains from Korean soybean-fermented foods and analyzed their genomes by comparing them with 51 clinical and 52 non-clinical strains of different origins. Hierarchical clustering based on 13,820 orthologous genes from all E. faecium genomes showed that the 10 strains are distinguished from most of the clinical strains. Like non-clinical strains, their genomes are significantly smaller than clinical strains due to fewer accessory genes associated with antibiotic resistance, virulence, and mobile genetic elements. Moreover, we identified niche-associated gene gain and loss from the soybean strains. Thus, we conclude that soybean E. faecium strains might have evolved to have distinctive genomic features that may contribute to its ability to thrive during soybean fermentation.
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Affiliation(s)
- Eun Bae Kim
- Department of Animal Life Science, College of Animal Life Sciences, Kangwon National University, Chuncheon, Kangwon-do, Republic of Korea
- Division of Applied Animal Science, College of Animal Life Sciences, Kangwon National University, Chuncheon, Kangwon-do, Republic of Korea
| | - Gwi-Deuk Jin
- Department of Animal Life Science, College of Animal Life Sciences, Kangwon National University, Chuncheon, Kangwon-do, Republic of Korea
| | - Jun-Yeong Lee
- Department of Agricultural Biotechnology, Seoul National University, Seoul, Republic of Korea
| | - Yun-Jaie Choi
- Department of Agricultural Biotechnology, Seoul National University, Seoul, Republic of Korea
- Research Institute for Agriculture and Life Science, Seoul National University, Seoul, Republic of Korea
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17
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van Belkum MJ, Martin-Visscher LA, Vederas JC. Cloning and Characterization of the Gene Cluster Involved in the Production of the Circular Bacteriocin Carnocyclin A. Probiotics Antimicrob Proteins 2016; 2:218-25. [PMID: 26781316 DOI: 10.1007/s12602-010-9056-1] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
Abstract
Carnocyclin A is a circular bacteriocin of 60 amino acids produced by Carnobacterium maltaromaticum UAL307. A region of 12 kb that contained the structural gene for carnocyclin A, cclA, was sequenced using a fosmid library, and 10 genes were identified that could be responsible for carnocyclin A production and immunity. Five of those genes, cclBITCD, were found upstream of cclA: one encodes a protein containing a conserved ATP-binding domain and four encode proteins with putative membrane-spanning domains. CclC shows homology with a family of membrane proteins that contain the domain of unknown function 95 (DUF95). Downstream of cclA four additional genes, cclEFGH, were identified that show similarity to the last four genes, as-48EFGH, of the enterocin AS-48 bacteriocin gene cluster. CclFGH shows sequence homology with As-48FGH. Transformation of C. maltaromaticum UAL26 with cclBITCDA resulted in production of carnocyclin A, indicating that these genes form the minimal requirement for the secretion of fully matured bacteriocin. cclI encodes for a small hydrophobic protein with a high pI, which are characteristic features of known immunity proteins for other circular bacteriocins. Indeed, cloning of cclI behind a constitutive promoter in UAL26 resulted in immunity although the level of resistance was lower than that of UAL26 containing cclBITCDA, indicating that CclI alone is not enough to confer full immunity to carnocyclin A.
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Affiliation(s)
- Marco J van Belkum
- Department of Chemistry, University of Alberta, Edmonton, AB, T6G 2G2, Canada.
| | | | - John C Vederas
- Department of Chemistry, University of Alberta, Edmonton, AB, T6G 2G2, Canada
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18
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Bogaardt C, van Tonder AJ, Brueggemann AB. Genomic analyses of pneumococci reveal a wide diversity of bacteriocins - including pneumocyclicin, a novel circular bacteriocin. BMC Genomics 2015. [PMID: 26215050 PMCID: PMC4517551 DOI: 10.1186/s12864-015-1729-4] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023] Open
Abstract
Background One of the most important global pathogens infecting all age groups is Streptococcus pneumoniae (the ‘pneumococcus’). Pneumococci reside in the paediatric nasopharynx, where they compete for space and resources, and one competition strategy is to produce a bacteriocin (antimicrobial peptide or protein) to attack other bacteria and an immunity protein to protect against self-destruction. We analysed a collection of 336 diverse pneumococcal genomes dating from 1916 onwards, identified bacteriocin cassettes, detailed their genetic composition and sequence diversity, and evaluated the data in the context of the pneumococcal population structure. Results We found that all genomes maintained a blp bacteriocin cassette and we identified several novel blp cassettes and genes. The composition of the ‘bacteriocin/immunity region’ of the blp cassette was highly variable: one cassette possessed six bacteriocin genes and eight putative immunity genes, whereas another cassette had only one of each. Both widely-distributed and highly clonal blp cassettes were identified. Most surprisingly, one-third of pneumococcal genomes also possessed a cassette encoding a novel circular bacteriocin that we called pneumocyclicin, which shared a similar genetic organisation to well-characterised circular bacteriocin cassettes in other bacterial species. Pneumocyclicin cassettes were mainly of one genetic cluster and largely found among seven major pneumococcal clonal complexes. Conclusions These detailed genomic analyses revealed a novel pneumocyclicin cassette and a wide variety of blp bacteriocin cassettes, suggesting that competition in the nasopharynx is a complex biological phenomenon. Electronic supplementary material The online version of this article (doi:10.1186/s12864-015-1729-4) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Carlijn Bogaardt
- Nuffield Department of Medicine, Peter Medawar Building for Pathogen Research, University of Oxford, Oxford, United Kingdom.
| | - Andries J van Tonder
- Nuffield Department of Medicine, Peter Medawar Building for Pathogen Research, University of Oxford, Oxford, United Kingdom.
| | - Angela B Brueggemann
- Nuffield Department of Medicine, Peter Medawar Building for Pathogen Research, University of Oxford, Oxford, United Kingdom.
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19
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Cebrián R, Martínez-Bueno M, Valdivia E, Albert A, Maqueda M, Sánchez-Barrena MJ. The bacteriocin AS-48 requires dimer dissociation followed by hydrophobic interactions with the membrane for antibacterial activity. J Struct Biol 2015; 190:162-72. [PMID: 25816760 DOI: 10.1016/j.jsb.2015.03.006] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2014] [Revised: 03/04/2015] [Accepted: 03/18/2015] [Indexed: 01/15/2023]
Abstract
The molecular mechanism underlining the antibacterial activity of the bacteriocin AS-48 is not known, and two different and opposite alternatives have been proposed. Available data suggested that the interaction of positively charged amino acids of AS-48 with the membrane would produce membrane destabilization and disruption. Alternatively, it has been proposed that AS-48 activity could rely on the effective insertion of the bacteriocin into the membrane. The biological and structural properties of the AS-48G13K/L40K double mutant were investigated to shed light on this subject. Compared with the wild type, the mutant protein suffered an important reduction in the antibacterial activity. Biochemical and structural studies of AS-48G13K/L40K mutant suggest the basis of its decreased antimicrobial activity. Lipid cosedimentation assays showed that the membrane affinity of AS-48G13K/L40K is 12-fold lower than that observed for the wild type. L40K mutation is responsible for this reduced membrane affinity and thus, hydrophobic interactions are involved in membrane association. Furthermore, the high-resolution crystal structure of AS-48G13K/L40K, together with the study of its dimeric character in solution showed that G13K stabilizes the inactive water-soluble dimer, which displays a reduced dipole moment. Our data suggest that the cumulative effect of these three affected properties reduces AS-48 activity, and point out that the bactericidal effect is achieved by the electrostatically driven approach of the inactive water-soluble dimer towards the membrane, followed by the dissociation and insertion of the protein into the lipid bilayer.
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Affiliation(s)
- Rubén Cebrián
- Departamento de Microbiología, Facultad de Ciencias, Universidad de Granada, Spain
| | | | - Eva Valdivia
- Departamento de Microbiología, Facultad de Ciencias, Universidad de Granada, Spain
| | - Armando Albert
- Departamento de Cristalografía y Biología Estructural, Instituto de Química Física "Rocasolano", Consejo Superior de Investigaciones Científicas, Madrid, Spain
| | - Mercedes Maqueda
- Departamento de Microbiología, Facultad de Ciencias, Universidad de Granada, Spain
| | - María José Sánchez-Barrena
- Departamento de Cristalografía y Biología Estructural, Instituto de Química Física "Rocasolano", Consejo Superior de Investigaciones Científicas, Madrid, Spain.
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20
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Nawrocki KL, Crispell EK, McBride SM. Antimicrobial Peptide Resistance Mechanisms of Gram-Positive Bacteria. Antibiotics (Basel) 2014; 3:461-92. [PMID: 25419466 PMCID: PMC4239024 DOI: 10.3390/antibiotics3040461] [Citation(s) in RCA: 78] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2014] [Revised: 09/25/2014] [Accepted: 09/28/2014] [Indexed: 01/09/2023] Open
Abstract
Antimicrobial peptides, or AMPs, play a significant role in many environments as a tool to remove competing organisms. In response, many bacteria have evolved mechanisms to resist these peptides and prevent AMP-mediated killing. The development of AMP resistance mechanisms is driven by direct competition between bacterial species, as well as host and pathogen interactions. Akin to the number of different AMPs found in nature, resistance mechanisms that have evolved are just as varied and may confer broad-range resistance or specific resistance to AMPs. Specific mechanisms of AMP resistance prevent AMP-mediated killing against a single type of AMP, while broad resistance mechanisms often lead to a global change in the bacterial cell surface and protect the bacterium from a large group of AMPs that have similar characteristics. AMP resistance mechanisms can be found in many species of bacteria and can provide a competitive edge against other bacterial species or a host immune response. Gram-positive bacteria are one of the largest AMP producing groups, but characterization of Gram-positive AMP resistance mechanisms lags behind that of Gram-negative species. In this review we present a summary of the AMP resistance mechanisms that have been identified and characterized in Gram-positive bacteria. Understanding the mechanisms of AMP resistance in Gram-positive species can provide guidelines in developing and applying AMPs as therapeutics, and offer insight into the role of resistance in bacterial pathogenesis.
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Affiliation(s)
- Kathryn L Nawrocki
- Department of Microbiology and Immunology, Emory University School of Medicine, 1510 Clifton Rd, Atlanta, GA 30322, USA; (K.L.N.); (E.K.C.)
| | - Emily K Crispell
- Department of Microbiology and Immunology, Emory University School of Medicine, 1510 Clifton Rd, Atlanta, GA 30322, USA; (K.L.N.); (E.K.C.)
| | - Shonna M McBride
- Department of Microbiology and Immunology, Emory University School of Medicine, 1510 Clifton Rd, Atlanta, GA 30322, USA; (K.L.N.); (E.K.C.)
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21
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Circular bacteriocins: biosynthesis and mode of action. Appl Environ Microbiol 2014; 80:6854-62. [PMID: 25172850 DOI: 10.1128/aem.02284-14] [Citation(s) in RCA: 86] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Circular bacteriocins are a group of N-to-C-terminally linked antimicrobial peptides, produced by Gram-positive bacteria of the phylum Firmicutes. Circular bacteriocins generally exhibit broad-spectrum antimicrobial activity, including against common food-borne pathogens, such as Clostridium and Listeria spp. These peptides are further known for their high pH and thermal stability, as well as for resistance to many proteolytic enzymes, properties which make this group of bacteriocins highly promising for potential industrial applications and their biosynthesis of particular interest as a possible model system for the synthesis of highly stable bioactive peptides. In this review, we summarize the current knowledge on this group of bacteriocins, with emphasis on the recent progress in understanding circular bacteriocin genetics, biosynthesis, and mode of action; in addition, we highlight the current challenges and future perspectives for the application of these peptides.
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22
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Potter A, Ceotto H, Coelho MLV, Guimarães AJ, Bastos MDCDF. The gene cluster of aureocyclicin 4185: the first cyclic bacteriocin of Staphylococcus aureus. Microbiology (Reading) 2014; 160:917-928. [DOI: 10.1099/mic.0.075689-0] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Staphylococcus aureus 4185 was previously shown to produce at least two bacteriocins. One of them is encoded by pRJ101. To detect the bacteriocin-encoding gene cluster, an ~9160 kb region of pRJ101 was sequenced. In silico analyses identified 10 genes (aclX, aclB, aclI, aclT, aclC, aclD, aclA, aclF, aclG and aclH) that might be involved in the production of a novel cyclic bacteriocin named aureocyclicin 4185. The organization of these genes was quite similar to that of the gene cluster responsible for carnocyclin A production and immunity. Four putative proteins encoded by these genes (AclT, AclC, AclD and AclA) also exhibited similarity to proteins encoded by cyclic bacteriocin gene clusters. Mutants derived from insertion of Tn917-lac into aclC, aclF, aclH and aclX were affected in bacteriocin production and growth. AclX is a 205 aa putative protein not encoded by the gene clusters of other cyclic bacteriocins. AclX exhibits 50 % similarity to a permease and has five putative membrane-spanning domains. Transcription analyses suggested that aclX is part of the aureocyclicin 4185 gene cluster, encoding a protein required for bacteriocin production. The aclA gene is the structural gene of aureocyclicin 4185, which shows 65 % similarity to garvicin ML. AclA is proposed to be cleaved off, generating a mature peptide with a predicted M
r of 5607 Da (60 aa). By homology modelling, AclA presents four α-helices, like carnocyclin A. AclA could not be found at detectable levels in the culture supernatant of a strain carrying only pRJ101. To our knowledge, this is the first report of a cyclic bacteriocin gene cluster in the genus Staphylococcus.
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Affiliation(s)
- Amina Potter
- Departamento de Microbiologia Geral, Instituto de Microbiologia Paulo de Góes, UFRJ, Rio de Janeiro, Brazil
| | - Hilana Ceotto
- Instituto Federal de Educação Tecnológica do Estado do Rio de Janeiro, IFRJ, Rio de Janeiro, Brazil
- Departamento de Microbiologia Geral, Instituto de Microbiologia Paulo de Góes, UFRJ, Rio de Janeiro, Brazil
| | - Marcus Lívio Varella Coelho
- Instituto Nacional da Propriedade Industrial, INPI, Rio de Janeiro, Brazil
- Departamento de Microbiologia Geral, Instituto de Microbiologia Paulo de Góes, UFRJ, Rio de Janeiro, Brazil
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23
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Cebrián R, Rodríguez-Ruano S, Martínez-Bueno M, Valdivia E, Maqueda M, Montalbán-López M. Analysis of the promoters involved in enterocin AS-48 expression. PLoS One 2014; 9:e90603. [PMID: 24594763 PMCID: PMC3942455 DOI: 10.1371/journal.pone.0090603] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2013] [Accepted: 01/31/2014] [Indexed: 11/17/2022] Open
Abstract
The enterocin AS-48 is the best characterized antibacterial circular protein in prokaryotes. It is a hydrophobic and cationic bacteriocin, which is ribosomally synthesized by enterococcal cells and post-translationally cyclized by a head-to-tail peptide bond. The production of and immunity towards AS-48 depend upon the coordinated expression of ten genes organized in two operons, as-48ABC (where genes encoding enzymes with processing, secretion, and immunity functions are adjacent to the structural as-48A gene) and as-48C1DD1EFGH. The current study describes the identification of the promoters involved in AS-48 expression. Seven putative promoters have been here amplified, and separately inserted into the promoter-probe vector pTLR1, to create transcriptional fusions with the mCherry gene used as a reporter. The activity of these promoter regions was assessed measuring the expression of the fluorescent mCherry protein using the constitutive pneumococcal promoter PX as a reference. Our results revealed that only three promoters PA, P2(2) and PD1 were recognized in Enterococcus faecalis, Lactococcus lactis and Escherichia coli, in the conditions tested. The maximal fluorescence was obtained with PX in all the strains, followed by the P2(2) promoter, which level of fluorescence was 2-fold compared to PA and 4-fold compared to PD1. Analysis of putative factors influencing the promoter activity in single and double transformants in E. faecalis JH2-2 demonstrated that, in general, a better expression was achieved in presence of pAM401-81. In addition, the P2(2) promoter could be regulated in a negative fashion by genes existing in the native pMB-2 plasmid other than those of the as-48 cluster, while the pH seems to affect differently the as-48 promoter expression.
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Affiliation(s)
- Rubén Cebrián
- Departamento de Microbiología, Facultad de Ciencias, Universidad de Granada, Granada, Spain
| | - Sonia Rodríguez-Ruano
- Departamento de Microbiología, Facultad de Ciencias, Universidad de Granada, Granada, Spain
| | - Manuel Martínez-Bueno
- Departamento de Microbiología, Facultad de Ciencias, Universidad de Granada, Granada, Spain
| | - Eva Valdivia
- Departamento de Microbiología, Facultad de Ciencias, Universidad de Granada, Granada, Spain
| | - Mercedes Maqueda
- Departamento de Microbiología, Facultad de Ciencias, Universidad de Granada, Granada, Spain
| | - Manuel Montalbán-López
- Departamento de Microbiología, Facultad de Ciencias, Universidad de Granada, Granada, Spain
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24
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Functional genetic analysis of the GarML gene cluster in Lactococcus garvieae DCC43 gives new insights into circular bacteriocin biosynthesis. J Bacteriol 2013; 196:911-9. [PMID: 24336941 DOI: 10.1128/jb.01115-13] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Garvicin ML (GarML) is a circular bacteriocin produced by Lactococcus garvieae DCC43. The recently published draft genome of this strain allowed determination of the genetic background for bacteriocin production. Bioinformatic analysis identified a gene cluster consisting of nine open reading frames likely involved in the production of and immunity to GarML. The garA gene encodes the bacteriocin precursor, garX a large transmembrane protein, garBCDE a putative immunity protein (garB) followed by an ATPase and two transmembrane proteins, and garFGH a putative ABC transporter complex. Functional genetic analysis revealed that deletion of garFGH had no effect on sensitivity to or production of GarML. In contrast, deletion of garBCDE or inactivation of garX resulted in high-level sensitivity to GarML and completely abolished production of active bacteriocin. Mass spectrometry of culture supernatants revealed that wild-type cultures contained the mature circular form as well as the linear forms of the bacteriocin, both with and without the three-amino-acid leader sequence, while bacteriocin-negative mutants contained only the linear forms. These results indicate that cleavage of the leader peptide precedes circularization and is likely performed by a functional entity separate from the GarML gene cluster. To our knowledge, this is the first conclusive evidence for these processes being separated in time. Loss of immunity and antimicrobial activity in addition to our inability to detect the circular bacteriocin in the ΔgarBCDE and garX::pCG47 mutants demonstrate that both these units are indispensable for GarML biosynthesis as well as immunity. Furthermore, the results indicate that these genes are implicated in the circularization of the bacteriocin and that their functions are probably interlinked.
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Mu F, Masuda Y, Zendo T, Ono H, Kitagawa H, Ito H, Nakayama J, Sonomoto K. Biological function of a DUF95 superfamily protein involved in the biosynthesis of a circular bacteriocin, leucocyclicin Q. J Biosci Bioeng 2013; 117:158-164. [PMID: 23906710 DOI: 10.1016/j.jbiosc.2013.06.023] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2013] [Revised: 06/27/2013] [Accepted: 06/28/2013] [Indexed: 10/26/2022]
Abstract
Biological functions of a DUF95 superfamily protein in the biosynthesis gene cluster of a novel circular bacteriocin, leucocyclicin Q (LcyQ), were characterized in this paper. Sequence analysis and database search of the regions flanking the LcyQ structural gene lcyQ revealed four open reading frames (lcyR, lcyB, lcyC, and lcyD) related to bacteriocin biosynthesis. LcyD shares some similarity to the DUF95 superfamily proteins, often found in the biosynthetic gene clusters of circular bacteriocins. Mass spectrometry analysis showed accumulation of active mature LcyQ inside lcyD knockout cells. Heterologous expression of lcyD demonstrated that it confers robust immunity against LcyQ. Peptide release/binding assay revealed that the immunity could be attributed to the secretion of LcyQ to the cell exterior. Thus, the DUF95 superfamily protein has a dual function in the biosynthesis of LcyQ, as an immunity-associated transporter and as a secretion-aiding agent. Accumulation of mature LcyQ inside the cell in lcyD knockout strains, further implied that cyclization occurs within the cell. To the best of our knowledge, this is the first report on LcyQ cyclization inside the cell and the dual role of a DUF95 superfamily protein in circular bacteriocin biosynthesis.
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Affiliation(s)
- Fuqin Mu
- Laboratory of Microbial Technology, Division of Applied Molecular Microbiology and Biomass Chemistry, Department of Bioscience and Biotechnology, Faculty of Agriculture, Graduate School, Kyushu University, 6-10-1 Hakozaki, Higashi-ku, Fukuoka 812-8581, Japan
| | - Yoshimitsu Masuda
- Laboratory of Microbial Technology, Division of Applied Molecular Microbiology and Biomass Chemistry, Department of Bioscience and Biotechnology, Faculty of Agriculture, Graduate School, Kyushu University, 6-10-1 Hakozaki, Higashi-ku, Fukuoka 812-8581, Japan
| | - Takeshi Zendo
- Laboratory of Microbial Technology, Division of Applied Molecular Microbiology and Biomass Chemistry, Department of Bioscience and Biotechnology, Faculty of Agriculture, Graduate School, Kyushu University, 6-10-1 Hakozaki, Higashi-ku, Fukuoka 812-8581, Japan
| | - Hiroshi Ono
- R&D Laboratories, Tokai Pickling Co. Ltd., 78-1 Mukaigo, Mukokusamacho, Toyohashi 441-8142, Japan
| | - Hiroshi Kitagawa
- R&D Laboratories, Tokai Pickling Co. Ltd., 78-1 Mukaigo, Mukokusamacho, Toyohashi 441-8142, Japan
| | - Haruo Ito
- R&D Laboratories, Tokai Pickling Co. Ltd., 78-1 Mukaigo, Mukokusamacho, Toyohashi 441-8142, Japan
| | - Jiro Nakayama
- Laboratory of Microbial Technology, Division of Applied Molecular Microbiology and Biomass Chemistry, Department of Bioscience and Biotechnology, Faculty of Agriculture, Graduate School, Kyushu University, 6-10-1 Hakozaki, Higashi-ku, Fukuoka 812-8581, Japan
| | - Kenji Sonomoto
- Laboratory of Microbial Technology, Division of Applied Molecular Microbiology and Biomass Chemistry, Department of Bioscience and Biotechnology, Faculty of Agriculture, Graduate School, Kyushu University, 6-10-1 Hakozaki, Higashi-ku, Fukuoka 812-8581, Japan; Laboratory of Functional Food Design, Department of Functional Metabolic Design, Bio-Architecture Center, Kyushu University, 6-10-1 Hakozaki, Higashi-ku, Fukuoka 812-8581, Japan.
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26
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Bifunctional gene cluster lnqBCDEF mediates bacteriocin production and immunity with differential genetic requirements. Appl Environ Microbiol 2013; 79:2446-9. [PMID: 23335763 DOI: 10.1128/aem.03783-12] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
A comprehensive gene disruption of lacticin Q biosynthetic cluster lnqQBCDEF was carried out. The results demonstrated the necessity of the complete set of lnqQBCDEF for lacticin Q production, whereas immunity was flexible, with LnqEF (ABC transporter) being essential for and LnqBCD partially contributing to immunity.
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27
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van Belkum MJ, Vederas JC. The ABC Transporter CclEFGH Facilitates the Production of the Circular Bacteriocin Carnocyclin A. Probiotics Antimicrob Proteins 2012; 4:273-8. [DOI: 10.1007/s12602-012-9112-0] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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Masuda Y, Zendo T, Sonomoto K. New type non-lantibiotic bacteriocins: circular and leaderless bacteriocins. Benef Microbes 2012; 3:3-12. [PMID: 22348904 DOI: 10.3920/bm2011.0047] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Bacteriocins are antimicrobial peptides that are ribosomally synthesised by bacteria. Bacteriocins produced by Gram-positive bacteria, including lactic acid bacteria, are under focus as the next generation of safe natural biopreservatives and as therapeutic alternatives to antibiotics. Recently, two novel types of non-lantibiotic class II bacteriocins have been reported with unique characteristics in their structure and biosynthesis mechanism. One is a circular bacteriocin that contains a head-to-tail structure in the mature form, and the other is a leaderless bacteriocin without an N-terminal extension in the precursor peptide. A circular structure can provide the peptide with remarkable stability against various stresses; indeed, circular bacteriocins are known to possess higher stability than general linear bacteriocins. Leaderless bacteriocins are distinct from general bacteriocins, because they do not contain N-terminal leader sequences, which are responsible for the recognition process during secretion and for inactivation of bacteriocins inside producer cells. Leaderless bacteriocins do not require any post-translational processing for activity. These two novel types of bacteriocins are promising antimicrobial compounds, and their biosynthetic mechanisms are expected to be applied in synthetic biology to design new peptides and for new mass production systems. However, many questions remain about their biosynthesis. In this review, we introduce recent studies on these types of bacteriocins and their potential to open a new world of antimicrobial peptides.
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Affiliation(s)
- Y Masuda
- Laboratory of Microbial Technology, Division of Applied Molecular Microbiology and Biomass Chemistry, Department of Bioscience and Biotechnology, Faculty of Agriculture, Graduate School, Kyushu University, Hakozaki, Higashi-ku, Fukuoka, Japan
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29
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Hassan M, Kjos M, Nes I, Diep D, Lotfipour F. Natural antimicrobial peptides from bacteria: characteristics and potential applications to fight against antibiotic resistance. J Appl Microbiol 2012; 113:723-36. [DOI: 10.1111/j.1365-2672.2012.05338.x] [Citation(s) in RCA: 254] [Impact Index Per Article: 21.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2012] [Revised: 04/18/2012] [Accepted: 05/02/2012] [Indexed: 12/22/2022]
Affiliation(s)
| | - M. Kjos
- Departments of Chemistry, Biotechnology and Food Science; Norwegian University of Life Sciences; Aas; Norway
| | - I.F. Nes
- Departments of Chemistry, Biotechnology and Food Science; Norwegian University of Life Sciences; Aas; Norway
| | - D.B. Diep
- Departments of Chemistry, Biotechnology and Food Science; Norwegian University of Life Sciences; Aas; Norway
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30
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Kjos M, Borrero J, Opsata M, Birri DJ, Holo H, Cintas LM, Snipen L, Hernández PE, Nes IF, Diep DB. Target recognition, resistance, immunity and genome mining of class II bacteriocins from Gram-positive bacteria. Microbiology (Reading) 2011; 157:3256-3267. [DOI: 10.1099/mic.0.052571-0] [Citation(s) in RCA: 88] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
Due to their very potent antimicrobial activity against diverse food-spoiling bacteria and pathogens and their favourable biochemical properties, peptide bacteriocins from Gram-positive bacteria have long been considered promising for applications in food preservation or medical treatment. To take advantage of bacteriocins in different applications, it is crucial to have detailed knowledge on the molecular mechanisms by which these peptides recognize and kill target cells, how producer cells protect themselves from their own bacteriocin (self-immunity) and how target cells may develop resistance. In this review we discuss some important recent progress in these areas for the non-lantibiotic (class II) bacteriocins. We also discuss some examples of how the current wealth of genome sequences provides an invaluable source in the search for novel class II bacteriocins.
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Affiliation(s)
- Morten Kjos
- Department of Chemistry, Biotechnology and Food Science, Norwegian University of Life Sciences, Ås, Norway
| | - Juan Borrero
- Departamento de Nutrición, Bromatología y Tecnología de los Alimentos, Facultad de Veterinaria, Universidad Complutense de Madrid (UCM), 28040 Madrid, Spain
| | - Mona Opsata
- Department of Chemistry, Biotechnology and Food Science, Norwegian University of Life Sciences, Ås, Norway
| | - Dagim J. Birri
- Department of Chemistry, Biotechnology and Food Science, Norwegian University of Life Sciences, Ås, Norway
| | - Helge Holo
- Department of Chemistry, Biotechnology and Food Science, Norwegian University of Life Sciences, Ås, Norway
| | - Luis M. Cintas
- Departamento de Nutrición, Bromatología y Tecnología de los Alimentos, Facultad de Veterinaria, Universidad Complutense de Madrid (UCM), 28040 Madrid, Spain
| | - Lars Snipen
- Department of Chemistry, Biotechnology and Food Science, Norwegian University of Life Sciences, Ås, Norway
| | - Pablo E. Hernández
- Departamento de Nutrición, Bromatología y Tecnología de los Alimentos, Facultad de Veterinaria, Universidad Complutense de Madrid (UCM), 28040 Madrid, Spain
| | - Ingolf F. Nes
- Department of Chemistry, Biotechnology and Food Science, Norwegian University of Life Sciences, Ås, Norway
| | - Dzung B. Diep
- Department of Chemistry, Biotechnology and Food Science, Norwegian University of Life Sciences, Ås, Norway
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Identification and characterization of leucocyclicin Q, a novel cyclic bacteriocin produced by Leuconostoc mesenteroides TK41401. Appl Environ Microbiol 2011; 77:8164-70. [PMID: 21948835 DOI: 10.1128/aem.06348-11] [Citation(s) in RCA: 71] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The culture supernatant of Leuconostoc mesenteroides TK41401, isolated from Japanese pickles, possessed antimicrobial activity against broad range of a bacterial genera and particularly strong activity against Bacillus coagulans, the major contaminant of pickles. An antimicrobial peptide was purified in three chromatographic steps, and its molecular mass was determined to be 6,115.59 Da by electrospray ionization time-of-flight mass spectrometry (ESI-TOF MS). The primary structure of this peptide was determined by amino acid and DNA sequencing, and these analyses revealed that it was translated as a 63-residue precursor. This precursor showed high similarity to the precursor of lactocyclicin Q, a cyclic bacteriocin produced by Lactococcus sp. strain QU 12. The molecular weight calculated after cyclization, which was presumed to involve the same process as in lactocyclicin Q (between L3 and W63), agreed with that estimated by ESI-TOF MS. This peptide was proved to be a novel cyclic bacteriocin, and it was termed leucocyclicin Q. The antimicrobial spectrum of this bacteriocin clearly differed from that of lactocyclicin Q, even though their primary structures were quite similar. This is the first report of a cyclic bacteriocin produced by a strain of the genus Leuconostoc.
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32
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van Belkum MJ, Martin-Visscher LA, Vederas JC. Structure and genetics of circular bacteriocins. Trends Microbiol 2011; 19:411-8. [PMID: 21664137 DOI: 10.1016/j.tim.2011.04.004] [Citation(s) in RCA: 86] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2011] [Revised: 04/14/2011] [Accepted: 04/29/2011] [Indexed: 10/18/2022]
Abstract
Circular bacteriocins are antimicrobial peptides produced by a variety of Gram-positive bacteria. They are part of a growing family of ribosomally synthesized peptides with a head-to-tail cyclization of their backbone that are found in mammals, plants, fungi and bacteria and are exceptionally stable. These bacteriocins permeabilize the membrane of sensitive bacteria, causing loss of ions and dissipation of the membrane potential. Most circular bacteriocins probably adopt a common 3D structure consisting of four or five α-helices encompassing a hydrophobic core. This review compares the various structures, as well as the gene clusters that encode circular bacteriocins, and discusses the biogenesis of this unique class of bacteriocins.
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Insights into the functionality of the putative residues involved in enterocin AS-48 maturation. Appl Environ Microbiol 2010; 76:7268-76. [PMID: 20833793 DOI: 10.1128/aem.01154-10] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
AS-48 is a 70-residue, α-helical, cationic bacteriocin produced by Enterococcus faecalis and is very singular in its circular structure and its broad antibacterial spectrum. The AS-48 preprotein consists of an N-terminal signal peptide (SP) (35 residues) followed by a proprotein moiety that undergoes posttranslational modifications to yield the mature and active circular protein. For the study of the specificity of the region of AS-48 that is responsible for maturation, three single mutants have been generated by site-directed mutagenesis in the as-48A structural gene. The substitutions were made just in the residues that are thought to constitute a recognition site for the SP cleavage enzyme (His-1, Met1) and in those involved in circularization (Met1, Trp70). Each derivative was expressed in the enterococcal JH2-2 strain containing the necessary native biosynthetic machinery for enterocin production. The importance of these derivatives in AS-48 processing has been evaluated on the basis of the production and structural characterization of the corresponding derivatives. Notably, only two of them (Trp70Ala and Met1Ala derivatives) could be purified in different forms and amounts and are characterized for their bactericidal activity and secondary structure. We could not detect any production of AS-48 in JH2-2(pAM401-81(His-1Ile)) by using the conventional chromatographic techniques, despite the high efficiency of the culture conditions applied to produce this enterocin. Our results underline the different important roles of the mutated residues in (i) the elimination of the SP, (ii) the production levels and antibacterial activity of the mature proteins, and (iii) protein circularization. Moreover, our findings suggest that His-1 is critically involved in cleavage site recognition, its substitution being responsible for the blockage of processing, thereby hampering the production of the specific protein in the cellular culture supernatant.
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34
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Conlan BF, Gillon AD, Craik DJ, Anderson MA. Circular proteins and mechanisms of cyclization. Biopolymers 2010; 94:573-83. [DOI: 10.1002/bip.21422] [Citation(s) in RCA: 69] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
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35
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Ananou S, Muñoz A, Martínez-Bueno M, González-Tello P, Gálvez A, Maqueda M, Valdivia E. Evaluation of an enterocin AS-48 enriched bioactive powder obtained by spray drying. Food Microbiol 2009; 27:58-63. [PMID: 19913693 DOI: 10.1016/j.fm.2009.08.002] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2009] [Revised: 07/31/2009] [Accepted: 08/01/2009] [Indexed: 11/17/2022]
Abstract
Enterocin AS-48 is a cationic cyclic bacteriocin produced by Enterococcus faecalis with broad bactericidal activity. Currently we are assaying the efficacy of AS-48 as biopreservative in foods. In this work we have applied the spray drying process to different AS-48 liquid samples to obtain active dried preparations. We have also assayed different methods, heat, UV irradiation and filtration, to inactivate/remove the AS-48 producer cells from the samples. Best results were obtained for the sample from CM-25 cation exchange, for which it was also possible to completely eliminate/inactivate the producer cells by heat or UV irradiation without loss of activity. When added at 0.016% or 5% to Brain Heart Infusion broth or to skim milk, respectively, the AS-48 powder caused early and complete inactivation of Listeria monocytogenes. A partial inhibition of Staphylococcus aureus was achieved in broth and in skim milk supplemented with 2.5% and 10% AS-48 powder, respectively.
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Affiliation(s)
- S Ananou
- Departamento de Microbiología, Facultad de Ciencias, Universidad de Granada, Fuentenueva s/n, 19071 Granada, Spain
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36
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Ying W, Zhu R, Lu W, Gong L. A new strategy to apply Bacillus subtilis MA139 for the production of solid-state fermentation feed. Lett Appl Microbiol 2009; 49:229-34. [PMID: 19500243 DOI: 10.1111/j.1472-765x.2009.02647.x] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
AIM The study investigated the potential of using Bacillus subtilis MA139 in combination with Lactobacillus fermentum and Saccharomyces cerevisae to produce solid-state fermentation feed. METHODS AND RESULTS In a pure fermentation, B. subtilis MA139 was able to grow and synthesize antimicrobial substances at temperatures from 25 to 37 degrees C and at a pH from 5.0 to 9.0. Subsequently, B. subtilis MA139, Lact. fermentum and S. cerevisae were used as starter strains co-inoculated in unsterilized substrate (feed-grade soybean meal and wheat bran). Following 10 days of fermentation in a newly developed plastic bag equipped with a one-way valve, lactic acid bacteria and Bacillus became the predominant strains while S. cerevisae cells decreased slightly. Enterobacteriaceae (Escherichia coli K88 and Salmonella typhimurium) were not detected. CONCLUSIONS Use of B. subtilis MA139 as a starter strain co-inoculated with S. cerevisae and Lact. fermentum successfully controlled the growth of enterobacteriaceae. SIGNIFICANCE AND IMPACT OF THE STUDY This study provided a facile and low-cost way to produce solid-state fermentation feed.
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Affiliation(s)
- W Ying
- State Key Laboratory of Animal Nutrition, China Agricultural University, Beijing, China
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37
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Sobrino-Lopez A, Viedma-Martínez P, Abriouel H, Valdivia E, Gálvez A, Martin-Belloso O. The effect of adding antimicrobial peptides to milk inoculated with Staphylococcus aureus and processed by high-intensity pulsed-electric field. J Dairy Sci 2009; 92:2514-23. [PMID: 19447982 DOI: 10.3168/jds.2008-1996] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
The use of high-intensity pulsed-electric field (HIPEF) and antimicrobial substances of natural origin, such as enterocin AS-48 (AS-48), nisin, and lysozyme, are among the most important nonthermal preservation methods. Thus, the purpose of this study was to evaluate the combined effect on milk inoculated with Staphylococcus aureus of the addition of AS-48 with nisin or lysozyme, or both, together with the use of HIPEF. Synergy was observed in the reduction of Staph. aureus counts with the following combination methods: i) addition of AS-48 and nisin, ii) addition of AS-48 plus use of HIPEF, and iii) addition of AS-48 and nisin plus use of HIPEF. Specifically, when 28 arbitrary units/mL of AS-48 and 20 IU/mL of nisin were added to the milk, and it was treated with HIPEF for 800 mus, over 6 log reductions were observed in the microorganism. In general, Staph. aureus inactivation was dependent on HIPEF treatment time, antimicrobial doses, and medium pH. During storage of the treated milk, survivor population was related to peptide concentration and temperature. Final cell viability was influenced by the sequence in which the treatments were applied: the addition of AS-48 or AS-48 and nisin was more effective before than after HIPEF treatment. The results obtained indicate that the combination of HIPEF and antimicrobials could be of great interest to the dairy industry, although it is necessary to study further the way in which the combined treatments act.
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Affiliation(s)
- A Sobrino-Lopez
- Department of Food Technology, University of Lleida, Avda. Alcalde Rovira Roure 191, 25198 Lleida, Spain
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38
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DNA sequencing and homologous expression of a small peptide conferring immunity to gassericin A, a circular bacteriocin produced by Lactobacillus gasseri LA39. Appl Environ Microbiol 2008; 75:1324-30. [PMID: 19114506 DOI: 10.1128/aem.02485-08] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Gassericin A, produced by Lactobacillus gasseri LA39, is a hydrophobic circular bacteriocin. The DNA region surrounding the gassericin A structural gene, gaaA, was sequenced, and seven open reading frames (ORFs) of 3.5 kbp (gaaBCADITE) were found with possible functions in gassericin A production, secretion, and immunity. The deduced products of the five consecutive ORFs gaaADITE have homology to those of genes involved in butyrivibriocin AR10 production, although the genetic arrangements are different in the two circular bacteriocin genes. GaaI is a small, positively charged hydrophobic peptide of 53 amino acids containing a putative transmembrane segment. Heterologous expression and homologous expression of GaaI in Lactococcus lactis subsp. cremoris MG1363 and L. gasseri JCM1131(T), respectively, were studied. GaaI-expressing strains exhibited at least sevenfold-higher resistance to gassericin A than corresponding control strains, indicating that gaaI encodes an immunity peptide for gassericin A. Comparison of GaaI to peptides with similar characteristics found in the circular bacteriocin gene loci is discussed.
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39
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Calvez S, Prevost H, Drider D. Relative expression of genes involved in the resistance/sensitivity of Enterococcus faecalis JH2-2 to recombinant divercin RV41. Biotechnol Lett 2008; 30:1795-800. [PMID: 18563584 DOI: 10.1007/s10529-008-9752-z] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2008] [Revised: 05/06/2008] [Accepted: 05/08/2008] [Indexed: 11/30/2022]
Abstract
The relative expression of mptABCD operon, glpQ, pde, rpoN, mptR and gap-1 was studied by reverse transcription combined with the real time polymerase chain reaction to understand the role of each gene in resistance/sensitivity of Enterococcus faecalis to class IIa bacteriocins such as recombinant divercin V41 (DvnRV41). Comparative critical threshold methods in presence or absence of DvnRV41 were then used to determine the level of expression of each gene cited above. In the presence of DvnRV41, the rpoN and glpQ genes were down-regulated, mptR, mptC, gap-1 and pde genes were up-regulated, whilst expression of mptB and mptD genes remained unmodified.
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Affiliation(s)
- Ségolène Calvez
- Laboratoire de Microbiologie, ENITIAA, Rue de la Géraudière, BP 82225, 44322 Nantes Cedex 3, France
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40
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Sánchez-Hidalgo M, Martínez-Bueno M, Fernández-Escamilla AM, Valdivia E, Serrano L, Maqueda M. Effect of replacing glutamic residues upon the biological activity and stability of the circular enterocin AS-48. J Antimicrob Chemother 2008; 61:1256-65. [DOI: 10.1093/jac/dkn126] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
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41
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Maqueda M, Sánchez-Hidalgo M, Fernández M, Montalbán-López M, Valdivia E, Martínez-Bueno M. Genetic features of circular bacteriocins produced by Gram-positive bacteria. FEMS Microbiol Rev 2008; 32:2-22. [DOI: 10.1111/j.1574-6976.2007.00087.x] [Citation(s) in RCA: 123] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022] Open
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42
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Wirawan RE, Swanson KM, Kleffmann T, Jack RW, Tagg JR. Uberolysin: a novel cyclic bacteriocin produced by Streptococcus uberis. MICROBIOLOGY-SGM 2007; 153:1619-1630. [PMID: 17464077 DOI: 10.1099/mic.0.2006/005967-0] [Citation(s) in RCA: 81] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Streptococcus uberis is commonly found in the environment and in association with various bovine body sites and is a major cause of bovine mastitis. Moreover, S. uberis is known to produce a variety of bacteriocin-like inhibitory substances, antimicrobial agents that generally inhibit closely related bacterial species. In this respect, S. uberis strain 42 has previously been shown to produce a novel nisin variant named nisin U. This paper reports that, in addition to nisin U, S. uberis strain 42 produces a second bacteriocin that induces the lysis of metabolically active, susceptible target bacteria and which has therefore been named uberolysin. Isolation of the native active antimicrobial agent revealed that uberolysin is a 7048 Da peptide that is refractory to sequence analysis by Edman degradation. Transposon mutagenesis was used to generate a uberolysin-negative mutant of S. uberis 42 and sequencing of DNA flanking the insertion site revealed, in addition to the structural gene (ublA), several open reading frames likely to be involved in post-translational modification, transport and producer self-protection (immunity), and possibly in regulation of the biosynthetic gene cluster. In addition, a pair of direct repeats that may be involved in bacteriocin acquisition were identified; indeed, ublA could be identified in 18 % of tested S. uberis strains. Enzymic hydrolysis of uberolysin was used to confirm that ublA does indeed encode the precursor of uberolysin, that an unusually short leader sequence of only six amino acids is cleaved during processing of the mature peptide and that uberolysin is post-translationally covalently modified to form a head-to-tail monocycle. Thus, uberolysin is a unique cyclic bacteriocin, belonging to the same family of bacteriocins as enterocin AS-48 and circularin A.
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Affiliation(s)
- Ruth E Wirawan
- Department of Microbiology and Immunology, Otago School of Medical Sciences, University of Otago, PO Box 56, Dunedin, New Zealand
| | - Kara M Swanson
- Department of Microbiology and Immunology, Otago School of Medical Sciences, University of Otago, PO Box 56, Dunedin, New Zealand
| | - Torsten Kleffmann
- Centre for Protein Research (Department of Biochemistry), Otago School of Medical Sciences, University of Otago, PO Box 56, Dunedin, New Zealand
| | - Ralph W Jack
- Department of Microbiology and Immunology, Otago School of Medical Sciences, University of Otago, PO Box 56, Dunedin, New Zealand
| | - John R Tagg
- Department of Microbiology and Immunology, Otago School of Medical Sciences, University of Otago, PO Box 56, Dunedin, New Zealand
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Processing of as-48ABC RNA in AS-48 enterocin production by Enterococcus faecalis. J Bacteriol 2007; 190:240-50. [PMID: 17981958 DOI: 10.1128/jb.01528-07] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Enterocin AS-48 production and immunity characters are encoded by 10 genes (as-48ABCC(1)DD(1)EFGH) of the pMB2 plasmid from the Enterococcus faecalis S-48 strain. Among these, as-48A, encoding the AS-48 peptide, and the as-48BC genes constitute a cluster required for AS-48 biogenesis and full immunity. In this study, the levels of expression of this cluster have been altered by insertion and site-directed mutagenesis as well as by expression coupled to trans complementation. Phenotypic studies of the mutants have indicated cotranscription of the three genes and revealed that the inactivation of as-48B prevents the production of AS-48, thus confirming its essentiality in AS-48 biogenesis. These studies have also supported the involvement of as-48C in enterocin immunity. In addition, they established that the intergenic region between the as-48A and as-48B genes is decisive for AS-48 expression, since a 3-bp substitution, which should disrupt a potential 47-nucleotide complex secondary structure, resulted in a hypoproducing phenotype. Transcriptional analyses of the E. faecalis wild-type and mutant strains supports the possibility that the as-48ABC genes are transcribed from the P(A) promoter located upstream of as-48A. Moreover, analysis and bioinformatic predictions of RNA folding indicate that as-48ABC mRNA is processed at the secondary structure located between as-48A and as-48B. Thus, synthesis of the AS-48 peptide appears to be controlled at the posttranscriptional level and is uncoupled from as-48BC translation. This mechanism of genetic regulation has not been previously described for the regulation of bacteriocin expression in enterococci.
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44
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Fernández M, Martínez-Bueno M, Martín MC, Valdivia E, Maqueda M. Heterologous expression of enterocin AS-48 in several strains of lactic acid bacteria. J Appl Microbiol 2007; 102:1350-61. [PMID: 17448170 DOI: 10.1111/j.1365-2672.2006.03194.x] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
AIMS Enterococcus faecalis produces a cationic and circular enterocin, AS-48, of 7149 Da, the genetic determinants of which are located within the pMB2 plasmid. We have compared enterocin AS-48 production by different enterococci species with that of other 'safe' lactic acid bacteris (LAB) (GRAS status) and looked into the subsequent application of this enterocin in food production. METHODS AND RESULTS In an effort to exploit this system for the heterologous expression of enterocin AS-48, a number of vectors containing the as-48 cluster were constructed and used to transform several LAB strains (genera Enterococcus, Lactococcus and Lactobacillus) CONCLUSION Heterologous production of enterocin AS-48 failed when bacteria other than those belonging to the genus Enterococcus were used as hosts, although expression of a partial level of resistance against AS-48 were always detected, ruling out the possibility of a lack of recognition of the enterococcal promoters. SIGNIFICANCE AND IMPACT OF THE STUDY Our results reveal the special capacity of species from the genus Enterococcus to produce AS-48, an enterocin that requires a post-transcriptional modification to generate a circular peptide with a wide range of inhibitory activity against pathogenic and spoilage bacteria. Preliminary experiments in foodstuffs using nonvirulent enterococci with interesting functional properties reveal the possibility of a biotechnological application of these transformants.
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Affiliation(s)
- M Fernández
- Departamento de Microbiología, Facultad de Ciencias, Universidad de Granada, Granada, Spain
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45
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Franz CMAP, van Belkum MJ, Holzapfel WH, Abriouel H, Gálvez A. Diversity of enterococcal bacteriocins and their grouping in a new classification scheme. FEMS Microbiol Rev 2007; 31:293-310. [PMID: 17298586 DOI: 10.1111/j.1574-6976.2007.00064.x] [Citation(s) in RCA: 273] [Impact Index Per Article: 16.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
Abstract
Enterococci are lactic acid bacteria of importance in food, public health and medical microbiology. Many strains produce bacteriocins, some of which have been well characterized. This review describes the structural and genetic characteristics of enterocins, the bacteriocins produced by enterococci. Some of these can be grouped with typical bacteriocins produced by lactic acid bacteria according to traditional classification, whereas others are atypical and structurally distinct from the general classes of bacteriocins. These atypical enterocins recently played an important role in and prompted reclassification of the class II bacteriocins into a new scheme. In this review, a more simplified classification scheme for enterocins based on amino acid sequence homologies is proposed. Enterocins are of interest for their diversity and potential for use as food biopreservatives. The emergence of multiple antibiotic-resistant enterococci among agents of nosocomial disease and the presence of virulence factors among food isolates requires a careful safety evaluation of isolates intended for potential biotechnical use. Nevertheless, enterococcal bacteriocins produced by heterologous hosts or added as cell-free preparations may still be attractive for application in food preservation.
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Affiliation(s)
- Charles M A P Franz
- Federal Research Centre for Nutrition and Food, Institute for Hygiene and Toxicology, Karlsruhe, Germany
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46
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Ruiz-Barba JL, Floriano B, Maldonado-Barragán A, Jiménez-Díaz R. Molecular analysis of the 21-kb bacteriocin-encoding plasmid pEF1 from Enterococcus faecium 6T1a. Plasmid 2006; 57:175-81. [PMID: 16893567 DOI: 10.1016/j.plasmid.2006.06.003] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2006] [Revised: 06/12/2006] [Accepted: 06/13/2006] [Indexed: 11/16/2022]
Abstract
The complete 21,344-bp DNA sequence of the bacteriocin-encoding plasmid pEF1 from Enterococcus faecium 6T1a was determined. Thirty-four putative open reading frames which could code for proteins longer than 42 amino acids were found. Those included the structural genes encoding for the previously described bacteriocins enterocin I and J (also named as enterocins L50A and L50B). After comparison to sequences in public databases, analysis of the gene organization of pEF1 suggests a modular structure with three different functional domains: the replication region, the bacteriocin region and the mobilization plus UV-resistance region. This genetic mosaic structure most probably evolved through recombination events promoted by transposable elements. The hypothesis that the bacteriocin cluster on pEF1 could act as a functional plasmid stabilization module in E. faecium 6T1a is discussed.
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Affiliation(s)
- José Luis Ruiz-Barba
- Departamento de Biotecnología de Alimentos, Instituto de la Grasa, Consejo Superior de Investigaciones Científicas, Avda. Padre Garcia Tejero, 4; Aptdo.1078, 41012 Sevilla, Spain.
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47
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Butcher BG, Helmann JD. Identification of Bacillus subtilis sigma-dependent genes that provide intrinsic resistance to antimicrobial compounds produced by Bacilli. Mol Microbiol 2006; 60:765-82. [PMID: 16629676 DOI: 10.1111/j.1365-2958.2006.05131.x] [Citation(s) in RCA: 149] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Bacillus subtilis produces many antibiotics of varying structures and specificity. Here we identify a prominent role for sigma(W), an extracytoplasmic function (ECF) sigma factor, in providing intrinsic resistance to antimicrobial compounds produced by other Bacilli. By using a panel of B. subtilis mutants disrupted for each of the 30 known sigma(W)-dependent operons we identified resistance genes for at least three different antimicrobial compounds. The ydbST and fosB genes contribute to resistance to antimicrobial compound(s) produced by B. amyloliquefaciens FZB42, the yqeZyqfAB operon provides resistance to the SPbeta prophage-encoded bacteriocin sublancin, and the yknWXYZ operon and yfhL provide resistance to the antimicrobial peptide SdpC. YfhL encodes a paralogue of SdpI, a membrane protein that provides immunity to SdpC. In competition experiments, we identify sigma(W) as a key factor in allowing B. subtilis to resist antibiotic killing and encroachment by competing strains. Together with the previous observation that sigma(W) provides inducible resistance against the Streptomyces antibiotic fosfomycin, these studies support the notion that sigma(W) controls an antibiosis regulon important in the microbial ecology of soil bacteria.
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Affiliation(s)
- Bronwyn G Butcher
- Department of Microbiology, Cornell University, Ithaca, NY 14853-8101, USA
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48
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Ellermeier CD, Losick R. Evidence for a novel protease governing regulated intramembrane proteolysis and resistance to antimicrobial peptides in Bacillus subtilis. Genes Dev 2006; 20:1911-22. [PMID: 16816000 PMCID: PMC1522089 DOI: 10.1101/gad.1440606] [Citation(s) in RCA: 93] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
Abstract
Evidence is presented that the activation of the RNA polymerase sigma factor sigma(W) in Bacillus subtilis by regulated intramembrane proteolysis is governed by a novel, membrane-embedded protease. The sigma(W) factor is activated by proteolytic destruction of the membrane-bound anti-sigma(W) factor RsiW in response to antimicrobial peptides and other agents that damage the cell envelope. RsiW is destroyed by successive proteolytic events known as Site-1 and Site-2 cleavage. Site-2 cleavage is mediated by a member of the SpoIVFB-S2P family of intramembrane-acting metalloproteases, but the protease responsible for Site-1 cleavage was unknown. We have identified a previously uncharacterized, multipass membrane protein called PrsW (annotated YpdC) that is both necessary and sufficient (when artificially produced in an unrelated host bacterium) for Site-1 cleavage of RsiW. PrsW is a member of a widespread family of membrane proteins that includes at least one previously known protease. We identify residues important for proteolysis and a cluster of acidic residues involved in sensing antimicrobial peptides and cell envelope stress.
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Affiliation(s)
- Craig D Ellermeier
- Department of Molecular and Cellular Biology, Harvard University, Cambridge, Massachusetts 02138, USA
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49
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Abstract
Bacteriocins are bacterially produced antimicrobial peptides with narrow or broad host ranges. Many bacteriocins are produced by food-grade lactic acid bacteria, a phenomenon which offers food scientists the possibility of directing or preventing the development of specific bacterial species in food. This can be particularly useful in preservation or food safety applications, but also has implications for the development of desirable flora in fermented food. In this sense, bacteriocins can be used to confer a rudimentary form of innate immunity to foodstuffs, helping processors extend their control over the food flora long after manufacture.
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Affiliation(s)
- Paul D Cotter
- Alimentary Pharmabiotic Centre, Microbiology Department, University College Cork, Cork, Ireland
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50
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Abriouel H, Lucas R, Ben Omar N, Valdivia E, Maqueda M, Martínez-Cañamero M, Gálvez A. Enterocin AS-48RJ: a variant of enterocin AS-48 chromosomally encoded by Enterococcus faecium RJ16 isolated from food. Syst Appl Microbiol 2005; 28:383-97. [PMID: 16094865 DOI: 10.1016/j.syapm.2005.01.007] [Citation(s) in RCA: 58] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Abstract
The bacteriocinogenic strain RJ16 isolated from goat cheese has been identified as Enterococcusfaecium by species-specific PCR, DNA-rRNA hybridization and rDNA sequencing. Purified bacteriocin from strain RJ16 is a carboxypeptidase A-resistant peptide with a molecular mass (7125 Da) very close to the cyclic peptide enterocin AS-48. Bacteriocin from strain RJ16 and AS-48 show identical antibacterial spectra, although the former is slightly less active on strains of Listeria monocytogenes and Bacillus cereus. Producer strains show cross-immunity. PCR amplification of total DNA from strain RJ16 with primers for the AS-48 structural gene and sequencing of the amplified fragment revealed an almost identical sequence (99.5%), except for a single mutation that predicts the change of Glu residue at position 20 of AS-48 to Val. Therefore, bacteriocin produced by E. faecium RJ16 should be considered a variant of AS-48, which we call AS-48RJ. PCR amplification revealed that strain RJ16 contains the complete as-48. gene cluster. Hybridization with probes for as-48 gene cluster revealed a chromosomal location of as-48 genes in strain RJ16, being the first example of a chromosomal location of this bacteriocin trait. Strain RJ16 produced enzymes of interest in food processing (esterase, esterase lipase and phytase activities), and did not decarboxylate amino acids precursors for biogenic amines. Strain RJ16 did not exhibit haemolytic or gelatinase activities, and PCR amplification revealed the lack of genes encoding for known virulence determinants (aggregation substance, collagen adhesin, enterococcal surface protein, endocarditis antigens, as well as haemolysin and gelatinase production). Strain RJ16 was resistant to ciprofloxacin (MIC > 2 mgl(-1)) and levofloxacin (MIC > 4 mgl(-1)) and showed intermediate resistance to nitrofurantoin and erythromycin, but was sensitive to ampicillin, penicillin, streptomycin, gentamicin, rifampicin, chloramphenicol, tetracycline, quinupristin/dalfopristin, vancomycin and teicoplanin. Altogether, results from this study suggest that this broad-spectrum bacteriocin-producing strain may have a potential use in food preservation.
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Affiliation(s)
- Hikmate Abriouel
- Area de Microbiología, Departamento de Ciencias de la Salud, Facultad de Ciencias Experimentales, Universidad de Jaén, 23071-Jaén, Spain
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