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Rodriguez-Sanchez AC, Gónzalez-Salazar LA, Rodriguez-Orduña L, Cumsille Á, Undabarrena A, Camara B, Sélem-Mojica N, Licona-Cassani C. Phylogenetic classification of natural product biosynthetic gene clusters based on regulatory mechanisms. Front Microbiol 2023; 14:1290473. [PMID: 38029100 PMCID: PMC10663231 DOI: 10.3389/fmicb.2023.1290473] [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: 09/07/2023] [Accepted: 10/23/2023] [Indexed: 12/01/2023] Open
Abstract
The natural products (NPs) biosynthetic gene clusters (BGCs) represent the adapting biochemical toolkit for microorganisms to thrive different microenvironments. Despite their high diversity, particularly at the genomic level, detecting them in a shake-flask is challenging and remains the primary obstacle limiting our access to valuable chemicals. Studying the molecular mechanisms that regulate BGC expression is crucial to design of artificial conditions that derive on their expression. Here, we propose a phylogenetic analysis of regulatory elements linked to biosynthesis gene clusters, to classify BGCs to regulatory mechanisms based on protein domain information. We utilized Hidden Markov Models from the Pfam database to retrieve regulatory elements, such as histidine kinases and transcription factors, from BGCs in the MIBiG database, focusing on actinobacterial strains from three distinct environments: oligotrophic basins, rainforests, and marine environments. Despite the environmental variations, our isolated microorganisms share similar regulatory mechanisms, suggesting the potential to activate new BGCs using activators known to affect previously characterized BGCs.
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Affiliation(s)
| | - Luz A. Gónzalez-Salazar
- Centro de Biotecnologia FEMSA, Escuela de Ingeniería y Ciencias, Tecnológico de Monterrey, Monterrey, Mexico
| | - Lorena Rodriguez-Orduña
- Centro de Biotecnologia FEMSA, Escuela de Ingeniería y Ciencias, Tecnológico de Monterrey, Monterrey, Mexico
| | - Ándres Cumsille
- Centro de Biotecnología Daniel Alkalay, Universidad Técnica Federico Santa María, Valparaíso, Chile
| | - Agustina Undabarrena
- Centro de Biotecnología Daniel Alkalay, Universidad Técnica Federico Santa María, Valparaíso, Chile
- The Novo Nordisk Foundation Center for Biosustainability, Technical University of Denmark, Lyngby, Denmark
| | - Beatriz Camara
- Centro de Biotecnología Daniel Alkalay, Universidad Técnica Federico Santa María, Valparaíso, Chile
| | | | - Cuauhtemoc Licona-Cassani
- Centro de Biotecnologia FEMSA, Escuela de Ingeniería y Ciencias, Tecnológico de Monterrey, Monterrey, Mexico
- Integrative Biology Unit, The Institute for Obesity Research, Tecnológico de Monterrey, Monterrey, Mexico
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Ongpipattanakul C, Desormeaux EK, DiCaprio A, van der Donk WA, Mitchell DA, Nair SK. Mechanism of Action of Ribosomally Synthesized and Post-Translationally Modified Peptides. Chem Rev 2022; 122:14722-14814. [PMID: 36049139 PMCID: PMC9897510 DOI: 10.1021/acs.chemrev.2c00210] [Citation(s) in RCA: 66] [Impact Index Per Article: 33.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Ribosomally synthesized and post-translationally modified peptides (RiPPs) are a natural product class that has undergone significant expansion due to the rapid growth in genome sequencing data and recognition that they are made by biosynthetic pathways that share many characteristic features. Their mode of actions cover a wide range of biological processes and include binding to membranes, receptors, enzymes, lipids, RNA, and metals as well as use as cofactors and signaling molecules. This review covers the currently known modes of action (MOA) of RiPPs. In turn, the mechanisms by which these molecules interact with their natural targets provide a rich set of molecular paradigms that can be used for the design or evolution of new or improved activities given the relative ease of engineering RiPPs. In this review, coverage is limited to RiPPs originating from bacteria.
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Affiliation(s)
- Chayanid Ongpipattanakul
- Department of Biochemistry, University of Illinois at Urbana-Champaign, 600 South Mathews Avenue, Urbana, Illinois 61801, USA
| | - Emily K. Desormeaux
- Department of Chemistry, University of Illinois at Urbana-Champaign, 600 South Mathews Avenue, Urbana, Illinois 61801, USA
| | - Adam DiCaprio
- Department of Chemistry, University of Illinois at Urbana-Champaign, 600 South Mathews Avenue, Urbana, Illinois 61801, USA
| | - Wilfred A. van der Donk
- Department of Biochemistry, University of Illinois at Urbana-Champaign, 600 South Mathews Avenue, Urbana, Illinois 61801, USA
- Department of Chemistry, University of Illinois at Urbana-Champaign, 600 South Mathews Avenue, Urbana, Illinois 61801, USA
- Department of Howard Hughes Medical Institute, University of Illinois at Urbana-Champaign, 600 South Mathews Avenue, Urbana, Illinois 61801, USA
- Departments of Carl R. Woese Institute for Genomic Biology, University of Illinois at Urbana-Champaign, 1206 West Gregory Drive, Urbana, Illinois 61801, USA
| | - Douglas A. Mitchell
- Department of Chemistry, University of Illinois at Urbana-Champaign, 600 South Mathews Avenue, Urbana, Illinois 61801, USA
- Department of Microbiology, University of Illinois at Urbana-Champaign, 600 South Mathews Avenue, Urbana, Illinois 61801, USA
- Departments of Carl R. Woese Institute for Genomic Biology, University of Illinois at Urbana-Champaign, 1206 West Gregory Drive, Urbana, Illinois 61801, USA
| | - Satish K. Nair
- Department of Biochemistry, University of Illinois at Urbana-Champaign, 600 South Mathews Avenue, Urbana, Illinois 61801, USA
- Departments of Carl R. Woese Institute for Genomic Biology, University of Illinois at Urbana-Champaign, 1206 West Gregory Drive, Urbana, Illinois 61801, USA
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Vogel V, Bauer R, Mauerer S, Schiffelholz N, Haupt C, Seibold GM, Fändrich M, Walther P, Spellerberg B. Angicin, a novel bacteriocin of Streptococcus anginosus. Sci Rep 2021; 11:24377. [PMID: 34934110 PMCID: PMC8692603 DOI: 10.1038/s41598-021-03797-5] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2021] [Accepted: 12/01/2021] [Indexed: 11/09/2022] Open
Abstract
As a conserved defense mechanism, many bacteria produce antimicrobial peptides, called bacteriocins, which provide a colonization advantage in a multispecies environment. Here the first bacteriocin of Streptococcus anginosus, designated Angicin, is described. S. anginosus is commonly described as a commensal, however it also possesses a high pathogenic potential. Therefore, understanding factors contributing to its host colonization and persistence are important. A radial diffusion assay was used to identify S. anginosus BSU 1211 as a potent bacteriocin producer. By genetic mutagenesis the background of bacteriocin production and the bacteriocin gene itself were identified. Synthetic Angicin shows high activity against closely related streptococci, listeria and vancomycin resistant enterococci. It has a fast mechanism of action and causes a membrane disruption in target cells. Angicin, present in cell free supernatant, is insensitive to changes in temperature from - 70 to 90 °C and pH values from 2 to 10, suggesting that it represents an interesting compound for potential applications in food preservation or clinical settings.
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Affiliation(s)
- Verena Vogel
- Institute of Medical Microbiology and Hygiene, Ulm University Medical Center, Ulm, Germany
| | - Richard Bauer
- Institute of Medical Microbiology and Hygiene, Ulm University Medical Center, Ulm, Germany
| | - Stefanie Mauerer
- Institute of Medical Microbiology and Hygiene, Ulm University Medical Center, Ulm, Germany
| | | | - Christian Haupt
- Institute of Protein Biochemistry, Ulm University, Ulm, Germany
| | - Gerd M Seibold
- Department of Biotechnology and Biomedicine, Technical University of Denmark, Kongens Lyngby, Denmark
| | - Marcus Fändrich
- Institute of Protein Biochemistry, Ulm University, Ulm, Germany
| | - Paul Walther
- Central Facility for Electron Microscopy, Ulm University, Ulm, Germany
| | - Barbara Spellerberg
- Institute of Medical Microbiology and Hygiene, Ulm University Medical Center, Ulm, Germany.
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4
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Short- and long-term effects of copper on anammox under gradually increased copper concentrations. Biodegradation 2021; 32:273-286. [PMID: 33745118 DOI: 10.1007/s10532-021-09934-1] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2020] [Accepted: 03/05/2021] [Indexed: 10/21/2022]
Abstract
This study aims to determine both short- and long-term response of enriched anammox culture to Cu. Assessment of short-term inhibition is based both on total applied Cu concentration and potential bioavailable fractions like intracellular, surface-bound, soluble and free Cu ion. The half maximal inhibitory concentration (IC50) values for total applied, soluble, intracellular and cell-associated concentrations were determined as 4.57 mg/L, 1.97 mg/L, 0.71 mg/L, 1.11 mg/L, respectively. Correlation between the surface-bound fraction of Cu and inhibition response was weak, suggesting that Cu sorbed to biomass was not directly responsible for the effects on anammox activity. There was a disparity between the results of short- and long-term experiments in terms of inhibition threshold concentration (i.e. short-term IC50 = 4.57 mg/L vs long-term IC50 = 6.74 mg/L). Candidatus Kuenenia (59.8%) and Candidatus Brocadia (40.2%) were the two main anammox genera within the initial biomass sample. One of the most interesting finding of the study is the demonstration that a complete wash-out of C. Brocadia genus at an applied Cu concentration of 6.5 mg/L. This strongly indicates that C. Brocadia were not able to tolerate high copper concentrations and all nitrogen conversion was carried out by C. Kuenenia during the Cu exposure period.
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CerR, a Single-Domain Regulatory Protein of the LuxR Family, Promotes Cerecidin Production and Immunity in Bacillus cereus. Appl Environ Microbiol 2018; 84:AEM.02245-17. [PMID: 29247062 DOI: 10.1128/aem.02245-17] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2017] [Accepted: 12/12/2017] [Indexed: 12/14/2022] Open
Abstract
Cerecidins are small lantibiotics from Bacillus cereus that were obtained using a semi-in vitro biosynthesis strategy and showed prominent antimicrobial activities against certain Gram-positive bacteria. However, the parental strain B. cereus As 1.1846 is incapable of producing cerecidins, most probably due to the transcriptional repression of the cerecidin gene cluster. Located in the cerecidin gene cluster, cerR encodes a putative response regulator protein that belongs to the LuxR family transcriptional regulators. CerR (84 amino acids) contains only a conserved DNA binding domain and lacks a conventional phosphorylation domain, which is rarely found in lantibiotic gene clusters. To investigate its function in cerecidin biosynthesis, cerR was constitutively expressed in B. cereus As 1.1846. Surprisingly, Constitutive expression of cerR enabled the production of cerecidins and enhanced self-immunity of B. cereus toward cerecidins. Reverse transcription-PCR analysis and electrophoresis mobility shift assays indicated, respectively, that the cer cluster was transcribed in two transcripts (cerAM and cerRTPFE) and that CerR regulated the cerecidin gene cluster directly by binding to the two predicted promoter regions of cerA and cerR DNase I footprinting experiments further confirmed that CerR specifically bound to the two promoter regions at a conserved inverted repeat sequence that was designated a CerR binding motif (cerR box). The present study demonstrated that CerR, as the first single-domain LuxR family transcriptional regulator, serves as a transcriptional activator in cerecidin biosynthesis and activates the cerecidin gene cluster, which was otherwise cryptic in B. cereusIMPORTANCE Lantibiotics with intriguing and prominent bioactivities are potential peptide antibiotics that could be applied in many areas, including food and pharmaceutical industries. The biosynthesis of lantibiotics is generally controlled by two-component regulatory systems consisting of histidine kinases and response regulators, while some unique and interesting regulatory systems are also revealed with the ever-increasing discovery of lantibiotic gene clusters among diverse microorganisms. Dissection of diverse lantibiotic regulation machineries would permit deep understanding of the biological functions of lantibiotics in different niches and even enable genetic activation of lantibiotic gene clusters that are otherwise cryptic. The significance of our study is to illuminate the regulatory mechanism of a special single-domain protein, CerR, in regulating cerecidin biosynthesis in Bacillus cereus, providing a possible novel approach to activate cryptic lantibiotic clusters.
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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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Repka LM, Chekan JR, Nair SK, van der Donk WA. Mechanistic Understanding of Lanthipeptide Biosynthetic Enzymes. Chem Rev 2017; 117:5457-5520. [PMID: 28135077 PMCID: PMC5408752 DOI: 10.1021/acs.chemrev.6b00591] [Citation(s) in RCA: 331] [Impact Index Per Article: 47.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Abstract
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Lanthipeptides
are ribosomally synthesized and post-translationally
modified peptides (RiPPs) that display a wide variety of biological
activities, from antimicrobial to antiallodynic. Lanthipeptides that
display antimicrobial activity are called lantibiotics. The post-translational
modification reactions of lanthipeptides include dehydration of Ser
and Thr residues to dehydroalanine and dehydrobutyrine, a transformation
that is carried out in three unique ways in different classes of lanthipeptides.
In a cyclization process, Cys residues then attack the dehydrated
residues to generate the lanthionine and methyllanthionine thioether
cross-linked amino acids from which lanthipeptides derive their name.
The resulting polycyclic peptides have constrained conformations that
confer their biological activities. After installation of the characteristic
thioether cross-links, tailoring enzymes introduce additional post-translational
modifications that are unique to each lanthipeptide and that fine-tune
their activities and/or stability. This review focuses on studies
published over the past decade that have provided much insight into
the mechanisms of the enzymes that carry out the post-translational
modifications.
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Affiliation(s)
- Lindsay M Repka
- Howard Hughes Medical Institute and Department of Chemistry, ‡Department of Biochemistry, and §Center for Biophysics and Computational Biology, University of Illinois at Urbana-Champaign , 600 South Mathews Avenue, Urbana, Illinois 61801, United States
| | - Jonathan R Chekan
- Howard Hughes Medical Institute and Department of Chemistry, ‡Department of Biochemistry, and §Center for Biophysics and Computational Biology, University of Illinois at Urbana-Champaign , 600 South Mathews Avenue, Urbana, Illinois 61801, United States
| | - Satish K Nair
- Howard Hughes Medical Institute and Department of Chemistry, ‡Department of Biochemistry, and §Center for Biophysics and Computational Biology, University of Illinois at Urbana-Champaign , 600 South Mathews Avenue, Urbana, Illinois 61801, United States
| | - Wilfred A van der Donk
- Howard Hughes Medical Institute and Department of Chemistry, ‡Department of Biochemistry, and §Center for Biophysics and Computational Biology, University of Illinois at Urbana-Champaign , 600 South Mathews Avenue, Urbana, Illinois 61801, United States
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Ge X, Teng K, Wang J, Zhao F, Wang F, Zhang J, Zhong J. Ligand determinants of nisin for its induction activity. J Dairy Sci 2016; 99:5022-5031. [PMID: 27132090 DOI: 10.3168/jds.2015-10809] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2015] [Accepted: 03/23/2016] [Indexed: 11/19/2022]
Abstract
Nisin has been widely used in the food industry as a safe and natural preservative and has the potential to be used as a biomedicine. Improving nisin production is important for its enormous applications. Nisin A is produced in Lactococcus lactis and its biosynthesis is induced through the regulation of the 2-component system NisKR. In this study, alanine-scanning mutagenesis was applied to study the key structure or AA in nisin for inducing the 2-component system NisKR to regulate downstream gene expression. Assay of β-galactosidase activity revealed that either ring A or ring B was necessary for nisin to induce lacZ reporter gene expression. A substituted first ring formed by Thr2 and Cys7 in S3A instead of ring A (formed by Ser3 and Cys7) fully retained nisin induction activity. Mutation of cationic AA and addition of cationic ions hardly affected nisin induction activity. These results demonstrated that the N-terminal ring structures in nisin were involved in activating NisKR to act as an inducing molecule, whereas the electrostatic force might not contribute to this process. In addition, 2 specific residues were revealed to have potential for improving both nisin induction and antimicrobial activity, which might be used for increasing nisin production.
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Affiliation(s)
- Xiaoxuan Ge
- State Key Laboratory of Microbial Resources, Institute of Microbiology, Chinese Academy of Sciences, Beijing 100101, People's Republic of China; University of Chinese Academy of Sciences, Beijing 100101, People's Republic of China
| | - Kunling Teng
- State Key Laboratory of Microbial Resources, Institute of Microbiology, Chinese Academy of Sciences, Beijing 100101, People's Republic of China.
| | - Jian Wang
- State Key Laboratory of Microbial Resources, Institute of Microbiology, Chinese Academy of Sciences, Beijing 100101, People's Republic of China; College of Engineering, University of Georgia, Athens 30602
| | - Fangyuan Zhao
- State Key Laboratory of Microbial Resources, Institute of Microbiology, Chinese Academy of Sciences, Beijing 100101, People's Republic of China; University of Chinese Academy of Sciences, Beijing 100101, People's Republic of China
| | - Fangfang Wang
- State Key Laboratory of Microbial Resources, Institute of Microbiology, Chinese Academy of Sciences, Beijing 100101, People's Republic of China; University of Chinese Academy of Sciences, Beijing 100101, People's Republic of China
| | - Jie Zhang
- State Key Laboratory of Microbial Resources, Institute of Microbiology, Chinese Academy of Sciences, Beijing 100101, People's Republic of China; University of Chinese Academy of Sciences, Beijing 100101, People's Republic of China
| | - Jin Zhong
- State Key Laboratory of Microbial Resources, Institute of Microbiology, Chinese Academy of Sciences, Beijing 100101, People's Republic of China.
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Bacteriocins of lactic acid bacteria: extending the family. Appl Microbiol Biotechnol 2016; 100:2939-51. [PMID: 26860942 PMCID: PMC4786598 DOI: 10.1007/s00253-016-7343-9] [Citation(s) in RCA: 410] [Impact Index Per Article: 51.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2015] [Revised: 01/18/2016] [Accepted: 01/22/2016] [Indexed: 12/24/2022]
Abstract
Lactic acid bacteria (LAB) constitute a heterogeneous group of microorganisms that produce lactic acid as the major product during the fermentation process. LAB are Gram-positive bacteria with great biotechnological potential in the food industry. They can produce bacteriocins, which are proteinaceous antimicrobial molecules with a diverse genetic origin, posttranslationally modified or not, that can help the producer organism to outcompete other bacterial species. In this review, we focus on the various types of bacteriocins that can be found in LAB and the organization and regulation of the gene clusters responsible for their production and biosynthesis, and consider the food applications of the prototype bacteriocins from LAB. Furthermore, we propose a revised classification of bacteriocins that can accommodate the increasing number of classes reported over the last years.
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Teng K, Zhang J, Zhang X, Ge X, Gao Y, Wang J, Lin Y, Zhong J. Identification of ligand specificity determinants in lantibiotic bovicin HJ50 and the receptor BovK, a multitransmembrane histidine kinase. J Biol Chem 2014; 289:9823-32. [PMID: 24526683 DOI: 10.1074/jbc.m113.513150] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Lantibiotic bovicin HJ50 is produced by Streptococcus bovis HJ50 and acts as the extracellular signal to autoregulate its own biosynthesis through BovK/R two-component system. Bovicin HJ50 shows a linear N-terminal and glubolar C-terminal structure, and the sensor histidine kinase BovK contains eight transmembrane segments lacking any extensive surface-exposed sensory domain. The signal recognition mechanism between bovicin HJ50 and BovK is still unknown. We performed saturated alanine scanning mutagenesis and other amino acid substitutions on bovicin HJ50 using a semi-in vitro biosynthesis. Results of the mutants inducing activities indicated that several charged and hydrophobic amino acids in ring B of bovicin HJ50, as well as two glycines were key residues to recognize BovK. Circular dichroism analyses indicated that both glycines contributed to bovicin HJ50 structural changes in the membrane. Biotin-labeled bovicin HJ50 could interact with the N-terminal sensor of BovK, and several charged residues and a conserved hydrophobic region in the N-terminal portion of BovK sensor domain were important for interacting with the signal bovicin HJ50. By combining the results, we suggested a mechanism of bovicin HJ50 recognizing and activating BovK mainly through electrostatic and hydrophobic interactions.
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Affiliation(s)
- Kunling Teng
- From the State Key Laboratory of Microbial Resources, Institute of Microbiology, Chinese Academy of Sciences and
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Restoration of bioactive lantibiotic suicin from a remnant lan locus of pathogenic Streptococcus suis serotype 2. Appl Environ Microbiol 2013; 80:1062-71. [PMID: 24271178 DOI: 10.1128/aem.03213-13] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Lantibiotics are ribosomally synthesized, posttranslationally modified antimicrobial peptides. Their biosynthesis genes are usually organized in gene clusters, which are mainly found in Gram-positive bacteria, including pathogenic streptococci. Three highly virulent Streptococcus suis serotype 2 strains (98HAH33, 05ZYH33, and SC84) have been shown to contain an 89K pathogenicity island. Here, on these islands, we unveiled and reannotated a putative lantibiotic locus designated sui which contains a virulence-associated two-component regulator, suiK-suiR. In silico analysis revealed that the putative lantibiotic modification gene suiM was interrupted by a 7.9-kb integron and that other biosynthesis-related genes contained various frameshift mutations. By reconstituting the intact suiM in Escherichia coli together with a semi-in vitro biosynthesis system, a putative lantibiotic named suicin was produced with bactericidal activities against a variety of Gram-positive strains, including pathogenic streptococci and vancomycin-resistant enterococci. Ring topology dissection indicated that the 34-amino-acid lantibiotic contained two methyllanthionine residues and one disulfide bridge, which render suicin in an N-terminal linear and C-terminal globular shape. To confirm the function of suiK-suiR, SuiR was overexpressed and purified. In vitro analysis showed that SuiR could specifically bind to the suiA gene promoter. Its coexpression with suiK could activate suiA gene promoter in Lactococcus lactis NZ9000. Conclusively, we obtained a novel lantibiotic suicin by restoring its production from the remnant sui locus and demonstrated that virulence-associated SuiK-SuiR regulates its production.
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12
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Barbour A, Philip K, Muniandy S. Enhanced production, purification, characterization and mechanism of action of salivaricin 9 lantibiotic produced by Streptococcus salivarius NU10. PLoS One 2013; 8:e77751. [PMID: 24147072 PMCID: PMC3797685 DOI: 10.1371/journal.pone.0077751] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2013] [Accepted: 09/06/2013] [Indexed: 01/28/2023] Open
Abstract
Background Lantibiotics are small lanthionine-containing bacteriocins produced by lactic acid bacteria. Salivaricin 9 is a newly discovered lantibiotic produced by Streptococcus salivarius. In this study we present the mechanism of action of salivaricin 9 and some of its properties. Also we developed new methods to produce and purify the lantibiotic from strain NU10. Methodology / Principal Findings Salivaricin 9 was found to be auto-regulated when an induction assay was applied and this finding was used to develop a successful salivaricin 9 production system in liquid medium. A combination of XAD-16 and cation exchange chromatography was used to purify the secondary metabolite which was shown to have a molecular weight of approximately 3000 Da by SDS-PAGE. MALDI-TOF MS analysis indicated the presence of salivaricin 9, a 2560 Da lantibiotic. Salivaricin 9 is a bactericidal molecule targeting the cytoplasmic membrane of sensitive cells. The membrane permeabilization assay showed that salivaricin 9 penetrated the cytoplasmic membrane and induced pore formation which resulted in cell death. The morphological changes of test bacterial strains incubated with salivaricin 9 were visualized using Scanning Electron Microscopy which confirmed a pore forming mechanism of inhibition. Salivaricin 9 retained biological stability when exposed to high temperature (90-100°C) and stayed bioactive at pH ranging 2 to 10. When treated with proteinase K or peptidase, salivaricin 9 lost all antimicrobial activity, while it remained active when treated with lyticase, catalase and certain detergents. Conclusion The mechanism of antimicrobial action of a newly discovered lantibiotic salivaricin 9 was elucidated in this study. Salivaricin 9 penetrated the cytoplasmic membrane of its targeted cells and induced pore formation. This project has given new insights on lantibiotic peptides produced by S. salivarius isolated from the oral cavities of Malaysian subjects.
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Affiliation(s)
- Abdelahhad Barbour
- Institute of Biological Sciences, Microbiology Division, Faculty of Science, University of Malaya, Kuala Lumpur, Malaysia
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Macedovicin, the second food-grade lantibiotic produced by Streptococcus macedonicus ACA-DC 198. Food Microbiol 2013; 33:124-30. [DOI: 10.1016/j.fm.2012.09.008] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2012] [Revised: 07/14/2012] [Accepted: 09/19/2012] [Indexed: 11/20/2022]
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