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Mayo-Pérez S, Gama-Martínez Y, Dávila S, Rivera N, Hernández-Lucas I. LysR-type transcriptional regulators: state of the art. Crit Rev Microbiol 2023:1-33. [PMID: 37635411 DOI: 10.1080/1040841x.2023.2247477] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2023] [Revised: 08/03/2023] [Accepted: 08/08/2023] [Indexed: 08/29/2023]
Abstract
The LysR-type transcriptional regulators (LTTRs) are DNA-binding proteins present in bacteria, archaea, and in algae. Knowledge about their distribution, abundance, evolution, structural organization, transcriptional regulation, fundamental roles in free life, pathogenesis, and bacteria-plant interaction has been generated. This review focuses on these aspects and provides a current picture of LTTR biology.
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Affiliation(s)
- S Mayo-Pérez
- Departamento de Microbiología Molecular, Instituto de Biotecnología, Universidad Nacional Autónoma de México, Cuernavaca, Mexico
| | - Y Gama-Martínez
- Departamento de Microbiología Molecular, Instituto de Biotecnología, Universidad Nacional Autónoma de México, Cuernavaca, Mexico
| | - S Dávila
- Centro de Investigación en Dinámica Celular, Universidad Autónoma del Estado de Morelos, Cuernavaca, Mexico
| | - N Rivera
- IPN: CICATA, Unidad Morelos del Instituto Politécnico Nacional, Atlacholoaya, Mexico
| | - I Hernández-Lucas
- Departamento de Microbiología Molecular, Instituto de Biotecnología, Universidad Nacional Autónoma de México, Cuernavaca, Mexico
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2
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Abanoz-Seçgin B, Otur Ç, Okay S, Kurt-Kızıldoğan A. The regulatory role of Fur-encoding SCLAV_3199 in iron homeostasis in Streptomyces clavuligerus. Gene 2023:147594. [PMID: 37364696 DOI: 10.1016/j.gene.2023.147594] [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: 03/14/2023] [Revised: 06/09/2023] [Accepted: 06/23/2023] [Indexed: 06/28/2023]
Abstract
Iron homeostasis is strictly regulated by complex cascades connected with secondary metabolism in bacteria. Ferric uptake regulators ('Fur's), siderophores, efflux systems, and two-component signal transduction systems are the leading players in response stimuli. However, these regulatory mechanisms remain to be elucidated in Streptomyces clavuligerus. Our study focused on unraveling a possible role of SCLAV_3199 which encodes a Fur family transcriptional regulator, particularly in iron regulation and at the global level in this species. We deleted the SCLAV_3199 gene in S. clavuligerus and compared gene expression differences with the wild-type strain based on iron availability by RNA-seq. We found a potential regulatory effect of SCLAV_3199 on many transcriptional regulators and transporters. Besides, the genes encoding iron sulfur binding proteins were overexpressed in the mutant in the presence of iron. Notably, catechol (SCLAV_5397), and hydroxamate-type (SCLAV_1952, SCLAV_4680) siderophore-related genes were upregulated in the mutant strain in iron scarcity. Concomitantly, S. clavuligerus Δ3199 produced 1.65 and 1.9 times more catechol and hydroxamate-type siderophores, respectively, than that of the wild type strain under iron depletion. Iron containing chemically defined medium did not favor antibiotic production in S. clavuligerus Δ3199 while fermentation in starch-asparagine medium led to improved cephamycin C (2.23-fold) and clavulanic acid (2.56-fold) production in the mutant compared to the control. However, better tunicamycin yield (2.64-fold) was obtained in trypticase soy broth-grown cultures of S. clavuligerus Δ3199. Our findings demonstrate that the SCLAV_3199 gene plays a significant role in regulating both iron homeostasis and secondary metabolite biosynthesis in S. clavuligerus.
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Affiliation(s)
- Büşra Abanoz-Seçgin
- Department of Agricultural Biotechnology, Ondokuz Mayıs University, Samsun 55139, Türkiye
| | - Çiğdem Otur
- Department of Agricultural Biotechnology, Ondokuz Mayıs University, Samsun 55139, Türkiye
| | - Sezer Okay
- Department of Vaccine Technology, Vaccine Institute, Hacettepe University, Ankara, 06230, Türkiye
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An integrative-omics analysis of an industrial clavulanic acid-overproducing Streptomyces clavuligerus. Appl Microbiol Biotechnol 2022; 106:6139-6156. [PMID: 35945361 DOI: 10.1007/s00253-022-12098-4] [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: 03/06/2022] [Revised: 07/21/2022] [Accepted: 07/23/2022] [Indexed: 11/02/2022]
Abstract
Clavulanic acid (CA) is a clinically important secondary metabolite used to treat infectious diseases. We aimed to decipher complex regulatory mechanisms acting in CA biosynthesis by analyzing transcriptome- and proteome-wide alterations in an industrial CA overproducer Streptomyces clavuligerus strain, namely DEPA and its wild-type counterpart NRRL3585. A total of 924 differentially expressed genes (DEGs) and 271 differentially produced proteins (DPPs) were obtained by RNA-seq and nanoLC-MS/MS analyses, respectively. In particular, CA biosynthetic genes, namely, car (cad), cas2, oat2, pah, bls, ceas2, orf12, and claR, a cluster situated regulatory (CSR) gene, were significantly upregulated as shown by RNA-seq. Enzymes of clavam biosynthesis were downregulated considerably in the DEPA strain, while the genes involved in the arginine biosynthesis, one of the precursors of CA pathway, were overexpressed. However, the biosynthesis of the other CA precursor, glyceraldehyde-3-phosphate (G3P), was not affected. CA overproduction in the DEPA strain was correlated with BldD, BldG, BldM, and BldN (AdsA) overrepresentation. In addition, TetR, WhiB, and Xre family transcriptional regulators were shown to be significantly overrepresented. Several uncharacterized/unknown proteins differentially expressed in the DEPA strain await further studies for functional characterization. Correlation analysis indicated an acceptable degree of consistency between the transcriptome and proteome data. The study represents the first integrative-omics analysis in a CA overproducer S. clavuligerus strain, providing insights into the critical control points and potential rational engineering targets for a purposeful increase of CA yields in strain improvement. KEY POINTS: ∙ Transcriptome and proteome-wide alterations in industrial CA overproducer strain DEPA ∙ An acceptable degree of consistency between the transcriptome and proteome data ∙ New targets to be exploited for rational engineering.
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Abstract
The Streptomyces clavuligerus genome consists in a linear chromosome of about 6.7 Mb and four plasmids (pSCL1 to pSCL4), the latter one of 1.8 Mb. Deletion of pSCL4, results in viable mutants with high instability in the chromosome arms, which may lead to chromosome circularisation. Transcriptomic and proteomic studies comparing different mutants with the wild-type strain improved our knowledge on the biosynthesis and regulation of clavulanic acid, cephamycin C and holomycin. Additional knowledge has been obtained on the SARP-type CcaR activator and the network of connections with other regulators (Brp, AreB, AdpA, BldG, RelA) controlling ccaR expression. The transcriptional pattern of the cephamycin and clavulanic acid clusters is supported by the binding of CcaR to different promoters and confirmed that ClaR is a CcaR-dependent activator that controls the late steps of clavulanic biosynthesis. Metabolomic studies allowed the detection of new metabolites produced by S. clavuligerus such as naringenin, desferroxamines, several N-acyl tunicamycins, the terpenes carveol and cuminyl alcohol or bafilomycin J. Heterologous expression of S. clavuligerus terpene synthases resulted in the formation of no less than 15 different terpenes, although none of them was detected in S. clavuligerus culture broth. In summary, application of the Omic tools results in a better understanding of the molecular biology of S. clavuligerus, that allows the use of this strain as an industrial actinobacterial platform and helps to improve CA production.
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Affiliation(s)
- Paloma Liras
- Microbiology Section. Department of Molecular Biology University of León, León 24071. Spain
| | - Juan F Martín
- Microbiology Section. Department of Molecular Biology University of León, León 24071. Spain
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Planckaert S, Deflandre B, de Vries AM, Ameye M, Martins JC, Audenaert K, Rigali S, Devreese B. Identification of Novel Rotihibin Analogues in Streptomyces scabies, Including Discovery of Its Biosynthetic Gene Cluster. Microbiol Spectr 2021; 9:e0057121. [PMID: 34346752 PMCID: PMC8552735 DOI: 10.1128/spectrum.00571-21] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2021] [Accepted: 06/29/2021] [Indexed: 02/01/2023] Open
Abstract
Streptomyces scabies is a phytopathogen associated with common scab disease. This is mainly attributed to its ability to produce the phytotoxin thaxtomin A, the biosynthesis of which is triggered by cellobiose. During a survey of other metabolites released in the presence of cellobiose, we discovered additional compounds in the thaxtomin-containing extract from Streptomyces scabies. Structural analysis by mass spectrometry (MS) and nuclear magnetic resonance (NMR) revealed that these compounds are amino acid sequence variants of the TOR (target of rapamycin) kinase (TORK) pathway-inhibitory lipopeptide rotihibin A, and the main compounds were named rotihibins C and D. In contrast to thaxtomin, the production of rotihibins C and D was also elicited in the presence of glucose, indicating different regulation of their biosynthesis. Through a combination of shotgun and targeted proteomics, the putative rotihibin biosynthetic gene cluster rth was identified in the publicly available genome of S. scabies 87-22. This cluster spans 33 kbp and encodes 2 different nonribosomal peptide synthetases (NRPSs) and 12 additional enzymes. Homologous rth biosynthetic gene clusters were found in other publicly available and complete actinomycete genomes. Rotihibins C and D display herbicidal activity against Lemna minor and Arabidopsis thaliana at low concentrations, shown by monitoring the effects on growth and the maximal photochemistry efficiency of photosystem II. IMPORTANCE Rotihibins A and B are plant growth inhibitors acting on the TORK pathway. We report the isolation and characterization of new sequence analogues of rotihibin from Streptomyces scabies, a major cause of common scab in potato and other tuber and root vegetables. By combining proteomics data with genomic analysis, we found a cryptic biosynthetic gene cluster coding for enzyme machinery capable of rotihibin production. This work may lead to the biotechnological production of variants of this lipopeptide to investigate the exact mechanism by which it can target the plant TORK pathway in Arabidopsis thaliana. In addition, bioinformatics revealed the existence of other variants in plant-associated Streptomyces strains, both pathogenic and nonpathogenic species, raising new questions about the actual function of this lipopeptide. The discovery of a module in the nonribosomal peptide synthetase (NRPS) that incorporates the unusual citrulline residue may improve the prediction of peptides encoded by cryptic NRPS gene clusters.
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Affiliation(s)
- Sören Planckaert
- Laboratory for Microbiology, Department of Biochemistry and Microbiology, Ghent University, Ghent, Belgium
| | - Benoit Deflandre
- InBioS-Centre for Protein Engineering, Institut de Chimie B6a, University of Liège, Liège, Belgium
| | | | - Maarten Ameye
- Laboratory of Applied Mycology and Phenomics, Department of Plants and Crops, Ghent University, Ghent, Belgium
| | - José C. Martins
- NMR and Structure Analysis Group, Ghent University, Ghent, Belgium
| | - Kris Audenaert
- Laboratory of Applied Mycology and Phenomics, Department of Plants and Crops, Ghent University, Ghent, Belgium
| | - Sébastien Rigali
- InBioS-Centre for Protein Engineering, Institut de Chimie B6a, University of Liège, Liège, Belgium
| | - Bart Devreese
- Laboratory for Microbiology, Department of Biochemistry and Microbiology, Ghent University, Ghent, Belgium
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López-Agudelo VA, Gómez-Ríos D, Ramirez-Malule H. Clavulanic Acid Production by Streptomyces clavuligerus: Insights from Systems Biology, Strain Engineering, and Downstream Processing. Antibiotics (Basel) 2021; 10:84. [PMID: 33477401 PMCID: PMC7830376 DOI: 10.3390/antibiotics10010084] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2020] [Revised: 01/11/2021] [Accepted: 01/12/2021] [Indexed: 12/16/2022] Open
Abstract
Clavulanic acid (CA) is an irreversible β-lactamase enzyme inhibitor with a weak antibacterial activity produced by Streptomyces clavuligerus (S. clavuligerus). CA is typically co-formulated with broad-spectrum β‑lactam antibiotics such as amoxicillin, conferring them high potential to treat diseases caused by bacteria that possess β‑lactam resistance. The clinical importance of CA and the complexity of the production process motivate improvements from an interdisciplinary standpoint by integrating metabolic engineering strategies and knowledge on metabolic and regulatory events through systems biology and multi-omics approaches. In the large-scale bioprocessing, optimization of culture conditions, bioreactor design, agitation regime, as well as advances in CA separation and purification are required to improve the cost structure associated to CA production. This review presents the recent insights in CA production by S. clavuligerus, emphasizing on systems biology approaches, strain engineering, and downstream processing.
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Affiliation(s)
| | - David Gómez-Ríos
- Grupo de Investigación en Simulación, Diseño, Control y Optimización de Procesos (SIDCOP), Departamento de Ingeniería Química, Universidad de Antioquia UdeA, Calle 70 No. 52-21, Medellín 050010, Colombia;
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Baş L, Otur Ç, Kurt-Kızıldoğan A. Enhanced Tunicamycin Biosynthesis in BldG Overexpressed Streptomyces clavuligerus. APPL BIOCHEM MICRO+ 2020. [DOI: 10.1134/s000368382004002x] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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Abstract
Natural products produced by Streptomyces species underpin many industrially and medically important compounds. However, the majority of the ∼30 biosynthetic pathways harbored by an average species are not expressed in the laboratory. This unrevealed biochemical diversity is believed to comprise an untapped resource for natural product drug discovery. Major roadblocks preventing the exploitation of unexpressed biosynthetic pathways are a lack of insight into their regulation and limited technology for activating their expression. Our findings reveal that the abundance of σAntA, which is the cluster-situated regulator of antimycin biosynthesis, is controlled by the ClpXP protease. These data link proteolysis to the regulation of natural product biosynthesis for the first time to our knowledge, and we anticipate that this will emerge as a major strategy by which actinobacteria regulate production of their natural products. Further study of this process will advance understanding of how expression of secondary metabolism is controlled and will aid pursuit of activating unexpressed biosynthetic pathways. The survival of any microbe relies on its ability to respond to environmental change. Use of extracytoplasmic function (ECF) RNA polymerase sigma (σ) factors is a major strategy enabling dynamic responses to extracellular signals. Streptomyces species harbor a large number of ECF σ factors, nearly all of which are uncharacterized, but those that have been characterized generally regulate genes required for morphological differentiation and/or response to environmental stress, except for σAntA, which regulates starter-unit biosynthesis in the production of antimycin, an anticancer compound. Unlike a canonical ECF σ factor, whose activity is regulated by a cognate anti-σ factor, σAntA is an orphan, raising intriguing questions about how its activity may be controlled. Here, we reconstituted in vitro ClpXP proteolysis of σAntA but not of a variant lacking a C-terminal di-alanine motif. Furthermore, we show that the abundance of σAntAin vivo was enhanced by removal of the ClpXP recognition sequence and that levels of the protein rose when cellular ClpXP protease activity was abolished. These data establish direct proteolysis as an alternative and, thus far, unique control strategy for an ECF RNA polymerase σ factor and expands the paradigmatic understanding of microbial signal transduction regulation. IMPORTANCE Natural products produced by Streptomyces species underpin many industrially and medically important compounds. However, the majority of the ∼30 biosynthetic pathways harbored by an average species are not expressed in the laboratory. This unrevealed biochemical diversity is believed to comprise an untapped resource for natural product drug discovery. Major roadblocks preventing the exploitation of unexpressed biosynthetic pathways are a lack of insight into their regulation and limited technology for activating their expression. Our findings reveal that the abundance of σAntA, which is the cluster-situated regulator of antimycin biosynthesis, is controlled by the ClpXP protease. These data link proteolysis to the regulation of natural product biosynthesis for the first time to our knowledge, and we anticipate that this will emerge as a major strategy by which actinobacteria regulate production of their natural products. Further study of this process will advance understanding of how expression of secondary metabolism is controlled and will aid pursuit of activating unexpressed biosynthetic pathways.
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Homologous expression of lysA encoding diaminopimelic acid (DAP) decarboxylase reveals increased antibiotic production in Streptomyces clavuligerus. Braz J Microbiol 2019; 51:547-556. [PMID: 31833007 DOI: 10.1007/s42770-019-00202-2] [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: 08/16/2019] [Accepted: 11/27/2019] [Indexed: 10/25/2022] Open
Abstract
lysA gene encoding meso-diaminopimelic acid (DAP) decarboxylase enzyme that catalyzes L-lysine biosynthesis in the aspartate pathway in Streptomyces clavuligerus was overexpressed, and its effects on cephamycin C (CephC), clavulanic acid (CA), and tunicamycin productions were investigated. Multicopy expression of lysA gene under the control of glpF promoter (glpFp) in S. clavuligerus pCOlysA led to higher expression levels ranging from 2- to 6-fold increase at both lysA gene and CephC biosynthetic gene cluster at T36 and T48 of TSBG fermentation. These results accorded well with CephC production. Thus, 1.86- and 3.14-fold higher volumetric as well as 1.26- and 1.71-fold increased specific CephC yields were recorded in S. clavuligerus pCOlysA in comparison with the wild-type and its control strain, respectively, at 48th h. Increasing the expression of lysA provided 4.3 times more tunicamycin yields in the recombinant strain. These findings suggested that lysA overexpression in S. clavuligerus made the strain more productive for CephC and tunicamycin. The results also supported the presence of complex interactions among antibiotic biosynthesis pathways in S. clavuligerus.
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A Single Biosynthetic Gene Cluster Is Responsible for the Production of Bagremycin Antibiotics and Ferroverdin Iron Chelators. mBio 2019; 10:mBio.01230-19. [PMID: 31409675 PMCID: PMC6692506 DOI: 10.1128/mbio.01230-19] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Access to whole-genome sequences has exposed the general incidence of the so-called cryptic biosynthetic gene clusters (BGCs), thereby renewing their interest for natural product discovery. As a consequence, genome mining is the often first approach implemented to assess the potential of a microorganism for producing novel bioactive metabolites. By revealing a new level of complexity of natural product biosynthesis, we further illustrate the difficulty of estimation of the panel of molecules associated with a BGC based on genomic information alone. Indeed, we found that the same gene cluster is responsible for the production of compounds which differ in terms of structure and bioactivity. The production of these different compounds responds to different environmental triggers, which suggests that multiplication of culture conditions is essential for revealing the entire panel of molecules made by a single BGC. Biosynthetic gene clusters (BGCs) are organized groups of genes involved in the production of specialized metabolites. Typically, one BGC is responsible for the production of one or several similar compounds with bioactivities that usually only vary in terms of strength and/or specificity. Here we show that the previously described ferroverdins and bagremycins, which are families of metabolites with different bioactivities, are produced from the same BGC, whereby the fate of the biosynthetic pathway depends on iron availability. Under conditions of iron depletion, the monomeric bagremycins are formed, representing amino-aromatic antibiotics resulting from the condensation of 3-amino-4-hydroxybenzoic acid with p-vinylphenol. Conversely, when iron is abundantly available, the biosynthetic pathway additionally produces a molecule based on p-vinylphenyl-3-nitroso-4-hydroxybenzoate, which complexes iron to form the trimeric ferroverdins that have anticholesterol activity. Thus, our work shows a unique exception to the concept that BGCs should only produce a single family of molecules with one type of bioactivity and that in fact different bioactive molecules may be produced depending on the environmental conditions.
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Comparative Transcriptome Analysis of Streptomyces Clavuligerus in Response to Favorable and Restrictive Nutritional Conditions. Antibiotics (Basel) 2019; 8:antibiotics8030096. [PMID: 31330947 PMCID: PMC6784218 DOI: 10.3390/antibiotics8030096] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2019] [Revised: 07/05/2019] [Accepted: 07/09/2019] [Indexed: 12/17/2022] Open
Abstract
Background: Clavulanic acid (CA), a β-lactamase inhibitor, is industrially produced by the fermentation of Streptomyces clavuligerus. The efficiency of CA production is associated with media composition, culture conditions and physiological and genetic strain characteristics. However, the molecular pathways that govern CA regulation in S. clavuligerus remain unknown. Methods and Results: Here we used RNA-seq to perform a comparative transcriptome analysis of S. clavuligerus ATCC 27064 wild-type strain grown in both a favorable soybean-based medium and in limited media conditions to further contribute to the understanding of S. clavuligerus metabolism and its regulation. A total of 350 genes were found to be differentially expressed between conditions; 245 genes were up-regulated in favorable conditions compared to unfavorable. Conclusion: The up-regulated expression of many regulatory and biosynthetic CA genes was positively associated with the favorable complex media condition along with pleiotropic regulators, including proteases and some genes whose biological function have not been previously reported. Knowledge from differences between transcriptomes from complex/defined media represents an advance in the understanding of regulatory paths involved in S. clavuligerus’ metabolic response, enabling the rational design of future experiments.
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Fu J, Qin R, Zong G, Liu C, Kang N, Zhong C, Cao G. The CagRS Two-Component System Regulates Clavulanic Acid Metabolism via Multiple Pathways in Streptomyces clavuligerus F613-1. Front Microbiol 2019; 10:244. [PMID: 30837970 PMCID: PMC6382702 DOI: 10.3389/fmicb.2019.00244] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2018] [Accepted: 01/29/2019] [Indexed: 11/21/2022] Open
Abstract
Streptomyces clavuligerus F613-1 produces a clinically important β-lactamase inhibitor, clavulanic acid (CA). Although the biosynthesis pathway of CA has essentially been elucidated, the global regulatory mechanisms of CA biosynthesis remain unclear. The paired genes cagS and cagR, which are annotated, respectively, as orf22 and orf23 in S. clavuligerus ATCC 27064, encode a bacterial two-component regulatory system (TCS) and were found next to the CA biosynthetic gene cluster of S. clavuligerus F613-1. To further elucidate the regulatory mechanism of CA biosynthesis, the CagRS TCS was deleted from S. clavuligerus F613-1. Deletion of cagRS resulted in decreased production of CA, but the strain phenotype was not otherwise affected. Both transcriptome and ChIP-seq data revealed that, in addition to CA biosynthesis, the CagRS TCS mainly regulates genes involved in primary metabolism, such as glyceraldehyde 3-phosphate (G3P) metabolism and arginine biosynthesis. Notably, both G3P and arginine are precursors of CA. Electrophoretic mobility shift assays demonstrated that the response regulator CagR could bind to the intergenic regions of argG, argC, oat1, oat2, ceaS1, and claR in vitro, suggesting that CagR can directly regulate genes involved in arginine and CA biosynthesis. This study indicated that CagRS is a pleiotropic regulator that can directly affect the biosynthesis of CA and indirectly affect CA production by regulating the metabolism of arginine and G3P. Our findings provide new insights into the regulation of CA biosynthetic pathways and provide an innovative approach for future metabolic engineering efforts for CA production in S. clavuligerus.
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Affiliation(s)
- Jiafang Fu
- Shandong Medicinal Biotechnology Center, Shandong Academy of Medical Sciences, Jinan, China
| | - Ronghuo Qin
- Shandong Medicinal Biotechnology Center, Shandong Academy of Medical Sciences, Jinan, China
| | - Gongli Zong
- Shandong Medicinal Biotechnology Center, Shandong Academy of Medical Sciences, Jinan, China
| | - Cheng Liu
- School of Municipal and Environmental Engineering, Shandong Jianzhu University, Jinan, China
| | - Ni Kang
- Shandong Medicinal Biotechnology Center, Shandong Academy of Medical Sciences, Jinan, China
| | - Chuanqing Zhong
- School of Municipal and Environmental Engineering, Shandong Jianzhu University, Jinan, China
| | - Guangxiang Cao
- Shandong Medicinal Biotechnology Center, Shandong Academy of Medical Sciences, Jinan, China
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Nepal KK, Wang G. Streptomycetes: Surrogate hosts for the genetic manipulation of biosynthetic gene clusters and production of natural products. Biotechnol Adv 2019; 37:1-20. [PMID: 30312648 PMCID: PMC6343487 DOI: 10.1016/j.biotechadv.2018.10.003] [Citation(s) in RCA: 46] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2018] [Revised: 09/04/2018] [Accepted: 10/05/2018] [Indexed: 12/23/2022]
Abstract
Due to the worldwide prevalence of multidrug-resistant pathogens and high incidence of diseases such as cancer, there is an urgent need for the discovery and development of new drugs. Nearly half of the FDA-approved drugs are derived from natural products that are produced by living organisms, mainly bacteria, fungi, and plants. Commercial development is often limited by the low yield of the desired compounds expressed by the native producers. In addition, recent advances in whole genome sequencing and bioinformatics have revealed an abundance of cryptic biosynthetic gene clusters within microbial genomes. Genetic manipulation of clusters in the native host is commonly used to awaken poorly expressed or silent gene clusters, however, the lack of feasible genetic manipulation systems in many strains often hinders our ability to engineer the native producers. The transfer of gene clusters into heterologous hosts for expression of partial or entire biosynthetic pathways is an approach that can be used to overcome this limitation. Heterologous expression also facilitates the chimeric fusion of different biosynthetic pathways, leading to the generation of "unnatural" natural products. The genus Streptomyces is especially known to be a prolific source of drugs/antibiotics, its members are often used as heterologous expression hosts. In this review, we summarize recent applications of Streptomyces species, S. coelicolor, S. lividans, S. albus, S. venezuelae and S. avermitilis, as heterologous expression systems.
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Affiliation(s)
- Keshav K Nepal
- Harbor Branch Oceanographic Institute, Florida Atlantic University, 5600 U.S. 1 North, Fort Pierce, FL 34946, USA
| | - Guojun Wang
- Harbor Branch Oceanographic Institute, Florida Atlantic University, 5600 U.S. 1 North, Fort Pierce, FL 34946, USA.
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Jourdan S, Francis IM, Deflandre B, Tenconi E, Riley J, Planckaert S, Tocquin P, Martinet L, Devreese B, Loria R, Rigali S. Contribution of the β-glucosidase BglC to the onset of the pathogenic lifestyle of Streptomyces scabies. MOLECULAR PLANT PATHOLOGY 2018; 19:1480-1490. [PMID: 29077242 PMCID: PMC6638027 DOI: 10.1111/mpp.12631] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/22/2017] [Revised: 10/21/2017] [Accepted: 10/22/2017] [Indexed: 05/23/2023]
Abstract
Common scab disease on root and tuber plants is caused by Streptomyces scabies and related species which use the cellulose synthase inhibitor thaxtomin A as the main phytotoxin. Thaxtomin production is primarily triggered by the import of cello-oligosaccharides. Once inside the cell, the fate of the cello-oligosaccharides is dichotomized: (i) the fuelling of glycolysis with glucose for the saprophytic lifestyle through the action of β-glucosidase(s) (BGs); and (ii) elicitation of the pathogenic lifestyle by the inhibition of CebR-mediated transcriptional repression of thaxtomin biosynthetic genes. Here, we investigated the role of scab57721, encoding a putative BG (BglC), in the onset of the pathogenicity of S. scabies. Enzymatic assays showed that BglC was able to release glucose from cellobiose, cellotriose and all other cello-oligosaccharides tested. Its inactivation resulted in a phenotype opposite to that expected, as reduced production of thaxtomin was monitored when the mutant was cultivated on medium containing cello-oligosaccharides as unique carbon source. This unexpected phenotype could be attributed to the highly increased activity of alternative intracellular BGs, probably as a compensation for bglC inactivation, which then prevented cellobiose and cellotriose accumulation to reduce the activity of CebR. In contrast, when the bglC null mutant was cultivated on medium devoid of cello-oligosaccharides, it instead constitutively produced thaxtomin. This observed hypervirulent phenotype does not fit with the proposed model of the cello-oligosaccharide-mediated induction of thaxtomin production, and suggests that the role of BglC in the route to the pathogenic lifestyle of S. scabies is more complex than currently presented.
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Affiliation(s)
- Samuel Jourdan
- InBioS – Center for Protein EngineeringUniversity of Liège, Institut de ChimieLiège B‐4000Belgium
| | - Isolde M. Francis
- Department of Plant PathologyUniversity of FloridaGainesville 32611FLUSA
- Department of BiologyCalifornia State UniversityBakersfield 93311CAUSA
| | - Benoit Deflandre
- InBioS – Center for Protein EngineeringUniversity of Liège, Institut de ChimieLiège B‐4000Belgium
| | - Elodie Tenconi
- InBioS – Center for Protein EngineeringUniversity of Liège, Institut de ChimieLiège B‐4000Belgium
| | - Jennifer Riley
- Department of BiologyCalifornia State UniversityBakersfield 93311CAUSA
| | - Sören Planckaert
- Laboratory for Protein Biochemistry and Biomolecular Engineering, Department of Biochemistry and MicrobiologyGhent UniversityGhent B‐9000Belgium
| | - Pierre Tocquin
- InBioS – CARE PhytoSYSTEMS, University of Liège, Institut de BotaniqueLiège B‐4000Belgium
| | - Loïc Martinet
- InBioS – Center for Protein EngineeringUniversity of Liège, Institut de ChimieLiège B‐4000Belgium
| | - Bart Devreese
- Laboratory for Protein Biochemistry and Biomolecular Engineering, Department of Biochemistry and MicrobiologyGhent UniversityGhent B‐9000Belgium
| | - Rosemary Loria
- Department of Plant PathologyUniversity of FloridaGainesville 32611FLUSA
| | - Sébastien Rigali
- InBioS – Center for Protein EngineeringUniversity of Liège, Institut de ChimieLiège B‐4000Belgium
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15
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Global regulator BldA regulates morphological differentiation and lincomycin production in Streptomyces lincolnensis. Appl Microbiol Biotechnol 2018; 102:4101-4115. [PMID: 29549449 DOI: 10.1007/s00253-018-8900-1] [Citation(s) in RCA: 30] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2017] [Revised: 02/25/2018] [Accepted: 02/28/2018] [Indexed: 10/17/2022]
Abstract
Global regulator BldA, the only tRNA for a rare leucine codon UUA, is best known for its ability to affect morphological differentiation and secondary metabolism in the genus Streptomyces. In this study, we confirmed the regulatory function of the bldA gene (Genbank accession no. EU124663.1) in Streptomyces lincolnensis. Disruption of bldA hinders the sporulation and lincomycin production, that can recur when complemented with a functional bldA gene. Western blotting assays demonstrate that translation of the lmbB2 gene which encodes a L-tyrosine hydroxylase is absolutely dependent on BldA; however, mistranslation of the lmbU gene which encodes a cluster-situated regulator (CSR) is observed in a bldA mutant. Intriguingly, when the preferential cognate codon CTG was used, the expression level of LmbU was not the highest compared to the usage of rare codon TTA or CTA, indicating the rare codon in this position is significant for the regulation of lmbU expression. Moreover, replacement of TTA codons in both genes with another leucin codon in the bldA mutant did not restore lincomycin production. Thus, we believe that the bldA gene regulates lincomycin production via controlling the translation of not only lmbB2 and lmbU, but also the other TTA-containing genes. In conclusion, the present study demonstrated the importance of the bldA gene in morphological differentiation and lincomycin production in S. lincolnensis.
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16
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Abstract
One of the greatest sources of metabolic and enzymatic diversity are microorganisms. In recent years, emerging recombinant DNA and genomic techniques have facilitated the development of new efficient expression systems, modification of biosynthetic pathways leading to new metabolites by metabolic engineering, and enhancement of catalytic properties of enzymes by directed evolution. Complete sequencing of industrially important microbial genomes is taking place very rapidly, and there are already hundreds of genomes sequenced. Functional genomics and proteomics are major tools used in the search for new molecules and development of higher-producing strains.
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Affiliation(s)
| | - Sergio Sánchez
- Instituto de Investigaciones Biomédicas, Universidad Nacional Autónoma de México, Ciudad de México, CDMX, México
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17
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Ferguson NL, Peña-Castillo L, Moore MA, Bignell DRD, Tahlan K. Proteomics analysis of global regulatory cascades involved in clavulanic acid production and morphological development in Streptomyces clavuligerus. ACTA ACUST UNITED AC 2016; 43:537-55. [DOI: 10.1007/s10295-016-1733-y] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2015] [Accepted: 01/02/2016] [Indexed: 12/11/2022]
Abstract
Abstract
The genus Streptomyces comprises bacteria that undergo a complex developmental life cycle and produce many metabolites of importance to industry and medicine. Streptomyces clavuligerus produces the β-lactamase inhibitor clavulanic acid, which is used in combination with β-lactam antibiotics to treat certain β-lactam resistant bacterial infections. Many aspects of how clavulanic acid production is globally regulated in S. clavuligerus still remains unknown. We conducted comparative proteomics analysis using the wild type strain of S. clavuligerus and two mutants (ΔbldA and ΔbldG), which are defective in global regulators and vary in their ability to produce clavulanic acid. Approximately 33.5 % of the predicted S. clavuligerus proteome was detected and 192 known or putative regulatory proteins showed statistically differential expression levels in pairwise comparisons. Interestingly, the expression of many proteins whose corresponding genes contain TTA codons (predicted to require the bldA tRNA for translation) was unaffected in the bldA mutant.
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Affiliation(s)
- Nicole L Ferguson
- grid.25055.37 0000000091306822 Department of Biology Memorial University of Newfoundland A1B 3X9 St. John’s NL Canada
| | - Lourdes Peña-Castillo
- grid.25055.37 0000000091306822 Department of Biology Memorial University of Newfoundland A1B 3X9 St. John’s NL Canada
- grid.25055.37 0000000091306822 Department of Computer Science Memorial University of Newfoundland A1B 3X5 St. John’s NL Canada
| | - Marcus A Moore
- grid.25055.37 0000000091306822 Department of Biology Memorial University of Newfoundland A1B 3X9 St. John’s NL Canada
| | - Dawn R D Bignell
- grid.25055.37 0000000091306822 Department of Biology Memorial University of Newfoundland A1B 3X9 St. John’s NL Canada
| | - Kapil Tahlan
- grid.25055.37 0000000091306822 Department of Biology Memorial University of Newfoundland A1B 3X9 St. John’s NL Canada
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18
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Bignell DRD, Francis IM, Fyans JK, Loria R. Thaxtomin A production and virulence are controlled by several bld gene global regulators in Streptomyces scabies. MOLECULAR PLANT-MICROBE INTERACTIONS : MPMI 2014; 27:875-85. [PMID: 24678834 DOI: 10.1094/mpmi-02-14-0037-r] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
Streptomyces scabies is the main causative agent of common scab disease, which leads to significant annual losses to potato growers worldwide. The main virulence factor produced by S. scabies is a phytotoxic secondary metabolite called thaxtomin A, which functions as a cellulose synthesis inhibitor. Thaxtomin A production is controlled by the cluster-situated regulator TxtR, which activates expression of the thaxtomin biosynthetic genes in response to cello-oligosaccharides. Here, we demonstrate that at least five additional regulatory genes are required for wild-type levels of thaxtomin A production and plant pathogenicity in S. scabies. These regulatory genes belong to the bld gene family of global regulators that control secondary metabolism or morphological differentiation in Streptomyces spp. Quantitative reverse-transcriptase polymerase chain reaction showed that expression of the thaxtomin biosynthetic genes was significantly downregulated in all five bld mutants and, in four of these mutants, this downregulation was attributed to the reduction in expression of txtR. Furthermore, all of the mutants displayed reduced expression of other known or predicted virulence genes, suggesting that the bld genes may function as global regulators of virulence gene expression in S. scabies.
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19
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Seipke RF, Patrick E, Hutchings MI. Regulation of antimycin biosynthesis by the orphan ECF RNA polymerase sigma factor σ (AntA.). PeerJ 2014; 2:e253. [PMID: 24688837 PMCID: PMC3933326 DOI: 10.7717/peerj.253] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2013] [Accepted: 01/07/2014] [Indexed: 12/03/2022] Open
Abstract
Antimycins are an extended family of depsipeptides that are made by filamentous actinomycete bacteria and were first isolated more than 60 years ago. Recently, antimycins have attracted renewed interest because of their activities against the anti-apoptotic machineries inside human cells which could make them promising anti-cancer compounds. The biosynthetic pathway for antimycins was recently characterised but very little is known about the organisation and regulation of the antimycin (ant) gene cluster. Here we report that the ant gene cluster in Streptomyces albus is organized into four transcriptional units; the antBA, antCDE, antGF and antHIJKLMNO operons. Unusually for secondary metabolite clusters, the antG and antH promoters are regulated by an extracytoplasmic function (ECF) RNA polymerase sigma factor named σAntA which represents a new sub-family of ECF σ factors that is only found in antimycin producing strains. We show that σAntA controls production of the unusual precursor 3-aminosalicylate which is absolutely required for the production of antimycins. σAntA is highly conserved in antimycin producing strains and the −10 and −35 elements at the σAntA regulated antG and antH promoters are also highly conserved suggesting a common mechanism of regulation. We also demonstrate that altering the C-terminal Ala-Ala residues found in all σAntA proteins to Asp-Asp increases expression of the antFG and antGHIJKLMNO operons and we speculate that this Ala-Ala motif may be a signal for the protease ClpXP.
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Affiliation(s)
- Ryan F Seipke
- School of Biological Sciences, University of East Anglia , Norwich Research Park , Norwich , United Kingdom
| | - Elaine Patrick
- School of Biological Sciences, University of East Anglia , Norwich Research Park , Norwich , United Kingdom
| | - Matthew I Hutchings
- School of Biological Sciences, University of East Anglia , Norwich Research Park , Norwich , United Kingdom
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20
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Alvarez-Álvarez R, Martínez-Burgo Y, Pérez-Redondo R, Braña AF, Martín JF, Liras P. Expression of the endogenous and heterologous clavulanic acid cluster in Streptomyces flavogriseus: why a silent cluster is sleeping. Appl Microbiol Biotechnol 2013; 97:9451-63. [PMID: 23974366 DOI: 10.1007/s00253-013-5148-7] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2013] [Revised: 07/22/2013] [Accepted: 07/24/2013] [Indexed: 10/26/2022]
Abstract
Clusters for clavulanic acid (CA) biosynthesis are present in the actinomycetes Streptomyces flavogriseus ATCC 33331 and Saccharomonospora viridis DSM 43017. These clusters, which are silent, contain blocks of conserved genes in the same order as those of the Streptomyces clavuligerus CA cluster but assembled in a different organization. S. flavogriseus was grown in nine different media, but clavulanic acid production was undetectable using bioassays or by high-performance liquid chromatography analyses. Reverse-transcriptase polymerase chain reaction (RT-PCR) of S. flavogriseus CA biosynthesis genes showed that the regulatory genes ccaR and claR and some biosynthetic genes were expressed whereas expression of cyp, orf12, orf13, and oppA2 was undetectable. The ccaR gene of S. clavuligerus was unable to switch on CA production in S. flavogriseus::[Pfur-ccaR C], but insertion of a cosmid carrying the S. clavuligerus CA cluster (not including the ccaR gene) conferred clavulanic acid production on S. flavogriseus::[SCos-CA] particularly in TBO and YEME media; these results suggests that some of the S. flavogriseus CA genes are inactive. The known heptameric sequences recognized by CcaR in S. clavuligerus are poorly or not conserved in S. flavogriseus. Quantitative RT-PCR analysis of the CA gene clusters of S. clavuligerus and S. flavogriseus showed that the average expression value of the expressed genes in the former strain was in the order of 1.68-fold higher than in the later. The absence of CA production by S. flavogriseus can be traced to the lack of expression of the essential genes cyp, orf12, orf13, orf14, and oppA2. Heterologous expression of S. clavuligerus CA gene cluster in S. flavogriseus::[SCos-CA] was 11- to 14-fold lower than in the parental strain, suggesting that the genetic background of the host strain is important for optimal production of CA in Streptomyces.
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Affiliation(s)
- R Alvarez-Álvarez
- Microbiology Section, Department of Molecular Biology, Faculty of Biology and Environmental Sciences, Vegazana Campus, University of León, León, 24071, Spain,
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21
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Klymyshin DO, Nimets OY, Stefanyshyn OM, Fedorenko VO. Heterologous expression of the lndYR and wblA gh genes in Streptomyces nogalater LV65, S. echinatus DSM40730, and S. peucetius subsp. Caesius ATCC27952 (producers of anthracycline antibiotics). CYTOL GENET+ 2013. [DOI: 10.3103/s0095452713040063] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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22
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Komatsu M, Komatsu K, Koiwai H, Yamada Y, Kozone I, Izumikawa M, Hashimoto J, Takagi M, Omura S, Shin-ya K, Cane DE, Ikeda H. Engineered Streptomyces avermitilis host for heterologous expression of biosynthetic gene cluster for secondary metabolites. ACS Synth Biol 2013; 2:384-96. [PMID: 23654282 PMCID: PMC3932656 DOI: 10.1021/sb3001003] [Citation(s) in RCA: 177] [Impact Index Per Article: 16.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
An industrial microorganism, Streptomyces avermitilis, which is a producer of anthelmintic macrocyclic lactones, avermectins, has been constructed as a versatile model host for heterologous expression of genes encoding secondary metabolite biosynthesis. Twenty of the entire biosynthetic gene clusters for secondary metabolites were successively cloned and introduced into a versatile model host S. avermitilis SUKA17 or 22. Almost all S. avermitilis transformants carrying the entire gene cluster produced metabolites as a result of the expression of biosynthetic gene clusters introduced. A few transformants were unable to produce metabolites, but their production was restored by the expression of biosynthetic genes using an alternative promoter or the expression of a regulatory gene in the gene cluster that controls the expression of biosynthetic genes in the cluster using an alternative promoter. Production of metabolites in some transformants of the versatile host was higher than that of the original producers, and cryptic biosynthetic gene clusters in the original producer were also expressed in a versatile host.
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Affiliation(s)
- Mamoru Komatsu
- Kitasato Institute for Life Sciences, Kitasato University, 1-15-1 Kitasato, Minami-ku, Sagamihara, Kanagawa 252-0373, Japan
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23
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Guo D, Zhao Y, Yang K. Coordination of glycerol utilization and clavulanic acid biosynthesis to improve clavulanic acid production in Streptomyces clavuligerus. SCIENCE CHINA-LIFE SCIENCES 2013; 56:591-600. [PMID: 23832248 DOI: 10.1007/s11427-013-4507-z] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/26/2013] [Accepted: 05/28/2013] [Indexed: 11/26/2022]
Abstract
The glycerol utilization (gyl) operon is involved in clavulanic acid (CA) production by Streptomyces clavuligerus, and possibly supplies the glyceraldehyde-3-phosphate (G3P) precursor for CA biosynthesis. The gyl operon is regulated by GylR and is induced by glycerol. To enhance CA production in S. clavuligerus, an extra copy of ccaR expressed from Pgyl (the gyl promoter) was integrated into the chromosome of S. clavuligerus NRRL 3585. This construct coordinated the transcription of CA biosynthetic pathway genes with expression of the gyl operon. In the transformants carrying the Pgyl-controlled regulatory gene ccaR, CA production was enhanced 3.19-fold in glycerol-enriched batch cultures, relative to the control strain carrying an extra copy of ccaR controlled by its own promoter (PccaR). Consistent with enhanced CA production, the transcription levels of ccaR, ceas2 and claR were significantly up-regulated in the transformants containing Pgyl-controlled ccaR.
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Affiliation(s)
- Dekun Guo
- School of Life Sciences, University of Science and Technology of China, Hefei 230027, China
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24
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Paradkar A. Clavulanic acid production by Streptomyces clavuligerus: biogenesis, regulation and strain improvement. J Antibiot (Tokyo) 2013; 66:411-20. [DOI: 10.1038/ja.2013.26] [Citation(s) in RCA: 50] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2013] [Revised: 02/25/2013] [Accepted: 03/11/2013] [Indexed: 11/09/2022]
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25
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Recent advances in the biosynthesis of penicillins, cephalosporins and clavams and its regulation. Biotechnol Adv 2013; 31:287-311. [DOI: 10.1016/j.biotechadv.2012.12.001] [Citation(s) in RCA: 99] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2012] [Revised: 11/30/2012] [Accepted: 12/01/2012] [Indexed: 11/23/2022]
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26
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Abstract
Microorganisms are one of the greatest sources of metabolic and enzymatic diversity. In recent years, emerging recombinant DNA and genomic techniques have facilitated the development of new efficient expression systems, modification of biosynthetic pathways leading to new metabolites by metabolic engineering, and enhancement of catalytic properties of enzymes by directed evolution. Complete sequencing of industrially important microbial genomes is taking place very rapidly and there are already hundreds of genomes sequenced. Functional genomics and proteomics are major tools used in the search for new molecules and development of higher-producing strains.
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27
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Biosynthesis of clavam metabolites. ACTA ACUST UNITED AC 2012; 39:1407-19. [DOI: 10.1007/s10295-012-1191-0] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2012] [Accepted: 08/22/2012] [Indexed: 01/06/2023]
Abstract
Abstract
Naturally occurring clavam metabolites include the valuable β-lactamase inhibitor, clavulanic acid, as well as stereochemical variants with side-chain modifications, called the 5S clavams. Because of the clinical importance of clavulanic acid, most studies of clavam biosynthesis are based on the industrial producer species Streptomyces clavuligerus. Well-characterized early steps in clavam biosynthesis are outlined, and less well understood late steps in 5S clavam biosynthesis are proposed. The complex genetic organization of the clavam biosynthetic genes in S. clavuligerus is described and, where possible, comparisons with other producer species are presented.
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28
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Martín JF, Liras P. Cascades and networks of regulatory genes that control antibiotic biosynthesis. Subcell Biochem 2012; 64:115-138. [PMID: 23080248 DOI: 10.1007/978-94-007-5055-5_6] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
Onset of the biosynthesis of bioactive secondary metabolites in batch cultures of actinomycetes occurs after the rapid growth phase, following a transition phase which involves complex metabolic changes. This transition is triggered by nutrient starvation or by other environmental stress signals. Expression of genes encoding bioactive secondary metabolites is governed by cascades of pathway specific regulators and networks of cross-talking global regulators. Pathway specific regulators such as Streptomyces antibiotic regulatory proteins, LAL-type and LysR-type regulators respond to autoregulatory proteins that act in concert with their cognate ligands (e.g. γ-butyrolactone receptor proteins and their cognate γ-butyrolactone ligands). Global regulators such as PhoR-PhoP and other two component systems and orphan response regulators, such as GlnR, control set of genes affecting primary and secondary metabolism. GlnR and, therefore, nitrogen metabolism genes are under phosphate control exerted by binding of PhoP to PHO boxes located in the promoter region of GlnR. A few pleiotropic regulatory genes, such as areB (ndgR), dmdR1 or dasR connect primary metabolism (amino acid biosynthesis, N-acetylglucosamine or iron levels) with antibiotic biosynthesis. Some atypical response regulators that require specific small ligands appear to be involved in feedback control of antibiotic production. All these mechanisms together modulate, in a coordinated manner, different aspects of Streptomyces metabolism as a real "protection net" that prevents drastic changes in metabolism that may be deleterious for cell survival.
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Affiliation(s)
- Juan F Martín
- Department of Molecular Biology, University of León, León, 24071, Spain,
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29
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Klimishin DA, Rabyk MV, Gren’ TP, Nimets’ OY, Gonchar MA, Gromyko AN, Fedorenko VA. Construction of Streptomyces nogalater Lv65 strains with enhanced nogalamicin biosynthesis using regulatory genes. APPL BIOCHEM MICRO+ 2011. [DOI: 10.1134/s0003683811060068] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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30
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Klymyshin DO, Gren’ TP, Fedorenko VO. Role of the snorA gene in nogalamycin biosynthesis by strain Streptomyces nogalater Lv65. Microbiology (Reading) 2011. [DOI: 10.1134/s0026261711040096] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
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31
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Seipke RF, Song L, Bicz J, Laskaris P, Yaxley AM, Challis GL, Loria R. The plant pathogen Streptomyces scabies 87-22 has a functional pyochelin biosynthetic pathway that is regulated by TetR- and AfsR-family proteins. MICROBIOLOGY-SGM 2011; 157:2681-2693. [PMID: 21757492 DOI: 10.1099/mic.0.047977-0] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Siderophores are high-affinity iron-chelating compounds produced by bacteria for iron uptake that can act as important virulence determinants for both plant and animal pathogens. Genome sequencing of the plant pathogen Streptomyces scabies 87-22 revealed the presence of a putative pyochelin biosynthetic gene cluster (PBGC). Liquid chromatography (LC)-MS analyses of culture supernatants of S. scabies mutants, in which expression of the cluster is upregulated and which lack a key biosynthetic gene from the cluster, indicated that pyochelin is a product of the PBGC. LC-MS comparisons with authentic standards on a homochiral stationary phase confirmed that pyochelin and not enantio-pyochelin (ent-pyochelin) is produced by S. scabies. Transcription of the S. scabies PBGC occurs via ~19 kb and ~3 kb operons and transcription of the ~19 kb operon is regulated by TetR- and AfsR-family proteins encoded by the cluster. This is the first report, to our knowledge, of pyochelin production by a Gram-positive bacterium; interestingly regulation of pyochelin production is distinct from characterized PBGCs in Gram-negative bacteria. Though pyochelin-mediated iron acquisition by Pseudomonas aeruginosa is important for virulence, in planta bioassays failed to demonstrate that pyochelin production by S. scabies is required for development of disease symptoms on excised potato tuber tissue or radish seedlings.
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Affiliation(s)
- Ryan F Seipke
- Department of Plant Pathology and Plant-Microbe Biology, Cornell University, Ithaca, NY 14853, USA
| | - Lijiang Song
- Department of Chemistry, University of Warwick, Coventry, UK
| | - Joanna Bicz
- Department of Chemistry, University of Warwick, Coventry, UK
| | - Paris Laskaris
- Department of Plant Pathology and Plant-Microbe Biology, Cornell University, Ithaca, NY 14853, USA
| | - Alice M Yaxley
- Department of Biological Sciences, University of Warwick, Coventry, UK
| | | | - Rosemary Loria
- Department of Plant Pathology and Plant-Microbe Biology, Cornell University, Ithaca, NY 14853, USA
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32
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Widdick DA, Hicks MG, Thompson BJ, Tschumi A, Chandra G, Sutcliffe IC, Brülle JK, Sander P, Palmer T, Hutchings MI. Dissecting the complete lipoprotein biogenesis pathway in Streptomyces scabies. Mol Microbiol 2011; 80:1395-412. [PMID: 21477129 DOI: 10.1111/j.1365-2958.2011.07656.x] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
Abstract
Following translocation, bacterial lipoproteins are lipidated by lipoprotein diacylglycerol transferase (Lgt) and cleaved of their signal peptides by lipoprotein signal peptidase (Lsp). In Gram-negative bacteria and mycobacteria, lipoproteins are further lipidated by lipoprotein N-acyl transferase (Lnt), to give triacylated lipoproteins. Streptomyces are unusual amongst Gram-positive bacteria because they export large numbers of lipoproteins via the twin arginine protein transport (Tat) pathway. Furthermore, some Streptomyces species encode two Lgt homologues and all Streptomyces species encode two homologues of Lnt. Here we characterize lipoprotein biogenesis in the plant pathogen Streptomyces scabies and report that lgt and lsp mutants are defective in growth and development while only moderately affected in virulence. Lipoproteins are lost from the membrane in an S. scabies lgt mutant but restored by expression of Streptomyces coelicolor lgt1 or lgt2 confirming that both encode functional Lgt enzymes. Furthermore, lipoproteins are N-acylated in Streptomyces with efficient N-acylation dependent on Lnt1 and Lnt2. However, deletion of lnt1 and lnt2 has no effect on growth, development or virulence. We thus present a detailed study of lipoprotein biogenesis in Streptomyces, the first study of Lnt function in a monoderm bacterium and the first study of bacterial lipoproteins as virulence factors in a plant pathogen.
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Affiliation(s)
- David A Widdick
- School of Biological Sciences, University of East Anglia, Norwich Research Park, Norwich, NR4 7TJ, UK
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Hojati Z, Salehi Z, Motovali-Bashi M, Korbekandi H, Jami S. Molecular Analysis of the Clavulanic Acid Regulatory Gene Isolated from an Iranian Strain of Streptomyces Clavuligerus , PTCC 1709. CELL JOURNAL 2011; 13:179-86. [PMID: 23508694 PMCID: PMC3584469] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/05/2011] [Accepted: 07/21/2011] [Indexed: 11/07/2022]
Abstract
OBJECTIVE The clavulanic acid regulatory gene (claR) is in the clavulanic acid biosynthetic gene cluster that encodes ClaR. This protein is a putative regulator of the late steps of clavulanic acid biosynthesis. The aim of this research is the molecular cloning of claR, isolated from the Iranian strain of Streptomyces clavuligerus (S. clavuligerus). MATERIALS AND METHODS In this experimental study, two different strains of S. clavuligerus were used (PTCC 1705 and DSM 738), of which there is no claR sequence record for strain PTCC 1705 in all three main gene banks. The specific designed primers were subjected to a few base modifications for introduction of the recognition sites of BamHI and ClaI. The claR gene was amplified by polymerase chain reaction (PCR) using DNA isolated from S. clavuligerus PTCC 1705. Nested-PCR, restriction fragment length polymorphism (PCR-RFLP), and sequencing were used for molecular analysis of the claR gene. The confirmed claR was subjected to double digestion with BamHI and ClaI. The cut claR was ligated into a pBluescript (pBs) vector and transformed into E. coli. RESULTS The entire sequence of the isolated claR (Iranian strain) was identified. The presence of the recombinant vector in the transformed colonies was confirmed by the colony-PCR procedure. The correct structure of the recombinant vector, isolated from the transformed E. coli, was confirmed using gel electrophoresis, PCR, and double digestion with restriction enzymes. CONCLUSION The constructed recombinant cassette, named pZSclaR, can be regarded as an appropriate tool for site directed mutagenesis and sub-cloning. At this time, claR has been cloned accompanied with its precisely selected promoter so it could be used in expression vectors. Hence the ClaR is known as a putative regulatory protein. The overproduced protein could also be used for other related investigations, such as a mobility shift assay.
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Affiliation(s)
- Zohreh Hojati
- 1. Department of Biology, Faculty of Sciences, University of Isfahan, Isfahan, Iran, * Corresponding Address: P.O. Box: 81746-7344 Biology Department, Faculty of Sciences, University of IsfahanIsfahan Iran
| | - Zahra Salehi
- 1. Department of Biology, Faculty of Sciences, University of Isfahan, Isfahan, Iran
| | - Majid Motovali-Bashi
- 1. Department of Biology, Faculty of Sciences, University of Isfahan, Isfahan, Iran
| | - Hasan Korbekandi
- 2. Department of Genetics and Molecular Biology, Faculty of Medicine, Medical University of Isfahan, Isfahan, Iran
| | - Saeed Jami
- 1. Department of Biology, Faculty of Sciences, University of Isfahan, Isfahan, Iran
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Bignell DRD, Seipke RF, Huguet-Tapia JC, Chambers AH, Parry RJ, Loria R. Streptomyces scabies 87-22 contains a coronafacic acid-like biosynthetic cluster that contributes to plant-microbe interactions. MOLECULAR PLANT-MICROBE INTERACTIONS : MPMI 2010; 23:161-75. [PMID: 20064060 DOI: 10.1094/mpmi-23-2-0161] [Citation(s) in RCA: 65] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
Plant-pathogenic Streptomyces spp. cause scab disease on economically important root and tuber crops, the most important of which is potato. Key virulence determinants produced by these species include the cellulose synthesis inhibitor, thaxtomin A, and the secreted Nec1 protein that is required for colonization of the plant host. Recently, the genome sequence of Streptomyces scabies 87-22 was completed, and a biosynthetic cluster was identified that is predicted to synthesize a novel compound similar to coronafacic acid (CFA), a component of the virulence-associated coronatine phytotoxin produced by the plant-pathogenic bacterium Pseudomonas syringae. Southern analysis indicated that the cfa-like cluster in S. scabies 87-22 is likely conserved in other strains of S. scabies but is absent from two other pathogenic streptomycetes, S. turgidiscabies and S. acidiscabies. Transcriptional analyses demonstrated that the cluster is expressed during plant-microbe interactions and that expression requires a transcriptional regulator embedded in the cluster as well as the bldA tRNA. A knockout strain of the biosynthetic cluster displayed a reduced virulence phenotype on tobacco seedlings compared with the wild-type strain. Thus, the cfa-like biosynthetic cluster is a newly discovered locus in S. scabies that contributes to host-pathogen interactions.
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Affiliation(s)
- Dawn R D Bignell
- Department of Plant Pathology and Plant-Microbe Biology, Cornell University, Ithaca, NY 14853, USA.
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Mackenzie AK, Valegård K, Iqbal A, Caines ME, Kershaw NJ, Jensen SE, Schofield CJ, Andersson I. Crystal Structures of an Oligopeptide-Binding Protein from the Biosynthetic Pathway of the β-Lactamase Inhibitor Clavulanic Acid. J Mol Biol 2010; 396:332-44. [DOI: 10.1016/j.jmb.2009.11.045] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2009] [Revised: 11/17/2009] [Accepted: 11/18/2009] [Indexed: 11/30/2022]
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Genome-minimized Streptomyces host for the heterologous expression of secondary metabolism. Proc Natl Acad Sci U S A 2010; 107:2646-51. [PMID: 20133795 DOI: 10.1073/pnas.0914833107] [Citation(s) in RCA: 368] [Impact Index Per Article: 26.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
To construct a versatile model host for heterologous expression of genes encoding secondary metabolite biosynthesis, the genome of the industrial microorganism Streptomyces avermitilis was systematically deleted to remove nonessential genes. A region of more than 1.4 Mb was deleted stepwise from the 9.02-Mb S. avermitilis linear chromosome to generate a series of defined deletion mutants, corresponding to 83.12-81.46% of the wild-type chromosome, that did not produce any of the major endogenous secondary metabolites found in the parent strain. The suitability of the mutants as hosts for efficient production of foreign metabolites was shown by heterologous expression of three different exogenous biosynthetic gene clusters encoding the biosynthesis of streptomycin (from S. griseus Institute for Fermentation, Osaka [IFO] 13350), cephamycin C (from S. clavuligerus American type culture collection (ATCC) 27064), and pladienolide (from S. platensis Mer-11107). Both streptomycin and cephamycin C were efficiently produced by individual transformants at levels higher than those of the native-producing species. Although pladienolide was not produced by a deletion mutant transformed with the corresponding intact biosynthetic gene cluster, production of the macrolide was enabled by introduction of an extra copy of the regulatory gene pldR expressed under control of an alternative promoter. Another mutant optimized for terpenoid production efficiently produced the plant terpenoid intermediate, amorpha-4,11-diene, by introduction of a synthetic gene optimized for Streptomyces codon usage. These findings highlight the strength and flexibility of engineered S. avermitilis as a model host for heterologous gene expression, resulting in the production of exogenous natural and unnatural metabolites.
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Adrio JL, Demain AL. Recombinant organisms for production of industrial products. Bioeng Bugs 2009; 1:116-31. [PMID: 21326937 DOI: 10.4161/bbug.1.2.10484] [Citation(s) in RCA: 86] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2009] [Revised: 10/30/2009] [Accepted: 11/02/2009] [Indexed: 11/19/2022] Open
Abstract
A revolution in industrial microbiology was sparked by the discoveries of ther double-stranded structure of DNA and the development of recombinant DNA technology. Traditional industrial microbiology was merged with molecular biology to yield improved recombinant processes for the industrial production of primary and secondary metabolites, protein biopharmaceuticals and industrial enzymes. Novel genetic techniques such as metabolic engineering, combinatorial biosynthesis and molecular breeding techniques and their modifications are contributing greatly to the development of improved industrial processes. In addition, functional genomics, proteomics and metabolomics are being exploited for the discovery of novel valuable small molecules for medicine as well as enzymes for catalysis. The sequencing of industrial microbal genomes is being carried out which bodes well for future process improvement and discovery of new industrial products.
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Affiliation(s)
- Jose-Luis Adrio
- NeuronBioPharma, S.A., Parque Tecnologico de Ciencias de la Salud, Edificio BIC, Armilla, Granada, Spain
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Application of a double-reporter-guided mutant selection method to improve clavulanic acid production in Streptomyces clavuligerus. Metab Eng 2009; 11:310-8. [DOI: 10.1016/j.ymben.2009.06.003] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2009] [Revised: 06/14/2009] [Accepted: 06/29/2009] [Indexed: 11/23/2022]
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Chapter 16. Enzymology of beta-lactam compounds with cephem structure produced by actinomycete. Methods Enzymol 2009; 458:401-29. [PMID: 19374992 DOI: 10.1016/s0076-6879(09)04816-2] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/30/2023]
Abstract
Cephamycins are beta-lactam antibiotics with a cephem structure produced by actinomycetes. They are synthesized by a pathway similar to that of cephalosporin C in filamentous fungi but the actinomycetes pathway contains additional enzymes for the formation of the alpha-aminoadipic acid (AAA) precursor and for the final steps specific to cephemycins. Most of the biochemical and genetic studies on cephemycins have been made on cephemycin C biosynthesis in the producer strains Streptomyces clavuligerus ATCC27064 and Amycolatopsis lactamdurans NRRL3802. Genes encoding cephamycin C biosynthetic enzymes are clustered in both actinomycetes. Ten enzymatic steps are involved in the formation of cephamycin C. The precursor alpha-AAA is formed by the sequential action of lysine-6-aminotransferase and piperideine-6-carboxylate dehydrogenase. Steps common to cephalosporin C biosynthesis include the formation of the tripeptide L-delta-alpha-aminoadipyl-L-cysteinyl-D-valine (ACV) by ACV synthetase, the cyclization of ACV to form isopenicillin N (IPN) by IPN synthase, the epimerization of IPN to penicillin N by isopenicillin N epimerase, the ring expansion of penicillin N to a six member cephem ring by deacetoxycephalosporin C synthase (DAOCS) and the hydroxylation at C-3' by deacetylcephalosporin C hydroxylase. However, in actinomycetes, the epimerization step is different from that in cephalosporin-producing fungi, and the expansion of the ring and its hydroxylation are performed by separate enzymes. Specific steps in cephamycin biosynthesis include the carbamoylation at C-3' by cephem carbamoyl transferase and the introduction of a methoxyl group at C-7 by the joint action of a C-7 cephem-hydroxylase and a methyltransferase. All the enzymes of the pathway have been purified almost to homogeneity and the DAOC synthase and 7-hydroxycephem-methyltransferase (CmcI) of S. clavuligerus have been crystallized giving insights into the mode of action of these enzymes. The cefE gene of S. clavuligerus, encoding DAOCS, has been extensively used to expand the penicillin ring in filamentous fungi in vivo using DNA recombinant technology.
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BldG and SCO3548 interact antagonistically to control key developmental processes in Streptomyces coelicolor. J Bacteriol 2009; 191:2541-50. [PMID: 19201788 DOI: 10.1128/jb.01695-08] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The similarity of BldG and the downstream coexpressed protein SCO3548 to anti-anti-sigma and anti-sigma factors, respectively, together with the phenotype of a bldG mutant, suggests that BldG and SCO3548 interact as part of a regulatory system to control both antibiotic production and morphological differentiation in Streptomyces coelicolor. A combination of bacterial two-hybrid, affinity purification, and far-Western analyses demonstrated that there was self-interaction of both BldG and SCO3548, as well as a direct interaction between the two proteins. Furthermore, a genetic complementation experiment demonstrated that SCO3548 antagonizes the function of BldG, similar to other anti-anti-sigma/anti-sigma factor pairs. It is therefore proposed that BldG and SCO3548 form a partner-switching pair that regulates the function of one or more sigma factors in S. coelicolor. The conservation of bldG and sco3548 in other streptomycetes demonstrates that this system is likely a key regulatory switch controlling developmental processes throughout the genus Streptomyces.
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Seipke RF, Loria R. Streptomyces scabies 87-22 possesses a functional tomatinase. J Bacteriol 2008; 190:7684-92. [PMID: 18835993 PMCID: PMC2583622 DOI: 10.1128/jb.01010-08] [Citation(s) in RCA: 49] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2008] [Accepted: 09/22/2008] [Indexed: 11/20/2022] Open
Abstract
The actinomycete Streptomyces scabies 87-22 is the causal agent of common scab, an economically important disease of potato and taproot crops. Sequencing of the S. scabies 87-22 genome revealed the presence of a gene with high homology to the gene encoding the alpha-tomatine-detoxifying enzyme tomatinase found in fungal tomato pathogens. The tomA gene from S. scabies 87-22 was cotranscribed with a putative family 1 glycosyl hydrolase gene, and purified TomA protein was active only on alpha-tomatine and not potato glycoalkaloids or xylans. Tomatinase-null mutants were more sensitive to alpha-tomatine than the wild-type strain in a disk diffusion assay. Interestingly, tomatine affected only aerial mycelium and not vegetative mycelium, suggesting that the target(s) of alpha-tomatine is not present during vegetative growth. Severities of disease for tomato seedlings affected by S. scabies 87-22 wild-type and DeltatomA1 strains were indistinguishable, suggesting that tomatinase is not important in pathogenicity on tomato plants. However, conservation of tomA on a pathogenicity island in S. acidiscabies and S. turgidiscabies suggests a role in plant-microbe interaction.
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Affiliation(s)
- Ryan F Seipke
- Department of Plant Pathology, Cornell University, 334 Plant Science Building, Ithaca, NY 14853, USA
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Gomez-Escribano JP, Martín JF, Hesketh A, Bibb MJ, Liras P. Streptomyces clavuligerus relA-null mutants overproduce clavulanic acid and cephamycin C: negative regulation of secondary metabolism by (p)ppGpp. MICROBIOLOGY-SGM 2008; 154:744-755. [PMID: 18310021 DOI: 10.1099/mic.0.2007/011890-0] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
The (p)ppGpp synthetase gene, relA, of Streptomyces clavuligerus was cloned, sequenced and shown to be located in a genomic region that is highly conserved in other Streptomyces species. relA-disrupted and relA-deleted mutants of S. clavuligerus were constructed, and both were unable to form aerial mycelium or to sporulate, but regained these abilities when complemented with wild-type relA. Neither ppGpp nor pppGpp was detected in the S. clavuligerus relA-deletion mutant. In contrast to another study, clavulanic acid and cephamycin C production increased markedly in the mutants compared to the wild-type strain; clavulanic acid production increased three- to fourfold, while that of cephamycin C increased about 2.5-fold. Complementation of the relA-null mutants with wild-type relA decreased antibiotic yields to approximately wild-type levels. Consistent with these observations, transcription of genes involved in clavulanic acid (ceaS2) or cephamycin C (cefD) production increased dramatically in the relA-deleted mutant when compared to the wild-type strain. These results are entirely consistent with the growth-associated production of both cephamycin C and clavulanic acid, and demonstrate, apparently for the first time, negative regulation of secondary metabolite biosynthesis by (p)ppGpp in a Streptomyces species of industrial interest.
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Affiliation(s)
- Juan P Gomez-Escribano
- Área de Microbiología, Facultad de Ciencias Biológicas y Ambientales, Universidad de León, Campus de Vegazana s/n, 24071 León, Spain
| | - Juan F Martín
- Instituto de Biotecnología (INBIOTEC), Parque Científico de León, Av. Real 1, 24006 León, Spain.,Área de Microbiología, Facultad de Ciencias Biológicas y Ambientales, Universidad de León, Campus de Vegazana s/n, 24071 León, Spain
| | - A Hesketh
- Department of Molecular Microbiology, John Innes Centre, Colney Lane, Norwich NR4 7UH, UK
| | - M J Bibb
- Department of Molecular Microbiology, John Innes Centre, Colney Lane, Norwich NR4 7UH, UK
| | - P Liras
- Instituto de Biotecnología (INBIOTEC), Parque Científico de León, Av. Real 1, 24006 León, Spain.,Área de Microbiología, Facultad de Ciencias Biológicas y Ambientales, Universidad de León, Campus de Vegazana s/n, 24071 León, Spain
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Regulatory mechanisms controlling antibiotic production in Streptomyces clavuligerus. J Ind Microbiol Biotechnol 2008; 35:667-76. [DOI: 10.1007/s10295-008-0351-8] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/29/2008] [Accepted: 03/31/2008] [Indexed: 11/25/2022]
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Joshi M, Rong X, Moll S, Kers J, Franco C, Loria R. Streptomyces turgidiscabies secretes a novel virulence protein, Nec1, which facilitates infection. MOLECULAR PLANT-MICROBE INTERACTIONS : MPMI 2007; 20:599-608. [PMID: 17555268 DOI: 10.1094/mpmi-20-6-0599] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/15/2023]
Abstract
Emergence of new, economically important plant-pathogenic species in the mostly saprophytic genus Streptomyces involves acquisition of a large, mobile pathogenicity island (PAI). Biosynthetic genes for a phytotoxin, thaxtomin A, are contained on this PAI. The Nec1 protein has necrogenic activity on excised potato tuber tissue, and the encoding gene is highly conserved in plant-pathogenic Streptomyces spp. The G+C content of nec1 indicates lateral transfer from an unrelated taxon; however, the nucleic acid and protein databases have not yielded homologs. Data presented in this article demonstrate that the Nec1 protein is necrogenic when expressed in Escherichia coli and that an active 16-kDa form of Nec1 is secreted from the plant pathogen Streptomyces turgidiscabies. Deletion analysis of nec1 demonstrated that the 151-amino-acid C-terminal region of the Nec1 protein is sufficient to confer necrogenic activity. Analysis of nec1 transcriptional start sites indicates that two mRNA species are produced and that the site of transcription initiation is influenced by glucose. S. turgidiscabies containing a nec1 deletion was greatly compromised in virulence on Arabidopsis thaliana, Nicotiana tabacum, and Raphanus sativus seedlings. The wild-type strain, S. turgidiscabies Car8, aggressively colonized and infected the root meristem of radish, whereas the deltanec1 mutant Car811 did not. Taken together, these data suggest that Nec1 is a secreted virulence protein with a conserved plant cell target that acts early in plant infection.
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Affiliation(s)
- Madhumita Joshi
- Department of Plant Pathology, Cornell University, Ithaca, NY 14853-5904, USA
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Gomez-Escribano JP, Liras P, Pisabarro A, Martín JF. An rplKDelta29-PALG-32 mutation leads to reduced expression of the regulatory genes ccaR and claR and very low transcription of the ceaS2 gene for clavulanic acid biosynthesis in Streptomyces clavuligerus. Mol Microbiol 2006; 61:758-70. [PMID: 16803595 DOI: 10.1111/j.1365-2958.2006.05266.x] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
Abstract
The transcriptional and translational control of the biosynthesis of the beta-lactamase inhibitor clavulanic acid is a subject of great scientific and industrial interest. To study the role of the ribosomal protein L11 on control of clavulanic acid gene transcription, the DNA region aspC-tRNA(trp)-secE-rplK-rplA-rplJ-rplL of Streptomyces clavuligerus was cloned and characterized. An S. clavuligerus rplK(DeltaPALG) mutant, with an internal 12 nucleotides in-frame deletion in the rplK gene, encoding the L11 (RplK) ribosomal protein lacking amino acids (29)PALG(32), was constructed by gene replacement. This deletion alters the L11 N-terminal domain that interacts with the RelA and class I releasing factors-mediated translational termination. The mutant grew well, showed threefold higher resistance to thiostrepton, did not form spores and lacked diffusible brown pigments, as compared with the wild-type strain. The wild-type phenotype was recovered by complementation with the native rplK gene. S. clavuligerus rplK(DeltaPALG) produced reduced levels of clavulanic acid (15-26% as compared with the wild type) and cephamycin C (40-50%) in cultures grown in defined SA and complex TSB media. The decreased yields resulted from an impaired transcription of the regulatory genes ccaR and claR and the cefD and ceaS2 genes for cephamycin and clavulanic acid biosynthesis respectively. Expression of ceaS2 encoding carboxyethylarginine synthase (CEAS), the precursor-committing enzyme for clavulanic acid biosynthesis, was particularly affected in this mutant. In the wild-type strain polyphosphorylated nucleotides peaked at 36-48 h of growth in SA cultures whereas expression of the cephamycin and clavulanic acid genes occurred 12-24 h earlier than the increase in ppGpp indicating that there is no strict correlation between the peak of ppGpp and the onset of transcription of the clavulanic acid and cephamycin C biosynthesis. The drastic effect of the rplK(DeltaPALG) mutation on the onset of expression of the ceaS2 and the regulatory ccaR and claR genes and the lack of correlation with ppGpp levels suggest that the onset of transcription of these genes is modulated by the conformational alteration of the N-terminal region of L11 probably by interaction with the nascent peptide releasing factors and with RelA.
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Affiliation(s)
- Juan Pablo Gomez-Escribano
- Area de Microbiología, Facultad de Ciencias Biológicas y Ambientales, Universidad de León, Campus de Vegazana, s/n, 24071 León, Spain
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