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Jiang Y, Wang K, Xu L, Xu L, Xu Q, Mu Y, Hong Q, He J, Jiang J, Qiu J. DipR, a GntR/FadR-family transcriptional repressor: regulatory mechanism and widespread distribution of the dip cluster for dipicolinic acid catabolism in bacteria. Nucleic Acids Res 2024; 52:10951-10964. [PMID: 39180394 PMCID: PMC11472048 DOI: 10.1093/nar/gkae728] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2024] [Revised: 08/07/2024] [Accepted: 08/09/2024] [Indexed: 08/26/2024] Open
Abstract
Dipicolinic acid is an essential component of bacterial spores for stress resistance, which is released into the environment after spore germination. In a previous study, a dip gene cluster was found to be responsible for the catabolism of dipicolinic acid in Alcaligenes faecalis JQ135. However, the transcriptional regulatory mechanism remains unclear. The present study characterized the new GntR/FadR family transcriptional factor DipR, showing that the dip cluster is transcribed as the six transcriptional units, dipR, dipA, dipBC, dipDEFG, dipH and dipJKLM. The purified DipR protein has six binding sites sharing the 6-bp conserved motif sequence 5'-GWATAC-3'. Site-directed mutations indicated that these motif sequences are essential for DipR binding. Moreover, the four key amino acid residues R63, R67, H196 and H218 of DipR, examined by site-directed mutagenesis, played crucial roles in DipR regulation. Bioinformatics analysis showed that dip clusters including dipR genes are widely distributed in bacteria, are taxon-related, and co-evolved with their hosts. This paper provides new insights into the transcriptional regulatory mechanism of dipicolinic acid degradation by DipR in bacteria.
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Affiliation(s)
- Yinhu Jiang
- Key Laboratory of Agricultural and Environmental Microbiology, Ministry of Agriculture and Rural Affairs, College of Life Sciences, Nanjing Agricultural University, Nanjing 210095, China
| | - Kexin Wang
- Key Laboratory of Agricultural and Environmental Microbiology, Ministry of Agriculture and Rural Affairs, College of Life Sciences, Nanjing Agricultural University, Nanjing 210095, China
| | - Lu Xu
- Key Laboratory of Agricultural and Environmental Microbiology, Ministry of Agriculture and Rural Affairs, College of Life Sciences, Nanjing Agricultural University, Nanjing 210095, China
| | - Lanyi Xu
- Key Laboratory of Agricultural and Environmental Microbiology, Ministry of Agriculture and Rural Affairs, College of Life Sciences, Nanjing Agricultural University, Nanjing 210095, China
| | - Qimiao Xu
- Key Laboratory of Agricultural and Environmental Microbiology, Ministry of Agriculture and Rural Affairs, College of Life Sciences, Nanjing Agricultural University, Nanjing 210095, China
| | - Yang Mu
- Taizhou Center for Disease Prevention and Control, Taizhou 225300, China
| | - Qing Hong
- Key Laboratory of Agricultural and Environmental Microbiology, Ministry of Agriculture and Rural Affairs, College of Life Sciences, Nanjing Agricultural University, Nanjing 210095, China
| | - Jian He
- Key Laboratory of Agricultural and Environmental Microbiology, Ministry of Agriculture and Rural Affairs, College of Life Sciences, Nanjing Agricultural University, Nanjing 210095, China
| | - Jiandong Jiang
- Key Laboratory of Agricultural and Environmental Microbiology, Ministry of Agriculture and Rural Affairs, College of Life Sciences, Nanjing Agricultural University, Nanjing 210095, China
| | - Jiguo Qiu
- Key Laboratory of Agricultural and Environmental Microbiology, Ministry of Agriculture and Rural Affairs, College of Life Sciences, Nanjing Agricultural University, Nanjing 210095, China
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Yang H, Gao J, Peng X, Han Y. Application of synthetic biology strategies to promote biosynthesis of fatty acids and their derivatives. ADVANCES IN APPLIED MICROBIOLOGY 2024; 128:83-104. [PMID: 39059844 DOI: 10.1016/bs.aambs.2024.05.002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/28/2024]
Abstract
Fatty acids and their derivatives are indispensable biomolecules in all organisms, and can be used as intermediates in the synthesis of pharmaceuticals, biofuels and pesticides, and thus their demand has increased dramatically in recent years. In addition to serving as structural components of cell membranes and metabolic energy, fatty acids and their derivatives can also be used as signal transduction and regulatory bioactive molecules to regulate cell functions. Biosynthesis of fatty acids and their derivatives through microbial catalysis provides green and alternative options to meet the goal. However, the low biosynthetic titer of fatty acids and their derivatives limits their industrial production and application. In this review, we first summarize the metabolic pathways and related enzymes of fatty acids and their derivatives biosynthesis. Then, the strategies and research progress of biosynthesis of fatty acids and derivatives through metabolic and enzyme engineering were reviewed. The biosynthesis of saturated fatty acids (medium chain fatty acids and long chain fatty acids), bioactive fatty acids (PUFAs, oxylipins, ether lipids), and their derivatives with microbial and enzymatic catalysis were respectively summarized. Finally, synthetic biology strategies to improve fatty acids and their derivatives production through enzyme rational design, carbon metabolism flux, cofactors balance, and metabolic pathways design were discussed. The review provides references and prospects for fatty acids and their derivatives biosynthesis and industrial production.
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Affiliation(s)
- Haiqian Yang
- National Key Laboratory of Biochemical Engineering, Institute of Process Engineering, Chinese Academy of Sciences, Beijing, P.R. China; Key Laboratory of Biopharmaceutical Preparation and Delivery, Chinese Academy of Sciences, Beijing, P.R. China; School of Chemical Engineering, University of Chinese Academy of Sciences, Beijing, P.R. China
| | - Jie Gao
- Department of Cardiovascular Surgery, Beijing Anzhen Hospital, Capital Medical University, Beijing, P.R. China
| | - Xiaowei Peng
- National Key Laboratory of Biochemical Engineering, Institute of Process Engineering, Chinese Academy of Sciences, Beijing, P.R. China; Key Laboratory of Biopharmaceutical Preparation and Delivery, Chinese Academy of Sciences, Beijing, P.R. China; School of Chemical Engineering, University of Chinese Academy of Sciences, Beijing, P.R. China
| | - Yejun Han
- National Key Laboratory of Biochemical Engineering, Institute of Process Engineering, Chinese Academy of Sciences, Beijing, P.R. China; Key Laboratory of Biopharmaceutical Preparation and Delivery, Chinese Academy of Sciences, Beijing, P.R. China; School of Chemical Engineering, University of Chinese Academy of Sciences, Beijing, P.R. China.
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Stanley HM, Trent MS. Loss of YhcB results in overactive fatty acid biosynthesis. mBio 2024; 15:e0079024. [PMID: 38742872 PMCID: PMC11237625 DOI: 10.1128/mbio.00790-24] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2024] [Accepted: 04/05/2024] [Indexed: 05/16/2024] Open
Abstract
Loss of the Escherichia coli inner membrane protein YhcB results in pleomorphic cell morphology and clear growth defects. Prior work suggested that YhcB was directly involved in cell division or peptidoglycan assembly. We found that loss of YhcB is detrimental in genetic backgrounds in which lipopolysaccharide (LPS) or glycerophospholipid (GPL) synthesis is altered. The growth defect of ΔyhcB could be rescued through inactivation of the Mla pathway, a system responsible for the retrograde transport of GPLs that are mislocalized to the outer leaflet of the outer membrane. Interestingly, this rescue was dependent upon the outer membrane phospholipase PldA that cleaves GPLs at the bacterial surface. Since the freed fatty acids resulting from PldA activity serve as a signal to the cell to increase LPS synthesis, this result suggested that outer membrane lipids are imbalanced in ΔyhcB. Mutations that arose in ΔyhcB populations during two independent suppressor screens were in genes encoding subunits of the acetyl coenzyme A carboxylase complex, which initiates fatty acid biosynthesis (FAB). These mutations fully restored cell morphology and reduced GPL levels, which were increased compared to wild-type bacteria. Growth of ΔyhcB with the FAB-targeting antibiotic cerulenin also increased cellular fitness. Furthermore, genetic manipulation of FAB and lipid biosynthesis showed that decreasing FAB rescued ΔyhcB filamentation, whereas increasing LPS alone could not. Altogether, these results suggest that YhcB may play a pivotal role in regulating FAB and, in turn, impact cell envelope assembly and cell division.IMPORTANCESynthesis of the Gram-negative cell envelope is a dynamic and complex process that entails careful coordination of many biosynthetic pathways. The inner and outer membranes are composed of molecules that are energy intensive to synthesize, and, accordingly, these synthetic pathways are under tight regulation. The robust nature of the Gram-negative outer membrane renders it naturally impermeable to many antibiotics and therefore a target of interest for antimicrobial design. Our data indicate that when the inner membrane protein YhcB is absent in Escherichia coli, the pathway for generating fatty acid substrates needed for all membrane lipid synthesis is dysregulated which leads to increased membrane material. These findings suggest a potentially novel regulatory mechanism for controlling the rate of fatty acid biosynthesis.
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Affiliation(s)
- Hannah M Stanley
- Department of Microbiology, College of Art and Sciences, University of Georgia, Athens, Georgia, USA
| | - M Stephen Trent
- Department of Microbiology, College of Art and Sciences, University of Georgia, Athens, Georgia, USA
- Department of Infectious Diseases, College of Veterinary Medicine, University of Georgia, Athens, Georgia, USA
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Cronan JE. Unsaturated fatty acid synthesis in bacteria: Mechanisms and regulation of canonical and remarkably noncanonical pathways. Biochimie 2024; 218:137-151. [PMID: 37683993 PMCID: PMC10915108 DOI: 10.1016/j.biochi.2023.09.007] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2023] [Revised: 08/02/2023] [Accepted: 09/04/2023] [Indexed: 09/10/2023]
Abstract
Unsaturated phospholipid acyl chains are required for membrane function in most bacteria. The double bonds of the cis monoenoic chains arise by two distinct pathways depending on whether oxygen is required. The oxygen-independent pathway (traditionally called the anaerobic pathway) introduces the cis double bond by isomerization of the trans double bond intermediate of the fatty acid elongation cycle. Double bond isomerization occurs at an intermediate chain length (e.g., C10) and the isomerization product is elongated to the C16-C18 chains that become phospholipid monoenoic acyl chains. This pathway was first delineated in Escherichia coli and became the paradigm pathway. However, studies of other bacteria show deviations from this paradigm, the most exceptional being reversal of the fatty acid elongation cycle by a reaction paralleling the initial step in the β-oxidative degradation of fatty acids. In the oxygen-dependent pathway diiron enzymes called desaturases introduce a double bond into a saturated acyl chain by regioselective cis dehydrogenation through activation of molecular oxygen with an active-site diiron cluster. This difficult hydrogen abstraction from a methylene group often occurs at the midpoint of a saturated fatty acyl chain. In bacteria the acyl chain is a phospholipid acyl chain, and the desaturase is membrane bound. Both the oxygen-independent oxygen-dependent pathways are transcriptionally regulated by repressor and activator proteins that respond to small molecule ligands such as acyl-CoAs. However, in Bacillus subtilis the desaturase is synthesized only at low growth temperatures, a process controlled by a signal transduction regulatory pathway dependent on membrane lipid properties.
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Affiliation(s)
- John E Cronan
- Departments of Microbiology and Biochemistry, University of Illinois, Urbana, 61801, USA.
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Schiaffi V, Barras F, Bouveret E. Matching the β-oxidation gene repertoire with the wide diversity of fatty acids. Curr Opin Microbiol 2024; 77:102402. [PMID: 37992547 DOI: 10.1016/j.mib.2023.102402] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2023] [Revised: 10/23/2023] [Accepted: 10/28/2023] [Indexed: 11/24/2023]
Abstract
Bacteria can use fatty acids (FAs) from their environment as carbon and energy source. This catabolism is performed by the enzymes of the well-known β-oxidation machinery, producing reducing power and releasing acetyl-CoA that can feed the tricarboxylic acid cycle. FAs are extremely diverse: they can be saturated or (poly)unsaturated and are found in different sizes. The need to degrade such a wide variety of compounds may explain why so many seemingly homologous enzymes are found for each step of the β-oxidation cycle. In addition, the degradation of unsaturated fatty acids requires specific auxiliary enzymes for isomerase and reductase reactions. Furthermore, the β-oxidation cycle can be blocked by dead-end products, which are taken care of by acyl-CoA thioesterases. Yet, the functional characterization of the enzymes required for the degradation of the full diversity of FAs remains to be documented in most bacteria.
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Affiliation(s)
- Veronica Schiaffi
- Institut Pasteur, Department of Microbiology, Université Paris-Cité, UMR CNRS 6047, SAMe Unit, France
| | - Frédéric Barras
- Institut Pasteur, Department of Microbiology, Université Paris-Cité, UMR CNRS 6047, SAMe Unit, France
| | - Emmanuelle Bouveret
- Institut Pasteur, Department of Microbiology, Université Paris-Cité, UMR CNRS 6047, SAMe Unit, France.
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Zhu Q, Bai X, Li Q, Zhang M, Hu G, Pan K, Liu H, Ke Z, Hong Q, Qiu J. PcaR, a GntR/FadR Family Transcriptional Repressor Controls the Transcription of Phenazine-1-Carboxylic Acid 1,2-Dioxygenase Gene Cluster in Sphingomonas histidinilytica DS-9. Appl Environ Microbiol 2023; 89:e0212122. [PMID: 37191535 PMCID: PMC10304782 DOI: 10.1128/aem.02121-22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2022] [Accepted: 04/29/2023] [Indexed: 05/17/2023] Open
Abstract
In our previous study, the phenazine-1-carboxylic acid (PCA) 1,2-dioxygenase gene cluster (pcaA1A2A3A4 cluster) in Sphingomonas histidinilytica DS-9 was identified to be responsible for the conversion of PCA to 1,2-dihydroxyphenazine (Ren Y, Zhang M, Gao S, Zhu Q, et al. 2022. Appl Environ Microbiol 88:e00543-22). However, the regulatory mechanism of the pcaA1A2A3A4 cluster has not been elucidated yet. In this study, the pcaA1A2A3A4 cluster was found to be transcribed as two divergent operons: pcaA3-ORF5205 (named A3-5205 operon) and pcaA1A2-ORF5208-pcaA4-ORF5210 (named A1-5210 operon). The promoter regions of the two operons were overlapped. PcaR acts as a transcriptional repressor of the pcaA1A2A3A4 cluster, and it belongs to GntR/FadR family transcriptional regulator. Gene disruption of pcaR can shorten the lag phase of PCA degradation. The results of electrophoretic mobility shift assay and DNase I footprinting showed that PcaR binds to a 25-bp motif in the ORF5205-pcaA1 intergenic promoter region to regulate the expression of two operons. The 25-bp motif covers the -10 region of the promoter of A3-5205 operon and the -35 region and -10 region of the promoter of A1-5210 operon. The TNGT/ANCNA box within the motif was essential for PcaR binding to the two promoters. PCA acted as an effector of PcaR, preventing it from binding to the promoter region and repressing the transcription of the pcaA1A2A3A4 cluster. In addition, PcaR represses its own transcription, and this repression can be relieved by PCA. This study reveals the regulatory mechanism of PCA degradation in strain DS-9, and the identification of PcaR increases the variety of regulatory model of the GntR/FadR-type regulator. IMPORTANCE Sphingomonas histidinilytica DS-9 is a phenazine-1-carboxylic acid (PCA)-degrading strain. The 1,2-dioxygenase gene cluster (pcaA1A2A3A4 cluster, encoding dioxygenase PcaA1A2, reductase PcaA3, and ferredoxin PcaA4) is responsible for the initial degradation step of PCA and widely distributed in Sphingomonads, but its regulatory mechanism has not been investigated yet. In this study, a GntR/FadR-type transcriptional regulator PcaR repressing the transcription of pcaA1A2A3A4 cluster and pcaR gene was identified and characterized. The binding site of PcaR in ORF5205-pcaA1 intergenic promoter region contains a TNGT/ANCNA box, which is important for the binding. These findings enhance our understanding of the molecular mechanism of PCA degradation.
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Affiliation(s)
- Qian Zhu
- Key Laboratory of Agricultural and Environmental Microbiology, Ministry of Agriculture and Rural Affairs, College of Life Sciences, Nanjing Agricultural University, Nanjing, Jiangsu, People’s Republic of China
| | - Xuekun Bai
- Key Laboratory of Agricultural and Environmental Microbiology, Ministry of Agriculture and Rural Affairs, College of Life Sciences, Nanjing Agricultural University, Nanjing, Jiangsu, People’s Republic of China
| | - Qian Li
- Key Laboratory of Agricultural and Environmental Microbiology, Ministry of Agriculture and Rural Affairs, College of Life Sciences, Nanjing Agricultural University, Nanjing, Jiangsu, People’s Republic of China
| | - Mingliang Zhang
- Key Laboratory of Agricultural and Environmental Microbiology, Ministry of Agriculture and Rural Affairs, College of Life Sciences, Nanjing Agricultural University, Nanjing, Jiangsu, People’s Republic of China
| | - Gang Hu
- Key Laboratory of Agricultural and Environmental Microbiology, Ministry of Agriculture and Rural Affairs, College of Life Sciences, Nanjing Agricultural University, Nanjing, Jiangsu, People’s Republic of China
| | - Kaihua Pan
- Key Laboratory of Agricultural and Environmental Microbiology, Ministry of Agriculture and Rural Affairs, College of Life Sciences, Nanjing Agricultural University, Nanjing, Jiangsu, People’s Republic of China
| | - Hongfei Liu
- Key Laboratory of Agricultural and Environmental Microbiology, Ministry of Agriculture and Rural Affairs, College of Life Sciences, Nanjing Agricultural University, Nanjing, Jiangsu, People’s Republic of China
| | - Zhijian Ke
- School of Biological and Chemical Engineering, Ningbo Tech University, Ningbo, Zhejiang, People’s Republic of China
| | - Qing Hong
- Key Laboratory of Agricultural and Environmental Microbiology, Ministry of Agriculture and Rural Affairs, College of Life Sciences, Nanjing Agricultural University, Nanjing, Jiangsu, People’s Republic of China
| | - Jiguo Qiu
- Key Laboratory of Agricultural and Environmental Microbiology, Ministry of Agriculture and Rural Affairs, College of Life Sciences, Nanjing Agricultural University, Nanjing, Jiangsu, People’s Republic of China
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Meng Q, Xu Q, Xu Y, Ren H, Ge X, Yu J, Cao X, Yin J, Yu Z. A FadR-Type Regulator Activates the Biodegradation of Polycyclic Aromatic Hydrocarbons by Mediating Quorum Sensing in Croceicoccus naphthovorans Strain PQ-2. Appl Environ Microbiol 2023; 89:e0043323. [PMID: 37098893 PMCID: PMC10231186 DOI: 10.1128/aem.00433-23] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2023] [Accepted: 04/04/2023] [Indexed: 04/27/2023] Open
Abstract
Bacteria employ multiple transcriptional regulators to orchestrate cellular responses to adapt to constantly varying environments. The bacterial biodegradation of polycyclic aromatic hydrocarbons (PAHs) has been extensively described, and yet, the PAH-related transcriptional regulators remain elusive. In this report, we identified an FadR-type transcriptional regulator that controls phenanthrene biodegradation in Croceicoccus naphthovorans strain PQ-2. The expression of fadR in C. naphthovorans PQ-2 was induced by phenanthrene, and its deletion significantly impaired both the biodegradation of phenanthrene and the synthesis of acyl-homoserine lactones (AHLs). In the fadR deletion strain, the biodegradation of phenanthrene could be recovered by supplying either AHLs or fatty acids. Notably, FadR simultaneously activated the fatty acid biosynthesis pathway and repressed the fatty acid degradation pathway. As intracellular AHLs are synthesized with fatty acids as substrates, boosting the fatty acid supply could enhance AHL synthesis. Collectively, these findings demonstrate that FadR in C. naphthovorans PQ-2 positively regulates PAH biodegradation by controlling the formation of AHLs, which is mediated by the metabolism of fatty acids. IMPORTANCE Master transcriptional regulation of carbon catabolites is extremely important for the survival of bacteria that face changes in carbon sources. Polycyclic aromatic hydrocarbons (PAHs) can be utilized as carbon sources by some bacteria. FadR is a well-known transcriptional regulator involved in fatty acid metabolism; however, the connection between FadR regulation and PAH utilization in bacteria remains unknown. This study revealed that a FadR-type regulator in Croceicoccus naphthovorans PQ-2 stimulated PAH biodegradation by controlling the biosynthesis of the acyl-homoserine lactone quorum-sensing signals that belong to fatty acid-derived compounds. These results provide a unique perspective for understanding bacterial adaptation to PAH-containing environments.
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Affiliation(s)
- Qiu Meng
- College of Biotechnology and Bioengineering, Zhejiang University of Technology, Hangzhou, Zhejiang Province, China
| | - Qimiao Xu
- College of Biotechnology and Bioengineering, Zhejiang University of Technology, Hangzhou, Zhejiang Province, China
| | - Yinming Xu
- College of Biotechnology and Bioengineering, Zhejiang University of Technology, Hangzhou, Zhejiang Province, China
| | - Huiping Ren
- College of Biotechnology and Bioengineering, Zhejiang University of Technology, Hangzhou, Zhejiang Province, China
| | - Xuzhe Ge
- College of Biotechnology and Bioengineering, Zhejiang University of Technology, Hangzhou, Zhejiang Province, China
| | - Jianming Yu
- College of Environment, Zhejiang University of Technology, Hangzhou, Zhejiang Province, China
| | - Xueqiang Cao
- College of Biotechnology and Bioengineering, Zhejiang University of Technology, Hangzhou, Zhejiang Province, China
| | - Jianhua Yin
- College of Biotechnology and Bioengineering, Zhejiang University of Technology, Hangzhou, Zhejiang Province, China
| | - Zhiliang Yu
- College of Biotechnology and Bioengineering, Zhejiang University of Technology, Hangzhou, Zhejiang Province, China
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RdmA Is a Key Regulator in Autoinduction of DSF Quorum Quenching in Pseudomonas nitroreducens HS-18. mBio 2023; 14:e0301022. [PMID: 36537811 PMCID: PMC9973270 DOI: 10.1128/mbio.03010-22] [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] [Indexed: 12/24/2022] Open
Abstract
Diffusible signal factor (DSF) represents a family of widely conserved quorum-sensing (QS) signals which regulate virulence factor production and pathogenicity in numerous Gram-negative bacterial pathogens. We recently reported the identification of a highly potent DSF-quenching bacterial isolate, Pseudomonas nitroreducens HS-18, which contains an operon with four DSF-inducible genes, digABCD, or digA-D, that are responsible for degradation of DSF signals. However, the regulatory mechanisms that govern the digA-D response to DSF induction have not yet been characterized. In this study, we identified a novel transcriptional regulator we designated RdmA (regulator of DSF metabolism) which negatively regulates the expression of digA-D and represses DSF degradation. In addition, we found that a gene cluster located adjacent to rdmA was also negatively regulated by RdmA and played a key role in DSF degradation; this cluster was hence named dmg (DSF metabolism genes). An electrophoretic mobility shift assay and genetic analysis showed that RdmA represses the transcriptional expression of the dmg genes in a direct manner. Further studies demonstrated that DSF acts as an antagonist and binds to RdmA, which abrogates RdmA binding to the target promoter and its suppression on transcriptional expression of the dmg genes. Taken together, the results from this study have unveiled a central regulator and a gene cluster associated with the autoinduction of DSF degradation in P. nitroreducens HS-18, and this will aid in the understanding of the genetic basis and regulatory mechanisms that govern the quorum-quenching activity of this potent biocontrol agent. IMPORTANCE DSF family quorum-sensing (QS) signals play important roles in regulation of bacterial physiology and virulence in a wide range of plant and human bacterial pathogens. Quorum quenching (QQ), which acts by either degrading QS signals or blocking QS communication, has proven to be a potent disease control strategy, but QQ mechanisms that target DSF family signals and associated regulatory mechanisms remain largely unknown. Recently, we identified four autoinduced DSF degradation genes (digABCD) in P. nitroreducens HS-18. By using a combination of transcriptome and genetic analysis, we identified a central regulator that plays a key role in autoinduction of dig expression, as well as a new gene cluster (dmgABCDEFGH) involved in DSF degradation. The significance of our study is in unveiling the autoinduction mechanism that governs DSF signal quorum quenching for the first time, to our knowledge, and in identification of new genes and enzymes responsible for DSF degradation. The findings from this study shed new light on our understanding of the DSF metabolism pathway and the regulatory mechanisms that modulate DSF quorum quenching and will provide useful clues for design and development of a new generation of highly potent QQ biocontrol agents against DSF-mediated bacterial infections.
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Takeuchi T, Kameyama K, Miyauchi E, Nakanishi Y, Kanaya T, Fujii T, Kato T, Sasaki T, Tachibana N, Negishi H, Matsui M, Ohno H. Fatty acid overproduction by gut commensal microbiota exacerbates obesity. Cell Metab 2023; 35:361-375.e9. [PMID: 36652945 DOI: 10.1016/j.cmet.2022.12.013] [Citation(s) in RCA: 46] [Impact Index Per Article: 46.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/14/2020] [Revised: 07/25/2022] [Accepted: 12/19/2022] [Indexed: 01/19/2023]
Abstract
Although recent studies have highlighted the impact of gut microbes on the progression of obesity and its comorbidities, it is not fully understood how these microbes promote these disorders, especially in terms of the role of microbial metabolites. Here, we report that Fusimonas intestini, a commensal species of the family Lachnospiraceae, is highly colonized in both humans and mice with obesity and hyperglycemia, produces long-chain fatty acids such as elaidate, and consequently facilitates diet-induced obesity. High fat intake altered the expression of microbial genes involved in lipid production, such as the fatty acid metabolism regulator fadR. Monocolonization with a FadR-overexpressing Escherichia coli exacerbated the metabolic phenotypes, suggesting that the change in bacterial lipid metabolism is causally involved in disease progression. Mechanistically, the microbe-derived fatty acids impaired intestinal epithelial integrity to promote metabolic endotoxemia. Our study thus provides a mechanistic linkage between gut commensals and obesity through the overproduction of microbe-derived lipids.
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Affiliation(s)
- Tadashi Takeuchi
- Laboratory for Intestinal Ecosystem, RIKEN Center for Integrative Medical Sciences, Yokohama 230-0045, Japan
| | - Keishi Kameyama
- Institute of Food Sciences and Technologies, Ajinomoto Co., Inc., Kawasaki 210-8681, Japan
| | - Eiji Miyauchi
- Laboratory for Intestinal Ecosystem, RIKEN Center for Integrative Medical Sciences, Yokohama 230-0045, Japan; Institute for Molecular and Cellular Regulation, Gunma University, Maebashi 371-8512, Japan
| | - Yumiko Nakanishi
- Laboratory for Intestinal Ecosystem, RIKEN Center for Integrative Medical Sciences, Yokohama 230-0045, Japan
| | - Takashi Kanaya
- Laboratory for Intestinal Ecosystem, RIKEN Center for Integrative Medical Sciences, Yokohama 230-0045, Japan; Graduate School of Medical Life Science, Yokohama City University, Yokohama 230-0045, Japan
| | - Takayoshi Fujii
- Institute of Food Sciences and Technologies, Ajinomoto Co., Inc., Kawasaki 210-8681, Japan
| | - Tamotsu Kato
- Laboratory for Intestinal Ecosystem, RIKEN Center for Integrative Medical Sciences, Yokohama 230-0045, Japan
| | - Takaharu Sasaki
- Laboratory for Intestinal Ecosystem, RIKEN Center for Integrative Medical Sciences, Yokohama 230-0045, Japan
| | - Naoko Tachibana
- Laboratory for Intestinal Ecosystem, RIKEN Center for Integrative Medical Sciences, Yokohama 230-0045, Japan
| | - Hiroki Negishi
- Laboratory for Intestinal Ecosystem, RIKEN Center for Integrative Medical Sciences, Yokohama 230-0045, Japan; Graduate School of Medical Life Science, Yokohama City University, Yokohama 230-0045, Japan
| | - Misato Matsui
- Laboratory for Intestinal Ecosystem, RIKEN Center for Integrative Medical Sciences, Yokohama 230-0045, Japan; Graduate School of Medical Life Science, Yokohama City University, Yokohama 230-0045, Japan
| | - Hiroshi Ohno
- Laboratory for Intestinal Ecosystem, RIKEN Center for Integrative Medical Sciences, Yokohama 230-0045, Japan; Graduate School of Medical Life Science, Yokohama City University, Yokohama 230-0045, Japan.
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Degradation of Exogenous Fatty Acids in Escherichia coli. Biomolecules 2022; 12:biom12081019. [PMID: 35892328 PMCID: PMC9329746 DOI: 10.3390/biom12081019] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2022] [Revised: 07/19/2022] [Accepted: 07/19/2022] [Indexed: 12/10/2022] Open
Abstract
Many bacteria possess all the machineries required to grow on fatty acids (FA) as a unique source of carbon and energy. FA degradation proceeds through the β-oxidation cycle that produces acetyl-CoA and reduced NADH and FADH cofactors. In addition to all the enzymes required for β-oxidation, FA degradation also depends on sophisticated systems for its genetic regulation and for FA transport. The fact that these machineries are conserved in bacteria suggests a crucial role in environmental conditions, especially for enterobacteria. Bacteria also possess specific enzymes required for the degradation of FAs from their environment, again showing the importance of this metabolism for bacterial adaptation. In this review, we mainly describe FA degradation in the Escherichia coli model, and along the way, we highlight and discuss important aspects of this metabolism that are still unclear. We do not detail exhaustively the diversity of the machineries found in other bacteria, but we mention them if they bring additional information or enlightenment on specific aspects.
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11
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Sawant N, Singh H, Appukuttan D. Overview of the Cellular Stress Responses Involved in Fatty Acid Overproduction in E. coli. Mol Biotechnol 2021; 64:373-387. [PMID: 34796451 DOI: 10.1007/s12033-021-00426-4] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2021] [Accepted: 11/10/2021] [Indexed: 12/29/2022]
Abstract
Research on microbial fatty acid metabolism started in the late 1960s, and till date, various developments have aided in elucidating the fatty acid metabolism in great depth. Over the years, synthesis of microbial fatty acid has drawn industrial attention due to its diverse applications. However, fatty acid overproduction imparts various stresses on its metabolic pathways causing a bottleneck to further increase the fatty acid yields. Numerous strategies to increase fatty acid titres in Escherichia coli by pathway modulation have already been published, but the stress generated during fatty acid overproduction is relatively less studied. Stresses like pH, osmolarity and oxidative stress, not only lower fatty acid titres, but also alter the cell membrane composition, protein expression and membrane fluidity. This review discusses an overview of fatty acid synthesis pathway and presents a panoramic view of various stresses caused due to fatty acid overproduction in E. coli. It also addresses how certain stresses like high temperature and nitrogen limitation can boost fatty acid production. This review paper also highlights the interconnections that exist between these stresses.
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Affiliation(s)
- Neha Sawant
- Department of Biological Sciences, Sunandan Divatia School of Science, NMIMS Deemed to be University, Vile Parle (West), Mumbai, 400056, India
| | - Harinder Singh
- Department of Biological Sciences, Sunandan Divatia School of Science, NMIMS Deemed to be University, Vile Parle (West), Mumbai, 400056, India.
| | - Deepti Appukuttan
- Biosystems Engineering Lab, Department of Chemical Engineering, IIT Bombay, Powai, Mumbai, 400076, India.
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12
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The Classical, Yet Controversial, First Enzyme of Lipid Synthesis: Escherichia coli Acetyl-CoA Carboxylase. Microbiol Mol Biol Rev 2021; 85:e0003221. [PMID: 34132100 DOI: 10.1128/mmbr.00032-21] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Escherichia coli acetyl-CoA carboxylase (ACC), the enzyme responsible for synthesis of malonyl-CoA, the building block of fatty acid synthesis, is the paradigm bacterial ACC. Many reports on the structures and stoichiometry of the four subunits comprising the active enzyme as well as on regulation of ACC activity and expression have appeared in the almost 20 years since this subject was last reviewed. This review seeks to update and expand on these reports.
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13
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Hughes L, Roberts W, Johnson D. The impact of DNA adenine methyltransferase knockout on the development of triclosan resistance and antibiotic cross-resistance in Escherichia coli. Access Microbiol 2021; 3:acmi000178. [PMID: 33997609 PMCID: PMC8115981 DOI: 10.1099/acmi.0.000178] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2020] [Accepted: 10/27/2020] [Indexed: 11/18/2022] Open
Abstract
Background DNA adenine methyltransferase (dam) has been well documented for its role in regulation of replication, mismatch repair and transposition. Recent studies have also suggested a role for dam in protection against antibiotic stress, although this is not yet fully defined. We therefore evaluated the role of dam in the development of antibiotic resistance and triclosan-associated cross-resistance. Results A significant impact on growth rate was seen in the dam knockout compared to the parental strain. Known triclosan resistance-associated mutations in fabI were seen regardless of dam status, with an additional mutation in lrhA seen in the dam knockout. The expression of multiple antibiotic resistance-associated genes was significantly different between the parent and dam knockout post-resistance induction. Reversion rate assays showed that resistance mechanisms were stable. Conclusions dam knockout had a significant effect on growth, but its role in the development of antibiotic resistance is likely confined to those antibiotics using acrAD-containing efflux pumps.
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Affiliation(s)
- Lewis Hughes
- Biomedical Sciences, Leeds Beckett University, Leeds, UK
| | - Wayne Roberts
- Biomedical Sciences, Leeds Beckett University, Leeds, UK
| | - Donna Johnson
- Biomedical Sciences, Leeds Beckett University, Leeds, UK
- *Correspondence: Donna Johnson,
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14
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Cronan JE. The Escherichia coli FadR transcription factor: Too much of a good thing? Mol Microbiol 2020; 115:1080-1085. [PMID: 33283913 DOI: 10.1111/mmi.14663] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2020] [Revised: 11/29/2020] [Accepted: 12/01/2020] [Indexed: 12/19/2022]
Abstract
Escherichia coli FadR is a transcription factor regulated by acyl-CoA thioester binding that optimizes fatty acid (FA) metabolism in response to environmental FAs. FadR represses the fad genes of FA degradation (β-oxidation) and activates the fab genes of FA synthesis thereby allowing E. coli to have its cake (acyl chains for phospholipid synthesis) and eat it (degrade acyl chains to acetyl-CoA). Acyl-CoA binding of FadR derepresses the transcription of the fad genes and cancels fab gene transcriptional activation. Activation of fab genes was thought restricted to the fabA and fabB genes of unsaturated FA synthesis, but FadR overproduction markedly increases yields of all FA acyl chains. Subsequently, almost all of the remaining fab genes were shown to be transcriptionally activated by FadR binding, but binding was very weak. Why are the low-affinity sites retained? What effects on cell physiology would result from their conversion to high-affinity sites (thereby mimicking FadR overproduction)? Investigations of E. coli cell size determinants showed that FA synthesis primarily determines E. coli cell size. Upon modest induction of FadR, cell size increases, but at the cost of growth rate and accumulation of intracellular membranes. Greater induction resulted in further growth rate decreases and abnormal cells. Hence, too much FadR is bad. FadR is extraordinarily conserved in γ-proteobacteria but has migrated. Mycobacterium tuberculosis encodes FadR orthologs one of which is functional in E. coli. Strikingly, the FadR theme of acyl-CoA-dependent transcriptional regulation is found in a different transcription factor family where two Bacillus species plus bacterial and archaeal thermophiles contain related proteins of similar function.
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Affiliation(s)
- John E Cronan
- Departments of Microbiology and Biochemistry, University of Illinois, Urbana, IL, USA
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15
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Qin X, Dong R, He S, Zhou X, Zhang Z, Cui Y, Shi C, Liu Y, Shi X. Characterization of the role of ybgC in lysozyme resistance of Salmonella Enteritidis. Food Control 2020. [DOI: 10.1016/j.foodcont.2019.106732] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
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16
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Zhao L, Lu Y, Yang J, Fang Y, Zhu L, Ding Z, Wang C, Ma W, Hu X, Wang X. Expression regulation of multiple key genes to improve L-threonine in Escherichia coli. Microb Cell Fact 2020; 19:46. [PMID: 32093713 PMCID: PMC7041290 DOI: 10.1186/s12934-020-01312-5] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2019] [Accepted: 02/18/2020] [Indexed: 11/28/2022] Open
Abstract
Background Escherichia coli is an important strain for l-threonine production. Genetic switch is a ubiquitous regulatory tool for gene expression in prokaryotic cells. To sense and regulate intracellular or extracellular chemicals, bacteria evolve a variety of transcription factors. The key enzymes required for l-threonine biosynthesis in E. coli are encoded by the thr operon. The thr operon could coordinate expression of these genes when l-threonine is in short supply in the cell. Results The thrL leader regulatory elements were applied to regulate the expression of genes iclR, arcA, cpxR, gadE, fadR and pykF, while the threonine-activating promoters PcysH, PcysJ and PcysD were applied to regulate the expression of gene aspC, resulting in the increase of l-threonine production in an l-threonine producing E. coli strain TWF001. Firstly, different parts of the regulator thrL were inserted in the iclR regulator region in TWF001, and the best resulting strain TWF063 produced 16.34 g l-threonine from 40 g glucose after 30 h cultivation. Secondly, the gene aspC following different threonine-activating promoters was inserted into the chromosome of TWF063, and the best resulting strain TWF066 produced 17.56 g l-threonine from 40 g glucose after 30 h cultivation. Thirdly, the effect of expression regulation of arcA, cpxR, gadE, pykF and fadR was individually investigated on l-threonine production in TWF001. Finally, using TWF066 as the starting strain, the expression of genes arcA, cpxR, gadE, pykF and fadR was regulated individually or in combination to obtain the best strain for l-threonine production. The resulting strain TWF083, in which the expression of seven genes (iclR, aspC, arcA, cpxR, gadE, pykF, fadR and aspC) was regulated, produced 18.76 g l-threonine from 30 g glucose, 26.50 g l-threonine from 40 g glucose, or 26.93 g l-threonine from 50 g glucose after 30 h cultivation. In 48 h fed-batch fermentation, TWF083 could produce 116.62 g/L l‐threonine with a yield of 0.486 g/g glucose and productivity of 2.43 g/L/h. Conclusion The genetic engineering through the expression regulation of key genes is a better strategy than simple deletion of these genes to improve l-threonine production in E. coli. This strategy has little effect on the intracellular metabolism in the early stage of the growth but could increase l-threonine biosynthesis in the late stage.
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Affiliation(s)
- Lei Zhao
- State Key Laboratory of Food Science and Technology, Jiangnan University, 1800 Lihu Avenue, Wuxi, 214122, China.,International Joint Laboratory on Food Safety, Jiangnan University, Wuxi, 214122, China
| | - Ying Lu
- Nanjing Customs District P. R. China, Wuxi, 214122, China
| | - Jun Yang
- State Key Laboratory of Food Science and Technology, Jiangnan University, 1800 Lihu Avenue, Wuxi, 214122, China.,International Joint Laboratory on Food Safety, Jiangnan University, Wuxi, 214122, China
| | - Yu Fang
- State Key Laboratory of Food Science and Technology, Jiangnan University, 1800 Lihu Avenue, Wuxi, 214122, China.,International Joint Laboratory on Food Safety, Jiangnan University, Wuxi, 214122, China
| | - Lifei Zhu
- State Key Laboratory of Food Science and Technology, Jiangnan University, 1800 Lihu Avenue, Wuxi, 214122, China.,International Joint Laboratory on Food Safety, Jiangnan University, Wuxi, 214122, China
| | - Zhixiang Ding
- State Key Laboratory of Food Science and Technology, Jiangnan University, 1800 Lihu Avenue, Wuxi, 214122, China.,International Joint Laboratory on Food Safety, Jiangnan University, Wuxi, 214122, China
| | - Chenhui Wang
- State Key Laboratory of Food Science and Technology, Jiangnan University, 1800 Lihu Avenue, Wuxi, 214122, China.,International Joint Laboratory on Food Safety, Jiangnan University, Wuxi, 214122, China
| | - Wenjian Ma
- State Key Laboratory of Food Science and Technology, Jiangnan University, 1800 Lihu Avenue, Wuxi, 214122, China.,International Joint Laboratory on Food Safety, Jiangnan University, Wuxi, 214122, China
| | - Xiaoqing Hu
- State Key Laboratory of Food Science and Technology, Jiangnan University, 1800 Lihu Avenue, Wuxi, 214122, China.,International Joint Laboratory on Food Safety, Jiangnan University, Wuxi, 214122, China
| | - Xiaoyuan Wang
- State Key Laboratory of Food Science and Technology, Jiangnan University, 1800 Lihu Avenue, Wuxi, 214122, China. .,International Joint Laboratory on Food Safety, Jiangnan University, Wuxi, 214122, China. .,Key Laboratory of Industrial Biotechnology, Ministry of Education, School of Biotechnology, Jiangnan University, Wuxi, 214122, China.
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17
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Sun Y, Meng Q, Zhang Y, Gao H. Derepression of bkd by the FadR loss dictates elevated production of BCFAs and isoleucine starvation. Biochim Biophys Acta Mol Cell Biol Lipids 2019; 1865:158577. [PMID: 31759173 DOI: 10.1016/j.bbalip.2019.158577] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2019] [Accepted: 11/13/2019] [Indexed: 12/21/2022]
Abstract
In many γ-proteobacteria, FadR is recognized as a global transcriptional regulator: in addition to being the most prominent regulator for FA biosynthesis and degradation, the protein also mediates expression of many genes in diverse biological processes. In Shewanella oneidensis, a bacterium renowned for its respiratory versatility, FadR directly controls only a few genes. However, the FadR loss substantially increases BCFA contents and impairs growth. In this study, we showed that FadR is required to activate a number of important FA biosynthesis genes, including fabA, fabB, and fabH1. Although most of these genes are controlled by FadR in a direct manner, they are not critically responsible for the phenotypes resulting from the FadR depletion. Subsequent investigations identified BKD encoded by the bkd operon as the critical factor for enhanced BCFA production. In the absence of FadR, the bkd operon is derepressed, resulting in elevated conversion of 3MOP to 3-methylbutanoyl-CoA, one of the direct substrates for BCFA synthesis. We further showed that the growth defect of the fadR mutant is due to BCAA shortage, a scenario also attributable to excessive BKD: 3MOP, the common substrate for both BCFA and BCAA, is disproportionately used for BCFA synthesis, leading to reduced production of BCAA. Collectively, our findings reveal that the S. oneidensis FadR regulon is surely larger than previously proposed and a new mechanism by which FadR impacts bacterial physiology.
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Affiliation(s)
- Yijuan Sun
- Institute of Microbiology College of Life Sciences, Zhejiang University, Hangzhou, Zhejiang 310058, China
| | - Qiu Meng
- Institute of Microbiology College of Life Sciences, Zhejiang University, Hangzhou, Zhejiang 310058, China; College of Biotechnology and Bioengineering, Zhejiang University of Technology, 18 Chaowang Rd, Hangzhou, 310014, Zhejiang, China
| | - Yongting Zhang
- Institute of Microbiology College of Life Sciences, Zhejiang University, Hangzhou, Zhejiang 310058, China
| | - Haichun Gao
- Institute of Microbiology College of Life Sciences, Zhejiang University, Hangzhou, Zhejiang 310058, China.
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18
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Yang J, Fang Y, Wang J, Wang C, Zhao L, Wang X. Deletion of regulator-encoding genes fadR, fabR and iclR to increase L-threonine production in Escherichia coli. Appl Microbiol Biotechnol 2019; 103:4549-4564. [DOI: 10.1007/s00253-019-09818-8] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2019] [Revised: 03/19/2019] [Accepted: 03/31/2019] [Indexed: 12/25/2022]
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19
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Trinquier A, Ulmer JE, Gilet L, Figaro S, Hammann P, Kuhn L, Braun F, Condon C. tRNA Maturation Defects Lead to Inhibition of rRNA Processing via Synthesis of pppGpp. Mol Cell 2019; 74:1227-1238.e3. [PMID: 31003868 DOI: 10.1016/j.molcel.2019.03.030] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2019] [Revised: 03/07/2019] [Accepted: 03/24/2019] [Indexed: 02/03/2023]
Abstract
rRNAs and tRNAs universally require processing from longer primary transcripts to become functional for translation. Here, we describe an unsuspected link between tRNA maturation and the 3' processing of 16S rRNA, a key step in preparing the small ribosomal subunit for interaction with the Shine-Dalgarno sequence in prokaryotic translation initiation. We show that an accumulation of either 5' or 3' immature tRNAs triggers RelA-dependent production of the stringent response alarmone (p)ppGpp in the Gram-positive model organism Bacillus subtilis. The accumulation of (p)ppGpp and accompanying decrease in GTP levels specifically inhibit 16S rRNA 3' maturation. We suggest that cells can exploit this mechanism to sense potential slowdowns in tRNA maturation and adjust rRNA processing accordingly to maintain the appropriate functional balance between these two major components of the translation apparatus.
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MESH Headings
- Bacillus subtilis/genetics
- Bacillus subtilis/metabolism
- Base Sequence
- Gene Expression Regulation, Bacterial
- Guanosine Pentaphosphate/biosynthesis
- Guanosine Pentaphosphate/genetics
- Guanosine Triphosphate/metabolism
- Ligases/genetics
- Ligases/metabolism
- Nucleic Acid Conformation
- Peptide Chain Initiation, Translational
- RNA, Ribosomal, 16S/chemistry
- RNA, Ribosomal, 16S/genetics
- RNA, Ribosomal, 16S/metabolism
- RNA, Transfer/chemistry
- RNA, Transfer/genetics
- RNA, Transfer/metabolism
- Ribosome Subunits, Large, Bacterial/genetics
- Ribosome Subunits, Large, Bacterial/metabolism
- Ribosome Subunits, Small, Bacterial/genetics
- Ribosome Subunits, Small, Bacterial/metabolism
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Affiliation(s)
- Aude Trinquier
- UMR8261 (CNRS-Université Paris Diderot), Institut de Biologie Physico-Chimique, 13 rue Pierre et Marie Curie, 75005 Paris, France
| | - Jonathan E Ulmer
- UMR8261 (CNRS-Université Paris Diderot), Institut de Biologie Physico-Chimique, 13 rue Pierre et Marie Curie, 75005 Paris, France
| | - Laetitia Gilet
- UMR8261 (CNRS-Université Paris Diderot), Institut de Biologie Physico-Chimique, 13 rue Pierre et Marie Curie, 75005 Paris, France
| | - Sabine Figaro
- UMR8261 (CNRS-Université Paris Diderot), Institut de Biologie Physico-Chimique, 13 rue Pierre et Marie Curie, 75005 Paris, France
| | - Philippe Hammann
- Plateforme Proteomique Strasbourg - Esplanade, Institut de Biologie Moléculaire et Cellulaire, CNRS FR1589, 15 rue Descartes, 67084 Strasbourg Cedex, France
| | - Lauriane Kuhn
- Plateforme Proteomique Strasbourg - Esplanade, Institut de Biologie Moléculaire et Cellulaire, CNRS FR1589, 15 rue Descartes, 67084 Strasbourg Cedex, France
| | - Frédérique Braun
- UMR8261 (CNRS-Université Paris Diderot), Institut de Biologie Physico-Chimique, 13 rue Pierre et Marie Curie, 75005 Paris, France.
| | - Ciarán Condon
- UMR8261 (CNRS-Université Paris Diderot), Institut de Biologie Physico-Chimique, 13 rue Pierre et Marie Curie, 75005 Paris, France.
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20
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Wang K, Sybers D, Maklad HR, Lemmens L, Lewyllie C, Zhou X, Schult F, Bräsen C, Siebers B, Valegård K, Lindås AC, Peeters E. A TetR-family transcription factor regulates fatty acid metabolism in the archaeal model organism Sulfolobus acidocaldarius. Nat Commun 2019; 10:1542. [PMID: 30948713 PMCID: PMC6449355 DOI: 10.1038/s41467-019-09479-1] [Citation(s) in RCA: 35] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2018] [Accepted: 03/12/2019] [Indexed: 01/18/2023] Open
Abstract
Fatty acid metabolism and its regulation are known to play important roles in bacteria and eukaryotes. By contrast, although certain archaea appear to metabolize fatty acids, the regulation of the underlying pathways in these organisms remains unclear. Here, we show that a TetR-family transcriptional regulator (FadRSa) is involved in regulation of fatty acid metabolism in the crenarchaeon Sulfolobus acidocaldarius. Functional and structural analyses show that FadRSa binds to DNA at semi-palindromic recognition sites in two distinct stoichiometric binding modes depending on the operator sequence. Genome-wide transcriptomic and chromatin immunoprecipitation analyses demonstrate that the protein binds to only four genomic sites, acting as a repressor of a 30-kb gene cluster comprising 23 open reading frames encoding lipases and β-oxidation enzymes. Fatty acyl-CoA molecules cause dissociation of FadRSa binding by inducing conformational changes in the protein. Our results indicate that, despite its similarity in overall structure to bacterial TetR-family FadR regulators, FadRSa displays a different acyl-CoA binding mode and a distinct regulatory mechanism. Certain archaea appear to metabolize fatty acids, but the regulation of these pathways is unclear. Here, Wang et al. provide genetic, functional and structural evidence supporting that a TetR-family transcriptional regulator is involved in regulation of fatty acid metabolism in Sulfolobus acidocaldarius.
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Affiliation(s)
- Kun Wang
- Department of Molecular Biosciences, The Wenner-Gren Institute, Stockholm University, Svante Arrhenius v. 20C, SE-10691, Stockholm, Sweden
| | - David Sybers
- Research Group of Microbiology, Department of Bioengineering Sciences, Vrije Universiteit Brussel, Pleinlaan 2, B-1050, Brussels, Belgium
| | - Hassan Ramadan Maklad
- Research Group of Microbiology, Department of Bioengineering Sciences, Vrije Universiteit Brussel, Pleinlaan 2, B-1050, Brussels, Belgium
| | - Liesbeth Lemmens
- Research Group of Microbiology, Department of Bioengineering Sciences, Vrije Universiteit Brussel, Pleinlaan 2, B-1050, Brussels, Belgium
| | - Charlotte Lewyllie
- Research Group of Microbiology, Department of Bioengineering Sciences, Vrije Universiteit Brussel, Pleinlaan 2, B-1050, Brussels, Belgium.,Laboratory of Cell Genetics, Department of Biology, Vrije Universiteit Brussel, Pleinlaan 2, B-1050, Brussels, Belgium
| | - Xiaoxiao Zhou
- Molekulare Enzymtechnologie und Biochemie, Biofilm Centre, ZWU, Fakultät für Chemie, Universität Duisburg-Essen, Universitätsstr. 2, 45117, Essen, Germany
| | - Frank Schult
- Molekulare Enzymtechnologie und Biochemie, Biofilm Centre, ZWU, Fakultät für Chemie, Universität Duisburg-Essen, Universitätsstr. 2, 45117, Essen, Germany
| | - Christopher Bräsen
- Molekulare Enzymtechnologie und Biochemie, Biofilm Centre, ZWU, Fakultät für Chemie, Universität Duisburg-Essen, Universitätsstr. 2, 45117, Essen, Germany
| | - Bettina Siebers
- Molekulare Enzymtechnologie und Biochemie, Biofilm Centre, ZWU, Fakultät für Chemie, Universität Duisburg-Essen, Universitätsstr. 2, 45117, Essen, Germany
| | - Karin Valegård
- Molecular Biophysics, Department of Cell and Molecular Biology, Uppsala University, Uppsala, Sweden
| | - Ann-Christin Lindås
- Department of Molecular Biosciences, The Wenner-Gren Institute, Stockholm University, Svante Arrhenius v. 20C, SE-10691, Stockholm, Sweden.
| | - Eveline Peeters
- Research Group of Microbiology, Department of Bioengineering Sciences, Vrije Universiteit Brussel, Pleinlaan 2, B-1050, Brussels, Belgium.
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21
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Microbial Production of Fatty Acid via Metabolic Engineering and Synthetic Biology. BIOTECHNOL BIOPROC E 2019. [DOI: 10.1007/s12257-018-0374-6] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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22
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Thomanek N, Arends J, Lindemann C, Barkovits K, Meyer HE, Marcus K, Narberhaus F. Intricate Crosstalk Between Lipopolysaccharide, Phospholipid and Fatty Acid Metabolism in Escherichia coli Modulates Proteolysis of LpxC. Front Microbiol 2019; 9:3285. [PMID: 30692974 PMCID: PMC6339880 DOI: 10.3389/fmicb.2018.03285] [Citation(s) in RCA: 29] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2018] [Accepted: 12/17/2018] [Indexed: 12/26/2022] Open
Abstract
Lipopolysaccharides (LPS) in the outer membrane of Gram-negative bacteria provide the first line of defense against antibiotics and other harmful compounds. LPS biosynthesis critically depends on LpxC catalyzing the first committed enzyme in this process. In Escherichia coli, the cellular concentration of LpxC is adjusted in a growth rate-dependent manner by the FtsH protease making sure that LPS biosynthesis is coordinated with the cellular demand. As a result, LpxC is stable in fast-growing cells and prone to degradation in slow-growing cells. One of the factors involved in this process is the alarmone guanosine tetraphosphate (ppGpp) but previous studies suggested the involvement of yet unknown factors in LpxC degradation. We established a quantitative proteomics approach aiming at the identification of proteins that are associated with LpxC and/or FtsH at high or low growth rates. The identification of known LpxC and FtsH interactors validated our approach. A number of proteins involved in fatty acid biosynthesis and degradation, including the central regulator FadR, were found in the LpxC and/or FtsH interactomes. Another protein associated with LpxC and FtsH was WaaH, a LPS-modifying enzyme. When overproduced, several members of the LpxC/FtsH interactomes were able to modulate LpxC proteolysis. Our results go beyond the previously established link between LPS and phospholipid biosynthesis and uncover a far-reaching network that controls LPS production by involving multiple enzymes in fatty acid metabolism, phospholipid biosynthesis and LPS modification.
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Affiliation(s)
- Nikolas Thomanek
- Medical Proteome Center, Ruhr University Bochum, Bochum, Germany
| | - Jan Arends
- Microbial Biology, Ruhr University Bochum, Bochum, Germany
| | | | | | - Helmut E Meyer
- Medical Proteome Center, Ruhr University Bochum, Bochum, Germany.,Biomedical Research, Leibniz-Institut für Analytische Wissenschaften - ISAS - e. V., Dortmund, Germany
| | - Katrin Marcus
- Medical Proteome Center, Ruhr University Bochum, Bochum, Germany
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23
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Barbey C, Chane A, Burini JF, Maillot O, Merieau A, Gallique M, Beury-Cirou A, Konto-Ghiorghi Y, Feuilloley M, Gobert V, Latour X. A Rhodococcal Transcriptional Regulatory Mechanism Detects the Common Lactone Ring of AHL Quorum-Sensing Signals and Triggers the Quorum-Quenching Response. Front Microbiol 2018; 9:2800. [PMID: 30524404 PMCID: PMC6262395 DOI: 10.3389/fmicb.2018.02800] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2018] [Accepted: 10/31/2018] [Indexed: 01/08/2023] Open
Abstract
The biocontrol agent Rhodococcus erythropolis disrupts virulence of plant and human Gram-negative pathogens by catabolizing their N-acyl-homoserine lactones. This quorum-quenching activity requires the expression of the qsd (quorum-sensing signal degradation) operon, which encodes the lactonase QsdA and the fatty acyl-CoA ligase QsdC, involved in the catabolism of lactone ring and acyl chain moieties of signaling molecules, respectively. Here, we demonstrate the regulation of qsd operon expression by a TetR-like family repressor, QsdR. This repression was lifted by adding the pathogen quorum signal or by deleting the qsdR gene, resulting in enhanced lactone degrading activity. Using interactomic approaches and transcriptional fusion strategy, the qsd operon derepression was elucidated: it is operated by the binding of the common part of signaling molecules, the homoserine lactone ring, to the effector-receiving domain of QsdR, preventing a physical binding of QsdR to the qsd promoter region. To our knowledge, this is the first evidence revealing quorum signals as inducers of the suitable quorum-quenching pathway, confirming this TetR-like protein as a lactone sensor. This regulatory mechanism designates the qsd operon as encoding a global disrupting pathway for degrading a wide range of signal substrates, allowing a broad spectrum anti-virulence activity mediated by the rhodococcal biocontrol agent. Understanding the regulation mechanisms of qsd operon expression led also to the development of biosensors useful to monitor in situ the presence of exogenous signals and quorum-quenching activity.
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Affiliation(s)
- Corinne Barbey
- Laboratoire de Microbiologie Signaux et Microenvironnement (LMSM EA 4312) - Normandie Université - LMSM, Évreux, France.,Structure Fédérative de Recherche Normandie Végétal 4277 (NORVEGE), Mont-Saint-Aignan, France.,Seeds Innovation Protection Research and Environment, Achicourt, France.,Seeds Innovation Protection Research and Environment, Bretteville du Grand-Caux, France
| | - Andrea Chane
- Laboratoire de Microbiologie Signaux et Microenvironnement (LMSM EA 4312) - Normandie Université - LMSM, Évreux, France.,Structure Fédérative de Recherche Normandie Végétal 4277 (NORVEGE), Mont-Saint-Aignan, France
| | - Jean-François Burini
- Laboratoire de Microbiologie Signaux et Microenvironnement (LMSM EA 4312) - Normandie Université - LMSM, Évreux, France.,Structure Fédérative de Recherche Normandie Végétal 4277 (NORVEGE), Mont-Saint-Aignan, France
| | - Olivier Maillot
- Laboratoire de Microbiologie Signaux et Microenvironnement (LMSM EA 4312) - Normandie Université - LMSM, Évreux, France.,Structure Fédérative de Recherche Normandie Végétal 4277 (NORVEGE), Mont-Saint-Aignan, France
| | - Annabelle Merieau
- Laboratoire de Microbiologie Signaux et Microenvironnement (LMSM EA 4312) - Normandie Université - LMSM, Évreux, France.,Structure Fédérative de Recherche Normandie Végétal 4277 (NORVEGE), Mont-Saint-Aignan, France
| | - Mathias Gallique
- Laboratoire de Microbiologie Signaux et Microenvironnement (LMSM EA 4312) - Normandie Université - LMSM, Évreux, France.,Structure Fédérative de Recherche Normandie Végétal 4277 (NORVEGE), Mont-Saint-Aignan, France
| | - Amélie Beury-Cirou
- Seeds Innovation Protection Research and Environment, Achicourt, France.,Seeds Innovation Protection Research and Environment, Bretteville du Grand-Caux, France.,French Federation of Seed Potato Growers (FN3PT/RD3PT), Paris, France
| | - Yoan Konto-Ghiorghi
- Laboratoire de Microbiologie Signaux et Microenvironnement (LMSM EA 4312) - Normandie Université - LMSM, Évreux, France.,Structure Fédérative de Recherche Normandie Végétal 4277 (NORVEGE), Mont-Saint-Aignan, France
| | - Marc Feuilloley
- Laboratoire de Microbiologie Signaux et Microenvironnement (LMSM EA 4312) - Normandie Université - LMSM, Évreux, France.,Structure Fédérative de Recherche Normandie Végétal 4277 (NORVEGE), Mont-Saint-Aignan, France
| | - Virginie Gobert
- Seeds Innovation Protection Research and Environment, Achicourt, France.,Seeds Innovation Protection Research and Environment, Bretteville du Grand-Caux, France.,French Federation of Seed Potato Growers (FN3PT/RD3PT), Paris, France
| | - Xavier Latour
- Laboratoire de Microbiologie Signaux et Microenvironnement (LMSM EA 4312) - Normandie Université - LMSM, Évreux, France.,Structure Fédérative de Recherche Normandie Végétal 4277 (NORVEGE), Mont-Saint-Aignan, France
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24
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Effect of amino acids on transcription and translation of key genes in E. coli K and B grown at a steady state in minimal medium. N Biotechnol 2018; 49:120-128. [PMID: 30385399 DOI: 10.1016/j.nbt.2018.10.004] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2018] [Revised: 10/24/2018] [Accepted: 10/26/2018] [Indexed: 02/01/2023]
Abstract
Growing E. coli to high densities is a common strategy for biologicals production. The process is implemented by using complex or minimal media with different feeding strategies. To understand the effect of amino acids, E. coli B and K were grown at a steady state of 0.35 h-1 in glucose minimal medium with and without amino acids, while their metabolism, protein abundance and gene expression were compared. The results showed that amino acids promoted higher acetate excretion, higher fatty acid biosynthesis (K strain), repressed glucose uptake rate, and decreased expression of proteins associated with the TCA cycle, glyoxylate shunt and amino acid biosynthesis. In presence of amino acids, E. coli K upregulated fatty acid biosynthesis and repressed more genes and proteins involved in amino acid biosynthesis than E. coli B. These findings are correlated with higher yield on glucose (Yx/s) and high specific biomass production rate (qx) in K strain in the presence of amino acids. In contrast, pre-formed precursor molecules such as amino acids did not affect fatty acid biosynthesis in E. coli B or Yx/s and qx, which were higher than those of E. coli K, suggesting that constitutive synthesis of energetically demanding precursors and higher fatty acid β-oxidation activity is key for high biomass-performer E. coli B. Both strains turned off unnecessary pathways and directed their metabolism to proteome efficient overflow metabolism likely to generate energy and provide protein to functions supporting higher growth rate.
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25
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Siroli L, Braschi G, de Jong A, Kok J, Patrignani F, Lanciotti R. Transcriptomic approach and membrane fatty acid analysis to study the response mechanisms of Escherichia coli to thyme essential oil, carvacrol, 2-(E)-hexanal and citral exposure. J Appl Microbiol 2018; 125:1308-1320. [PMID: 30028070 DOI: 10.1111/jam.14048] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2018] [Revised: 06/21/2018] [Accepted: 07/15/2018] [Indexed: 12/18/2022]
Abstract
AIMS The application of essential oils (EOs) and their components as food preservatives is promising but requires a deeper understanding of their mechanisms of action. This study aims to evaluate the effects of thyme EO, carvacrol, citral and 2-(E)-hexenal, on whole-genome gene expression (the transcriptome), as well as the fatty acid (FA) composition of the cell membranes of Escherichia coli K12. METHODS AND RESULTS Therefore, we studied the response against 1 h of exposure to sublethal concentrations of natural antimicrobials, of exponentially growing E. coli K12, using DNA microarray technology and a gas chromatographic method. The results show that treatment with a sublethal concentration of the antimicrobials strongly affects global gene expression in E. coli for all antimicrobials used. Major changes in the expression of genes involved in metabolic pathways as well as in FA biosynthesis and protection against oxidative stress were evidenced. Moreover, the sublethal treatments resulted in increased levels of unsaturated and cyclic FAs as well as an increase in the chain length compared to the controls. CONCLUSIONS The down-regulation of genes involved in aerobic metabolism indicates a shift from respiration to fermentative growth. Moreover, the results obtained suggest that the cytoplasmic membrane of E. coli is the major cellular target of EOs and their components. In addition, the key role of membrane unsaturated FAs in the response mechanisms of E. coli to natural antimicrobials has been confirmed in this study. SIGNIFICANCE AND IMPACT OF THE STUDY The transcriptomic data obtained signify a further step to understand the mechanisms of action of natural antimicrobials also when sublethal concentrations and short-term exposure. In addition, this research goes in deep correlating the transcriptomic modification with the changes in E. coli FA composition of cell membrane identified as the main target of the natural antimicrobials.
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Affiliation(s)
- L Siroli
- Department of Agricultural and Food Sciences, Alma Mater Studiorum, University of Bologna, Campus of Food Science, Cesena, Italy.,Interdipartimental Centre for Industrial Research-CIRI-AGRIFOOD, Alma Mater Studiorum, University of Bologna, Cesena (FC), Italy
| | - G Braschi
- Department of Agricultural and Food Sciences, Alma Mater Studiorum, University of Bologna, Campus of Food Science, Cesena, Italy
| | - A de Jong
- Department of Molecular Genetics, Groningen Biomolecular Sciences and Biotechnology Institute, University of Groningen, AG Groningen, The Netherlands
| | - J Kok
- Department of Molecular Genetics, Groningen Biomolecular Sciences and Biotechnology Institute, University of Groningen, AG Groningen, The Netherlands
| | - F Patrignani
- Department of Agricultural and Food Sciences, Alma Mater Studiorum, University of Bologna, Campus of Food Science, Cesena, Italy.,Interdipartimental Centre for Industrial Research-CIRI-AGRIFOOD, Alma Mater Studiorum, University of Bologna, Cesena (FC), Italy
| | - R Lanciotti
- Department of Agricultural and Food Sciences, Alma Mater Studiorum, University of Bologna, Campus of Food Science, Cesena, Italy.,Interdipartimental Centre for Industrial Research-CIRI-AGRIFOOD, Alma Mater Studiorum, University of Bologna, Cesena (FC), Italy
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26
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Salas-Navarrete C, Hernández-Chávez G, Flores N, Martínez LM, Martinez A, Bolívar F, Barona-Gomez F, Gosset G. Increasing pinosylvin production in Escherichia coli by reducing the expression level of the gene fabI -encoded enoyl-acyl carrier protein reductase. ELECTRON J BIOTECHN 2018. [DOI: 10.1016/j.ejbt.2018.03.001] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
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27
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Kim J, Yoo HW, Kim M, Kim EJ, Sung C, Lee PG, Park BG, Kim BG. Rewiring FadR regulon for the selective production of ω-hydroxy palmitic acid from glucose in Escherichia coli. Metab Eng 2018; 47:414-422. [PMID: 29719215 DOI: 10.1016/j.ymben.2018.04.021] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2018] [Revised: 04/19/2018] [Accepted: 04/28/2018] [Indexed: 12/28/2022]
Abstract
ω-Hydroxy palmitic acid (ω-HPA) is a valuable compound for an ingredient of artificially synthesized ceramides and an additive for lubricants and adhesives. Production of such a fatty acid derivative is limited by chemical catalysis, but plausible by biocatalysis. However, its low productivity issue, including formations of unsaturated fatty acid (UFA) byproducts in host cells, remains as a hurdle toward industrial biological processes. In this study, to achieve selective and high-level production of ω-HPA from glucose in Escherichia coli, FadR, a native transcriptional regulator of fatty acid metabolism, and its regulon were engineered. First, FadR was co-expressed with a thioesterase with a specificity toward palmitic acid production to enhance palmitic acid production yield, but a considerable quantity of UFAs was also produced. In order to avoid the UFA production caused by fadR overexpression, FadR regulon was rewired by i) mutating FadR consensus binding sites of fabA or fabB, ii) integrating fabZ into fabI operon, and iii) enhancing the strength of fabI promoter. This approach led to dramatic increases in both proportion (48.3-83.0%) and titer (377.8 mg/L to 675.8 mg/L) of palmitic acid, mainly due to the decrease in UFA synthesis. Introducing a fatty acid ω-hydroxylase, CYP153A35, into the engineered strain resulted in a highly selective production of ω-HPA (83.5 mg/L) accounting for 87.5% of total ω-hydroxy fatty acids. Furthermore, strategies, such as i) enhancement in CYP153A35 activity, ii) expression of a fatty acid transporter, iii) supplementation of triton X-100, and iv) separation of the ω-HPA synthetic pathway into two strains for a co-culture system, were applied and resulted in 401.0 mg/L of ω-HPA production. For such selective productions of palmitic acid and ω-HPA, the rewiring of FadR regulation in E. coli is a promising strategy to develop an industrial process with economical downstream processing.
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Affiliation(s)
- Joonwon Kim
- School of Chemical and Biological Engineering, Seoul National University, 1, Gwanak-ro, Gwanak-gu, Seoul 08826, Republic of Korea; Institute of Molecular Biology and Genetics, Seoul National University, Seoul 08826, Republic of Korea
| | - Hee-Wang Yoo
- Institute of Molecular Biology and Genetics, Seoul National University, Seoul 08826, Republic of Korea; Interdisciplinary Program of Bioengineering, Seoul National University, Seoul 08826, Republic of Korea
| | - Minsuk Kim
- Institute of Engineering Research, Seoul National University, Seoul 08826, Republic of Korea
| | - Eun-Jung Kim
- Institute of Molecular Biology and Genetics, Seoul National University, Seoul 08826, Republic of Korea; Bio-MAX Institute, Seoul National University, Seoul 08826, Republic of Korea
| | - Changmin Sung
- Doping Control Center, Korea Institute of Science and Technology, Seoul 02792, Republic of Korea
| | - Pyung-Gang Lee
- School of Chemical and Biological Engineering, Seoul National University, 1, Gwanak-ro, Gwanak-gu, Seoul 08826, Republic of Korea; Institute of Molecular Biology and Genetics, Seoul National University, Seoul 08826, Republic of Korea
| | - Beom Gi Park
- School of Chemical and Biological Engineering, Seoul National University, 1, Gwanak-ro, Gwanak-gu, Seoul 08826, Republic of Korea; Institute of Molecular Biology and Genetics, Seoul National University, Seoul 08826, Republic of Korea
| | - Byung-Gee Kim
- School of Chemical and Biological Engineering, Seoul National University, 1, Gwanak-ro, Gwanak-gu, Seoul 08826, Republic of Korea; Institute of Molecular Biology and Genetics, Seoul National University, Seoul 08826, Republic of Korea; Interdisciplinary Program of Bioengineering, Seoul National University, Seoul 08826, Republic of Korea; Institute of Engineering Research, Seoul National University, Seoul 08826, Republic of Korea.
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28
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Mustoe AM, Busan S, Rice GM, Hajdin CE, Peterson BK, Ruda VM, Kubica N, Nutiu R, Baryza JL, Weeks KM. Pervasive Regulatory Functions of mRNA Structure Revealed by High-Resolution SHAPE Probing. Cell 2018; 173:181-195.e18. [PMID: 29551268 DOI: 10.1016/j.cell.2018.02.034] [Citation(s) in RCA: 175] [Impact Index Per Article: 29.2] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2017] [Revised: 01/02/2018] [Accepted: 02/15/2018] [Indexed: 11/25/2022]
Abstract
mRNAs can fold into complex structures that regulate gene expression. Resolving such structures de novo has remained challenging and has limited our understanding of the prevalence and functions of mRNA structure. We use SHAPE-MaP experiments in living E. coli cells to derive quantitative, nucleotide-resolution structure models for 194 endogenous transcripts encompassing approximately 400 genes. Individual mRNAs have exceptionally diverse architectures, and most contain well-defined structures. Active translation destabilizes mRNA structure in cells. Nevertheless, mRNA structure remains similar between in-cell and cell-free environments, indicating broad potential for structure-mediated gene regulation. We find that the translation efficiency of endogenous genes is regulated by unfolding kinetics of structures overlapping the ribosome binding site. We discover conserved structured elements in 35% of UTRs, several of which we validate as novel protein binding motifs. RNA structure regulates every gene studied here in a meaningful way, implying that most functional structures remain to be discovered.
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Affiliation(s)
- Anthony M Mustoe
- Department of Chemistry, University of North Carolina, Chapel Hill, NC, USA.
| | - Steven Busan
- Department of Chemistry, University of North Carolina, Chapel Hill, NC, USA
| | - Greggory M Rice
- Department of Chemistry, University of North Carolina, Chapel Hill, NC, USA; Novartis Institutes for Biomedical Research, Inc., Cambridge, MA, USA
| | | | - Brant K Peterson
- Novartis Institutes for Biomedical Research, Inc., Cambridge, MA, USA
| | - Vera M Ruda
- Novartis Institutes for Biomedical Research, Inc., Cambridge, MA, USA
| | - Neil Kubica
- Novartis Institutes for Biomedical Research, Inc., Cambridge, MA, USA
| | - Razvan Nutiu
- Novartis Institutes for Biomedical Research, Inc., Cambridge, MA, USA
| | - Jeremy L Baryza
- Novartis Institutes for Biomedical Research, Inc., Cambridge, MA, USA
| | - Kevin M Weeks
- Department of Chemistry, University of North Carolina, Chapel Hill, NC, USA.
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29
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Xu L, Wang L, Zhou XR, Chen WC, Singh S, Hu Z, Huang FH, Wan X. Stepwise metabolic engineering of Escherichia coli to produce triacylglycerol rich in medium-chain fatty acids. BIOTECHNOLOGY FOR BIOFUELS 2018; 11:177. [PMID: 29983740 PMCID: PMC6016142 DOI: 10.1186/s13068-018-1177-x] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/17/2018] [Accepted: 06/18/2018] [Indexed: 05/08/2023]
Abstract
BACKGROUND Triacylglycerols (TAGs) rich in medium-chain fatty acids (MCFAs, C10-14 fatty acids) are valuable feedstocks for biofuels and chemicals. Natural sources of TAGs rich in MCFAs are restricted to a limited number of plant species, which are unsuitable for mass agronomic production. Instead, the modification of seed or non-seed tissue oils to increase MCFA content has been investigated. In addition, microbial oils are considered as promising sustainable feedstocks for providing TAGs, although little has been done to tailor the fatty acids in microbial TAGs. RESULTS Here, we first assessed various wax synthase/acyl-coenzyme A:diacylglycerol acyltransferases, phosphatidic acid phosphatases, acyl-CoA synthetases as well as putative fatty acid metabolism regulators for producing high levels of TAGs in Escherichia coli. Activation of endogenous free fatty acids with tailored chain length via overexpression of the castor thioesterase RcFatB and the subsequent incorporation of such fatty acids into glycerol backbones shifted the TAG profile in the desired way. Metabolic and nutrient optimization of the engineered bacterial cells resulted in greatly elevated TAG levels (399.4 mg/L) with 43.8% MCFAs, representing the highest TAG levels in E. coli under shake flask conditions. Engineered cells were observed to contain membrane-bound yet robust lipid droplets. CONCLUSIONS We introduced a complete Kennedy pathway into non-oleaginous E. coli towards developing a bacterial platform for the sustainable production of TAGs rich in MCFAs. Strategies reported here illustrate the possibility of prokaryotic cell factories for the efficient production of TAGs rich in MCFAs.
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Affiliation(s)
- Lin Xu
- Oil Crops Research Institute of the Chinese Academy of Agricultural Sciences, Wuhan, 430062 People’s Republic of China
| | - Lian Wang
- Oil Crops Research Institute of the Chinese Academy of Agricultural Sciences, Wuhan, 430062 People’s Republic of China
| | | | - Wen-Chao Chen
- Oil Crops Research Institute of the Chinese Academy of Agricultural Sciences, Wuhan, 430062 People’s Republic of China
- Key Laboratory of Biology and Genetic Improvement of Oil Crops, Ministry of Agriculture, Wuhan, 430062 People’s Republic of China
- Oil Crops and Lipids Process Technology National & Local Joint Engineering Laboratory, Wuhan, 430062 People’s Republic of China
- Hubei Key Laboratory of Lipid Chemistry and Nutrition, Wuhan, 430062 People’s Republic of China
| | | | - Zhe Hu
- State Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, Wuhan, 430070 People’s Republic of China
| | - Feng-Hong Huang
- Oil Crops Research Institute of the Chinese Academy of Agricultural Sciences, Wuhan, 430062 People’s Republic of China
- Key Laboratory of Biology and Genetic Improvement of Oil Crops, Ministry of Agriculture, Wuhan, 430062 People’s Republic of China
- Oil Crops and Lipids Process Technology National & Local Joint Engineering Laboratory, Wuhan, 430062 People’s Republic of China
- Hubei Key Laboratory of Lipid Chemistry and Nutrition, Wuhan, 430062 People’s Republic of China
| | - Xia Wan
- Oil Crops Research Institute of the Chinese Academy of Agricultural Sciences, Wuhan, 430062 People’s Republic of China
- Key Laboratory of Biology and Genetic Improvement of Oil Crops, Ministry of Agriculture, Wuhan, 430062 People’s Republic of China
- Oil Crops and Lipids Process Technology National & Local Joint Engineering Laboratory, Wuhan, 430062 People’s Republic of China
- Hubei Key Laboratory of Lipid Chemistry and Nutrition, Wuhan, 430062 People’s Republic of China
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30
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Kizawa A, Kawahara A, Takashima K, Takimura Y, Nishiyama Y, Hihara Y. The LexA transcription factor regulates fatty acid biosynthetic genes in the cyanobacterium Synechocystis sp. PCC 6803. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2017; 92:189-198. [PMID: 28744961 DOI: 10.1111/tpj.13644] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/07/2016] [Revised: 06/22/2017] [Accepted: 07/18/2017] [Indexed: 05/12/2023]
Abstract
Specific transcription factors have been identified in various heterotrophic bacterial species that regulate the sets of genes required for fatty acid metabolism. Here, we report that expression of the fab genes, encoding fatty acid biosynthetic enzymes, is regulated by the global regulator LexA in the photoautotrophic cyanobacterium Synechocystis sp. PCC 6803. Sll1626, an ortholog of the well-known LexA repressor involved in the SOS response in heterotrophic bacteria, was isolated from crude extracts of Synechocystis by DNA affinity chromatography, reflecting its binding to the upstream region of the acpP-fabF and fabI genes. An electrophoresis mobility shift assay revealed that the recombinant LexA protein can bind to the upstream region of each fab gene tested (fabD, fabH, fabF, fabG, fabZ and fabI). Quantitative RT-PCR analysis of the wild type and a lexA-disrupted mutant strain suggested that LexA acts as a repressor of the fab genes involved in initiation of fatty acid biosynthesis (fabD, fabH and fabF) and the first reductive step in the subsequent elongation cycle (fabG) under normal growth conditions. Under nitrogen-depleted conditions, downregulation of fab gene expression is partly achieved through an increase in LexA-repressing activity. In contrast, under phosphate-depleted conditions, fab gene expression is upregulated, probably due to the loss of repression by LexA. We further demonstrate that elimination of LexA largely increases the production of fatty acids in strains modified to secrete free fatty acids.
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Affiliation(s)
- Ayumi Kizawa
- Graduate School of Science and Engineering, Saitama University, Saitama, 338-8570, Japan
| | - Akihito Kawahara
- Biological Science Research, KAO Corporation, Wakayama, 640-8580, Japan
| | - Kosuke Takashima
- Graduate School of Science and Engineering, Saitama University, Saitama, 338-8570, Japan
| | - Yasushi Takimura
- Biological Science Research, KAO Corporation, Wakayama, 640-8580, Japan
| | - Yoshitaka Nishiyama
- Graduate School of Science and Engineering, Saitama University, Saitama, 338-8570, Japan
| | - Yukako Hihara
- Graduate School of Science and Engineering, Saitama University, Saitama, 338-8570, Japan
- Core Research of Evolutional Science and Technology (CREST), Japan Science and Technology Agency (JST), Saitama, 332-0012, Japan
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31
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Kim Y, Chhor G, Tsai CS, Fox G, Chen CS, Winans NJ, Jedrzejczak R, Joachimiak A, Winans SC. X-ray crystal structures of the pheromone-binding domains of two quorum-hindered transcription factors, YenR of Yersinia enterocolitica and CepR2 of Burkholderia cenocepacia. Proteins 2017; 85:1831-1844. [PMID: 28614901 PMCID: PMC7001585 DOI: 10.1002/prot.25336] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2017] [Revised: 06/08/2017] [Accepted: 06/12/2017] [Indexed: 12/17/2022]
Abstract
The ability of LuxR-type proteins to regulate transcription is controlled by bacterial pheromones, N-acylhomoserine lactones (AHLs). Most LuxR-family proteins require their cognate AHLs for activity, and some of them require AHLs for folding and stability, and for protease-resistance. However, a few members of this family are able to fold, dimerize, bind DNA, and regulate transcription in the absence of AHLs; moreover, these proteins are antagonized by their cognate AHLs. One such protein is YenR of Yersinia enterocolitica, which is antagonized by N-3-oxohexanoyl-l-homoserine lactone (OHHL). This pheromone is produced by the OHHL synthase, a product of the adjacent yenI gene. Another example is CepR2 of Burkholderia cenocepacia, which is antagonized by N-octanoyl-l-homoserine lactone (OHL), whose synthesis is directed by the cepI gene of the same bacterium. Here, we describe the high-resolution crystal structures of the AHL binding domains of YenR and CepR2. YenR was crystallized in the presence and absence of OHHL. While this ligand does not cause large scale changes in the YenR structure, it does alter the orientation of several highly conserved YenR residues within and near the pheromone-binding pocket, which in turn caused a significant movement of a surface-exposed loop.
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Affiliation(s)
- Youngchang Kim
- Midwest Center for Structural Genomics, Biosciences, Argonne National Laboratory, Argonne, Illinois 60439
- Structural Biology Center, Biosciences, Argonne National Laboratory, Argonne, Illinois 60439
| | - Gekleng Chhor
- Midwest Center for Structural Genomics, Biosciences, Argonne National Laboratory, Argonne, Illinois 60439
| | - Ching-Sung Tsai
- Department of Microbiology, Cornell University, Ithaca, New York 14853
| | - Gabriel Fox
- Department of Microbiology, Cornell University, Ithaca, New York 14853
| | - Chia-Sui Chen
- Department of Microbiology, Cornell University, Ithaca, New York 14853
| | - Nathan J. Winans
- Department of Microbiology, Cornell University, Ithaca, New York 14853
| | - Robert Jedrzejczak
- Structural Biology Center, Biosciences, Argonne National Laboratory, Argonne, Illinois 60439
| | - Andrzej Joachimiak
- Midwest Center for Structural Genomics, Biosciences, Argonne National Laboratory, Argonne, Illinois 60439
- Structural Biology Center, Biosciences, Argonne National Laboratory, Argonne, Illinois 60439
- Department of Biochemistry and Molecular Biology, University of Chicago, Chicago, Illinois 60637
| | - Stephen C. Winans
- Department of Microbiology, Cornell University, Ithaca, New York 14853
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The Fatty Acid Regulator FadR Influences the Expression of the Virulence Cascade in the El Tor Biotype of Vibrio cholerae by Modulating the Levels of ToxT via Two Different Mechanisms. J Bacteriol 2017; 199:JB.00762-16. [PMID: 28115548 DOI: 10.1128/jb.00762-16] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2016] [Accepted: 01/17/2017] [Indexed: 01/16/2023] Open
Abstract
FadR is a master regulator of fatty acid (FA) metabolism that coordinates the pathways of FA degradation and biosynthesis in enteric bacteria. We show here that a ΔfadR mutation in the El Tor biotype of Vibrio cholerae prevents the expression of the virulence cascade by influencing both the transcription and the posttranslational regulation of the master virulence regulator ToxT. FadR is a transcriptional regulator that represses the expression of genes involved in FA degradation, activates the expression of genes involved in unsaturated FA (UFA) biosynthesis, and also activates the expression of two operons involved in saturated FA (SFA) biosynthesis. Since FadR does not bind directly to the toxT promoter, we determined whether the regulation of any of its target genes indirectly influenced ToxT. This was accomplished by individually inserting a double point mutation into the FadR-binding site in the promoter of each target gene, thereby preventing their activation or repression. Although preventing FadR-mediated activation of fabA, which encodes the enzyme that carries out the first step in UFA biosynthesis, did not significantly influence either the transcription or the translation of ToxT, it reduced its levels and prevented virulence gene expression. In the mutant strain unable to carry out FadR-mediated activation of fabA, expressing fabA ectopically restored the levels of ToxT and virulence gene expression. Taken together, the results presented here indicate that V. cholerae FadR influences the virulence cascade in the El Tor biotype by modulating the levels of ToxT via two different mechanisms.IMPORTANCE Fatty acids (FAs) play important roles in membrane lipid homeostasis and energy metabolism in all organisms. In Vibrio cholerae, the causative agent of the acute intestinal disease cholera, they also influence virulence by binding into an N-terminal pocket of the master virulence regulator, ToxT, and modulating its activity. FadR is a transcription factor that coordinately controls the pathways of FA degradation and biosynthesis in enteric bacteria. This study identifies a new link between FA metabolism and virulence in the El Tor biotype by showing that FadR influences both the transcription and posttranslational regulation of the master virulence regulator ToxT by two distinct mechanisms.
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33
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Crozier L, Hedley PE, Morris J, Wagstaff C, Andrews SC, Toth I, Jackson RW, Holden NJ. Whole-Transcriptome Analysis of Verocytotoxigenic Escherichia coli O157:H7 (Sakai) Suggests Plant-Species-Specific Metabolic Responses on Exposure to Spinach and Lettuce Extracts. Front Microbiol 2016; 7:1088. [PMID: 27462311 PMCID: PMC4940412 DOI: 10.3389/fmicb.2016.01088] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2016] [Accepted: 06/29/2016] [Indexed: 12/11/2022] Open
Abstract
Verocytotoxigenic Escherichia coli (VTEC) can contaminate crop plants, potentially using them as secondary hosts, which can lead to food-borne infection. Currently, little is known about the influence of the specific plant species on the success of bacterial colonization. As such, we compared the ability of the VTEC strain, E. coli O157:H7 'Sakai,' to colonize the roots and leaves of four leafy vegetables: spinach (Spinacia oleracea), lettuce (Lactuca sativa), vining green pea (Pisum sativum), and prickly lettuce (Lactuca serriola), a wild relative of domesticated lettuce. Also, to determine the drivers of the initial response on interaction with plant tissue, the whole transcriptome of E. coli O157:H7 Sakai was analyzed following exposure to plant extracts of varying complexity (spinach leaf lysates or root exudates, and leaf cell wall polysaccharides from spinach or lettuce). Plant extracts were used to reduce heterogeneity inherent in plant-microbe interactions and remove the effect of plant immunity. This dual approach provided information on the initial adaptive response of E. coli O157:H7 Sakai to the plant environment together with the influence of the living plant during bacterial establishment and colonization. Results showed that both the plant tissue type and the plant species strongly influence the short-term (1 h) transcriptional response to extracts as well as longer-term (10 days) plant colonization or persistence. We show that propagation temperature (37 vs. 18°C) has a major impact on the expression profile and therefore pre-adaptation of bacteria to a plant-relevant temperature is necessary to avoid misleading temperature-dependent wholescale gene-expression changes in response to plant material. For each of the plant extracts tested, the largest group of (annotated) differentially regulated genes were associated with metabolism. However, large-scale differences in the metabolic and biosynthetic pathways between treatment types indicate specificity in substrate utilization. Induction of stress-response genes reflected the apparent physiological status of the bacterial genes in each extract, as a result of glutamate-dependent acid resistance, nutrient stress, or translational stalling. A large proportion of differentially regulated genes are uncharacterized (annotated as hypothetical), which could indicate yet to be described functional roles associated with plant interaction for E. coli O157:H7 Sakai.
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Affiliation(s)
- Louise Crozier
- Cell and Molecular Sciences, The James Hutton InstituteDundee, UK
| | - Pete E. Hedley
- Cell and Molecular Sciences, The James Hutton InstituteDundee, UK
| | - Jenny Morris
- Cell and Molecular Sciences, The James Hutton InstituteDundee, UK
| | - Carol Wagstaff
- School of Chemistry, Food and Pharmacy, The University of ReadingReading, UK
| | - Simon C. Andrews
- School of Biological Sciences, The University of ReadingReading, UK
| | - Ian Toth
- Cell and Molecular Sciences, The James Hutton InstituteDundee, UK
| | | | - Nicola J. Holden
- Cell and Molecular Sciences, The James Hutton InstituteDundee, UK
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