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Jiao M, He W, Ouyang Z, Qin Q, Guo Y, Zhang J, Bai Y, Guo X, Yu Q, She J, Hwang PM, Zheng F, Wen Y. Mechanistic and structural insights into the bifunctional enzyme PaaY from Acinetobacter baumannii. Structure 2023; 31:935-947.e4. [PMID: 37329879 DOI: 10.1016/j.str.2023.05.015] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2022] [Revised: 03/28/2023] [Accepted: 05/23/2023] [Indexed: 06/19/2023]
Abstract
PaaY is a thioesterase that enables toxic metabolites to be degraded through the bacterial phenylacetic acid (PA) pathway. The Acinetobacter baumannii gene FQU82_01591 encodes PaaY, which we demonstrate to possess γ-carbonic anhydrase activity in addition to thioesterase activity. The crystal structure of AbPaaY in complex with bicarbonate reveals a homotrimer with a canonical γ-carbonic anhydrase active site. Thioesterase activity assays demonstrate a preference for lauroyl-CoA as a substrate. The AbPaaY trimer structure shows a unique domain-swapped C-termini, which increases the stability of the enzyme in vitro and decreases its susceptibility to proteolysis in vivo. The domain-swapped C-termini impact thioesterase substrate specificity and enzyme efficacy without affecting carbonic anhydrase activity. AbPaaY knockout reduced the growth of Acinetobacter in media containing PA, decreased biofilm formation, and impaired hydrogen peroxide resistance. Collectively, AbPaaY is a bifunctional enzyme that plays a key role in the metabolism, growth, and stress response mechanisms of A. baumannii.
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Affiliation(s)
- Min Jiao
- Center for Microbiome Research of Med-X Institute, Shaanxi Provincial Key Laboratory of Sepsis in Critical Care Medicine, The First Affiliated Hospital, Xi'an Jiaotong University, Xi'an 710061, China
| | - Wenbo He
- Center for Microbiome Research of Med-X Institute, Shaanxi Provincial Key Laboratory of Sepsis in Critical Care Medicine, The First Affiliated Hospital, Xi'an Jiaotong University, Xi'an 710061, China
| | - Zhenlin Ouyang
- Center for Microbiome Research of Med-X Institute, Shaanxi Provincial Key Laboratory of Sepsis in Critical Care Medicine, The First Affiliated Hospital, Xi'an Jiaotong University, Xi'an 710061, China
| | - Qian Qin
- Center for Microbiome Research of Med-X Institute, Shaanxi Provincial Key Laboratory of Sepsis in Critical Care Medicine, The First Affiliated Hospital, Xi'an Jiaotong University, Xi'an 710061, China
| | - Yucheng Guo
- The Key Laboratory of Environment and Genes Related to Disease of Ministry of Education Health Science Center, Xi'an Jiaotong University, Xi'an 710061, China
| | - Jiaxin Zhang
- The Key Laboratory of Environment and Genes Related to Disease of Ministry of Education Health Science Center, Xi'an Jiaotong University, Xi'an 710061, China
| | - Yixin Bai
- Center for Microbiome Research of Med-X Institute, Shaanxi Provincial Key Laboratory of Sepsis in Critical Care Medicine, The First Affiliated Hospital, Xi'an Jiaotong University, Xi'an 710061, China
| | - Xiaolong Guo
- Center for Microbiome Research of Med-X Institute, Shaanxi Provincial Key Laboratory of Sepsis in Critical Care Medicine, The First Affiliated Hospital, Xi'an Jiaotong University, Xi'an 710061, China
| | - Qinyue Yu
- Center for Microbiome Research of Med-X Institute, Shaanxi Provincial Key Laboratory of Sepsis in Critical Care Medicine, The First Affiliated Hospital, Xi'an Jiaotong University, Xi'an 710061, China
| | - Junjun She
- Center for Microbiome Research of Med-X Institute, Shaanxi Provincial Key Laboratory of Sepsis in Critical Care Medicine, The First Affiliated Hospital, Xi'an Jiaotong University, Xi'an 710061, China
| | - Peter M Hwang
- Departments of Medicine and Biochemistry, Faculty of Medicine & Dentistry, University of Alberta, Edmonton, AB T6G 2R3, Canada
| | - Fang Zheng
- The Key Laboratory of Environment and Genes Related to Disease of Ministry of Education Health Science Center, Xi'an Jiaotong University, Xi'an 710061, China
| | - Yurong Wen
- Center for Microbiome Research of Med-X Institute, Shaanxi Provincial Key Laboratory of Sepsis in Critical Care Medicine, The First Affiliated Hospital, Xi'an Jiaotong University, Xi'an 710061, China; The Key Laboratory of Environment and Genes Related to Disease of Ministry of Education Health Science Center, Xi'an Jiaotong University, Xi'an 710061, China.
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Junghare M, Frey J, Naji KM, Spiteller D, Vaaje-Kolstad G, Schink B. Isophthalate:coenzyme A ligase initiates anaerobic degradation of xenobiotic isophthalate. BMC Microbiol 2022; 22:227. [PMID: 36171563 PMCID: PMC9516798 DOI: 10.1186/s12866-022-02630-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2022] [Accepted: 09/02/2022] [Indexed: 11/25/2022] Open
Abstract
Background Environmental contamination from synthetic plastics and their additives is a widespread problem. Phthalate esters are a class of refractory synthetic organic compounds which are widely used in plastics, coatings, and for several industrial applications such as packaging, pharmaceuticals, and/or paints. They are released into the environment during production, use and disposal, and some of them are potential mutagens and carcinogens. Isophthalate (1,3-benzenedicarboxylic acid) is a synthetic chemical that is globally produced at a million-ton scale for industrial applications and is considered a priority pollutant. Here we describe the biochemical characterization of an enzyme involved in anaerobic degradation of isophthalate by the syntrophically fermenting bacterium Syntrophorhabdus aromaticivorans strain UI that activate isophthalate to isophthalyl-CoA followed by its decarboxylation to benzoyl-CoA. Results Isophthalate:Coenzyme A ligase (IPCL, AMP-forming) that activates isophthalate to isophthalyl-CoA was heterologously expressed in E. coli (49.6 kDa) for biochemical characterization. IPCL is homologous to phenylacetate-CoA ligase that belongs to the family of ligases that form carbon-sulfur bonds. In the presence of coenzyme A, Mg2+ and ATP, IPCL converts isophthalate to isophthalyl-CoA, AMP and pyrophosphate (PPi). The enzyme was specifically induced after anaerobic growth of S. aromaticivorans in a medium containing isophthalate as the sole carbon source. Therefore, IPCL exhibited high substrate specificity and affinity towards isophthalate. Only substrates that are structurally related to isophthalate, such as glutarate and 3-hydroxybenzoate, could be partially converted to the respective coenzyme A esters. Notably, no activity could be measured with substrates such as phthalate, terephthalate and benzoate. Acetyl-CoA or succinyl-CoA did not serve as CoA donors. The enzyme has a theoretical pI of 6.8 and exhibited optimal activity between pH 7.0 to 7.5. The optimal temperature was between 25 °C and 37 °C. Denaturation temperature (Tm) of IPCL was found to be at about 63 °C. The apparent KM values for isophthalate, CoA, and ATP were 409 μM, 642 μM, and 3580 μM, respectively. Although S. aromaticivorans is a strictly anaerobic bacterium, the enzyme was found to be oxygen-insensitive and catalysed isophthalyl-CoA formation under both anoxic and oxic conditions. Conclusion We have successfully cloned the ipcl gene, expressed and characterized the corresponding IPCL enzyme, which plays a key role in isophthalate activation that initiates its activation and further degradation by S. aromaticivorans. Its biochemical characterization represents an important step in the elucidation of the complete degradation pathway of isophthalate. Supplementary Information The online version contains supplementary material available at 10.1186/s12866-022-02630-x.
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Affiliation(s)
- Madan Junghare
- General Microbiology and Microbial Ecology, Department of Biology, University of Konstanz, D-78457, Constance, Germany. .,Faculty of Chemistry, Biotechnology and Food Science, Norwegian University of Life Sciences (NMBU), 1430, Ås, Norway.
| | - Jasmin Frey
- General Microbiology and Microbial Ecology, Department of Biology, University of Konstanz, D-78457, Constance, Germany
| | - Khalid M Naji
- Chemical Ecology and Biological Chemistry, Department of Biology, University of Konstanz, D-78457, Constance, Germany
| | - Dieter Spiteller
- Chemical Ecology and Biological Chemistry, Department of Biology, University of Konstanz, D-78457, Constance, Germany
| | - Gustav Vaaje-Kolstad
- Faculty of Chemistry, Biotechnology and Food Science, Norwegian University of Life Sciences (NMBU), 1430, Ås, Norway
| | - Bernhard Schink
- General Microbiology and Microbial Ecology, Department of Biology, University of Konstanz, D-78457, Constance, Germany
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3
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Jiao M, He W, Ouyang Z, Shi Q, Wen Y. Progress in structural and functional study of the bacterial phenylacetic acid catabolic pathway, its role in pathogenicity and antibiotic resistance. Front Microbiol 2022; 13:964019. [PMID: 36160191 PMCID: PMC9493321 DOI: 10.3389/fmicb.2022.964019] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2022] [Accepted: 08/08/2022] [Indexed: 11/13/2022] Open
Abstract
Phenylacetic acid (PAA) is a central intermediate metabolite involved in bacterial degradation of aromatic components. The bacterial PAA pathway mainly contains 12 enzymes and a transcriptional regulator, which are involved in biofilm formation and antimicrobial activity. They are present in approximately 16% of the sequenced bacterial genome. In this review, we have summarized the PAA distribution in microbes, recent structural and functional study progress of the enzyme families of the bacterial PAA pathway, and their role in bacterial pathogenicity and antibiotic resistance. The enzymes of the bacterial PAA pathway have shown potential as an antimicrobial drug target for biotechnological applications in metabolic engineering.
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Affiliation(s)
- Min Jiao
- Department of Critical Care Medicine, Center for Microbiome Research of Med-X Institute, The First Affiliated Hospital, Xi’an Jiaotong University, Xi’an, China
| | - Wenbo He
- Department of Critical Care Medicine, Center for Microbiome Research of Med-X Institute, The First Affiliated Hospital, Xi’an Jiaotong University, Xi’an, China
| | - Zhenlin Ouyang
- Department of Critical Care Medicine, Center for Microbiome Research of Med-X Institute, The First Affiliated Hospital, Xi’an Jiaotong University, Xi’an, China
| | - Qindong Shi
- Department of Critical Care Medicine, The First Affiliated Hospital, Xi’an Jiaotong University, Xi’an, China
| | - Yurong Wen
- Department of Critical Care Medicine, Center for Microbiome Research of Med-X Institute, The First Affiliated Hospital, Xi’an Jiaotong University, Xi’an, China
- Department of Critical Care Medicine, The First Affiliated Hospital, Xi’an Jiaotong University, Xi’an, China
- The Key Laboratory of Environment and Genes Related to Disease of Ministry of Education Health Science Center, Xi’an Jiaotong University, Xi’an, China
- *Correspondence: Yurong Wen,
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Abstract
Aryl coenzyme A (CoA) ligases belong to class I of the adenylate-forming enzyme superfamily (ANL superfamily). They catalyze the formation of thioester bonds between aromatic compounds and CoA and occur in nearly all forms of life. These ligases are involved in various metabolic pathways degrading benzene, toluene, ethylbenzene, and xylene (BTEX) or polycyclic aromatic hydrocarbons (PAHs). They are often necessary to produce the central intermediate benzoyl-CoA that occurs in various anaerobic pathways. The substrate specificity is very diverse between enzymes within the same class, while the dependency on Mg2+, ATP, and CoA as well as oxygen insensitivity are characteristics shared by the whole enzyme class. Some organisms employ the same aryl-CoA ligase when growing aerobically and anaerobically, while others induce different enzymes depending on the environmental conditions. Aryl-CoA ligases can be divided into two major groups, benzoate:CoA ligase-like enzymes and phenylacetate:CoA ligase-like enzymes. They are widely distributed between the phylogenetic clades of the ANL superfamily and show closer relationships within the subfamilies than to other aryl-CoA ligases. This, together with residual CoA ligase activity in various other enzymes of the ANL superfamily, leads to the conclusion that CoA ligases might be the ancestral proteins from which all other ANL superfamily enzymes developed.
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Duan Y, Toplak M, Hou A, Brock NL, Dickschat JS, Teufel R. A Flavoprotein Dioxygenase Steers Bacterial Tropone Biosynthesis via Coenzyme A-Ester Oxygenolysis and Ring Epoxidation. J Am Chem Soc 2021; 143:10413-10421. [PMID: 34196542 PMCID: PMC8283759 DOI: 10.1021/jacs.1c04996] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
![]()
Bacterial tropone
natural products such as tropolone, tropodithietic
acid, or the roseobacticides play crucial roles in various terrestrial
and marine symbiotic interactions as virulence factors, antibiotics,
algaecides, or quorum sensing signals. We now show that their poorly
understood biosynthesis depends on a shunt product from aerobic CoA-dependent
phenylacetic acid catabolism that is salvaged by the dedicated acyl-CoA
dehydrogenase-like flavoenzyme TdaE. Further characterization of TdaE
revealed an unanticipated complex catalysis, comprising substrate
dehydrogenation, noncanonical CoA-ester oxygenolysis, and final ring
epoxidation. The enzyme thereby functions as an archetypal flavoprotein
dioxygenase that incorporates both oxygen atoms from O2 into the substrate, most likely involving flavin-N5-peroxide and
flavin-N5-oxide species for consecutive CoA-ester cleavage and epoxidation,
respectively. The subsequent spontaneous decarboxylation of the reactive
enzyme product yields tropolone, which serves as a key virulence factor
in rice panicle blight caused by pathogenic edaphic Burkholderia
plantarii. Alternatively, the TdaE product is most likely
converted to more complex sulfur-containing secondary metabolites
such as tropodithietic acid from predominant marine Rhodobacteraceae (e.g., Phaeobacter inhibens).
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Affiliation(s)
- Ying Duan
- Faculty of Biology, University of Freiburg, Schänzlestrasse 1, 79104 Freiburg, Germany
| | - Marina Toplak
- Faculty of Biology, University of Freiburg, Schänzlestrasse 1, 79104 Freiburg, Germany
| | - Anwei Hou
- Kekulé-Institute of Organic Chemistry and Biochemistry, University of Bonn, Gerhard-Domagk-Strasse 1, 53121 Bonn, Germany
| | - Nelson L Brock
- Institute of Organic Chemistry, TU Braunschweig, Hagenring 30, 38106 Braunschweig, Germany
| | - Jeroen S Dickschat
- Kekulé-Institute of Organic Chemistry and Biochemistry, University of Bonn, Gerhard-Domagk-Strasse 1, 53121 Bonn, Germany.,Institute of Organic Chemistry, TU Braunschweig, Hagenring 30, 38106 Braunschweig, Germany
| | - Robin Teufel
- Faculty of Biology, University of Freiburg, Schänzlestrasse 1, 79104 Freiburg, Germany
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Duan Y, Petzold M, Saleem‐Batcha R, Teufel R. Bacterial Tropone Natural Products and Derivatives: Overview of their Biosynthesis, Bioactivities, Ecological Role and Biotechnological Potential. Chembiochem 2020; 21:2384-2407. [PMID: 32239689 PMCID: PMC7497051 DOI: 10.1002/cbic.201900786] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2019] [Revised: 04/02/2020] [Indexed: 12/05/2022]
Abstract
Tropone natural products are non-benzene aromatic compounds of significant ecological and pharmaceutical interest. Herein, we highlight current knowledge on bacterial tropones and their derivatives such as tropolones, tropodithietic acid, and roseobacticides. Their unusual biosynthesis depends on a universal CoA-bound precursor featuring a seven-membered carbon ring as backbone, which is generated by a side reaction of the phenylacetic acid catabolic pathway. Enzymes encoded by separate gene clusters then further modify this key intermediate by oxidation, CoA-release, or incorporation of sulfur among other reactions. Tropones play important roles in the terrestrial and marine environment where they act as antibiotics, algaecides, or quorum sensing signals, while their bacterial producers are often involved in symbiotic interactions with plants and marine invertebrates (e. g., algae, corals, sponges, or mollusks). Because of their potent bioactivities and of slowly developing bacterial resistance, tropones and their derivatives hold great promise for biomedical or biotechnological applications, for instance as antibiotics in (shell)fish aquaculture.
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Affiliation(s)
- Ying Duan
- Faculty of BiologyUniversity of Freiburg79104FreiburgGermany
| | - Melanie Petzold
- Faculty of BiologyUniversity of Freiburg79104FreiburgGermany
| | | | - Robin Teufel
- Faculty of BiologyUniversity of Freiburg79104FreiburgGermany
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Liu WW, Pan J, Feng X, Li M, Xu Y, Wang F, Zhou NY. Evidences of aromatic degradation dominantly via the phenylacetic acid pathway in marine benthic Thermoprofundales. Environ Microbiol 2019; 22:329-342. [PMID: 31691434 DOI: 10.1111/1462-2920.14850] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2019] [Revised: 10/26/2019] [Accepted: 11/03/2019] [Indexed: 01/09/2023]
Abstract
Thermoprofundales (Marine Benthic Group D archaea, MBG-D) is a newly proposed archaeal order and widely distributed in global marine sediment, and the members in the order may play a vital role in carbon cycling. However, the lack of pure cultures of these oeganisms has hampered the recognition of their catabolic roles. Here, by constructing high-quality metagenome-assembled genomes (MAGs) of two new subgroups of Thermoprofundales from hydrothermal sediment and predicting their catabolic pathways, we here provide genomic evidences that Thermoprofundales are capable of degrading aromatics via the phenylacetic acid (PAA) pathway. Then, the gene sequences of phenylacetyl-CoA ligase (PCL), a key enzyme for the PAA pathway, were searched in reference genomes. The widespread distribution of PCL genes among 14.9% of archaea and 75.9% of Thermoprofundales further supports the importance of the PAA pathway in archaea, particularly in Thermoprofundales where no ring-cleavage dioxygenases were found. Two PCLs from Thermoprofundales MAGs, PCLM8-3 and PCLM10-15 , were able to convert PAA to phenylacetyl-CoA (PA-CoA) in vitro, demonstrating the involvement of Thermoprofundales in aromatics degradation through PAA via CoA activation. Their acid tolerance (pH 5-7), high-optimum temperatures (60°C and 80°C), thermostability (stable at 60°C and 50°C for 48 h) and broad substrate spectra imply that Thermoprofundales are capable of transforming aromatics under extreme conditions. Together with the evidence of in situ transcriptional activities for most genes related to the aromatics pathway in Thermoprofundales, these genomic, and biochemical evidences highlight the essential role of this ubiquitous and abundant archaeal order in the carbon cycle of marine sediments.
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Affiliation(s)
- Wei-Wei Liu
- State Key Laboratory of Microbial Metabolism & School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai, 200240, China.,Joint International Research Laboratory of Metabolic & Developmental Sciences, Shanghai Jiao Tong University, Shanghai, 200240, China
| | - Jie Pan
- Institute for Advanced Study, Shenzhen University, Shenzhen, 518060, China
| | - Xiaoyuan Feng
- State Key Laboratory of Microbial Metabolism & School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai, 200240, China.,Joint International Research Laboratory of Metabolic & Developmental Sciences, Shanghai Jiao Tong University, Shanghai, 200240, China
| | - Meng Li
- Institute for Advanced Study, Shenzhen University, Shenzhen, 518060, China
| | - Ying Xu
- State Key Laboratory of Microbial Metabolism & School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai, 200240, China.,Joint International Research Laboratory of Metabolic & Developmental Sciences, Shanghai Jiao Tong University, Shanghai, 200240, China
| | - Fengping Wang
- State Key Laboratory of Microbial Metabolism & School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai, 200240, China.,Joint International Research Laboratory of Metabolic & Developmental Sciences, Shanghai Jiao Tong University, Shanghai, 200240, China
| | - Ning-Yi Zhou
- State Key Laboratory of Microbial Metabolism & School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai, 200240, China.,Joint International Research Laboratory of Metabolic & Developmental Sciences, Shanghai Jiao Tong University, Shanghai, 200240, China
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8
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Structures of 2-Hydroxyisobutyric Acid-CoA Ligase Reveal Determinants of Substrate Specificity and Describe a Multi-Conformational Catalytic Cycle. J Mol Biol 2019; 431:2747-2761. [DOI: 10.1016/j.jmb.2019.05.027] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2018] [Revised: 05/14/2019] [Accepted: 05/16/2019] [Indexed: 02/01/2023]
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9
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Junghare M, Spiteller D, Schink B. Anaerobic degradation of xenobiotic isophthalate by the fermenting bacterium Syntrophorhabdus aromaticivorans. ISME JOURNAL 2019; 13:1252-1268. [PMID: 30647456 DOI: 10.1038/s41396-019-0348-5] [Citation(s) in RCA: 32] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Subscribe] [Scholar Register] [Received: 08/03/2018] [Revised: 12/19/2018] [Accepted: 12/22/2018] [Indexed: 12/13/2022]
Abstract
Syntrophorhabdus aromaticivorans is a syntrophically fermenting bacterium that can degrade isophthalate (3-carboxybenzoate). It is a xenobiotic compound which has accumulated in the environment for more than 50 years due to its global industrial usage and can cause negative effects on the environment. Isophthalate degradation by the strictly anaerobic S. aromaticivorans was investigated to advance our understanding of the degradation of xenobiotics introduced into nature, and to identify enzymes that might have ecological significance for bioremediation. Differential proteome analysis of isophthalate- vs benzoate-grown cells revealed over 400 differentially expressed proteins of which only four were unique to isophthalate-grown cells. The isophthalate-induced proteins include a phenylacetate:CoA ligase, a UbiD-like decarboxylase, a UbiX-like flavin prenyltransferase, and a hypothetical protein. These proteins are encoded by genes forming a single gene cluster that putatively codes for anaerobic conversion of isophthalate to benzoyl-CoA. Subsequently, benzoyl-CoA is metabolized by the enzymes of the anaerobic benzoate degradation pathway that were identified in the proteomic analysis. In vitro enzyme assays with cell-free extracts of isophthalate-grown cells indicated that isophthalate is activated to isophthalyl-CoA by an ATP-dependent isophthalate:CoA ligase (IPCL), and subsequently decarboxylated to benzoyl-CoA by a UbiD family isophthalyl-CoA decarboxylase (IPCD) that requires a prenylated flavin mononucleotide (prFMN) cofactor supplied by UbiX to effect decarboxylation. Phylogenetic analysis revealed that IPCD is a novel member of the functionally diverse UbiD family (de)carboxylases. Homologs of the IPCD encoding genes are found in several other bacteria, such as aromatic compound-degrading denitrifiers, marine sulfate-reducers, and methanogenic communities in a terephthalate-degrading reactor. These results suggest that metabolic strategies adapted for degradation of isophthalate and other phthalate are conserved between microorganisms that are involved in the anaerobic degradation of environmentally relevant aromatic compounds.
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Affiliation(s)
- Madan Junghare
- Microbial Ecology, Department of Biology, University of Konstanz, 78457, Konstanz, Germany.
| | - Dieter Spiteller
- Chemical Ecology, Department of Biology, University of Konstanz, 78457, Konstanz, Germany
| | - Bernhard Schink
- Microbial Ecology, Department of Biology, University of Konstanz, 78457, Konstanz, Germany
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10
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Ye J, Zhu Y, Hou B, Wu H, Zhang H. Characterization of the bagremycin biosynthetic gene cluster in Streptomyces sp. Tü 4128. Biosci Biotechnol Biochem 2018; 83:482-489. [PMID: 30526412 DOI: 10.1080/09168451.2018.1553605] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
Bagremycin A and bagremycin B isolated from Streptomyces sp. Tü 4128 have activities against Gram-positive bacteria, fungi and also have a weak antitumor activity, which make them have great potential for development of novel antibiotics. Here, we report a draft genome 8,424,112 bp in length of S. sp. Tü 4128 by Illumina Hiseq2000, and identify the bagremycins biosynthetic gene cluster (BGC) by bioinformatics analysis. The putative bagremycins BGC includes 16 open reading frames (ORFs) with the functions of biosynthesis, resistance and regulation. Disruptions of relative genes and HPLC analysis of bagremycins production demonstrated that not all the genes within the BGC are responsible for the biosynthesis of bagremycins. In addition, the biosynthetic pathways of bagremycins are proposed for deeper inquiries into their intriguing biosynthetic mechanism.
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Affiliation(s)
- Jiang Ye
- a State Key Laboratory of Bioreactor Engineering , East China University of Science and Technology , Shanghai , China.,b Department of Applied Biology , East China University of Science and Technology , Shanghai , China
| | - Yunxia Zhu
- b Department of Applied Biology , East China University of Science and Technology , Shanghai , China
| | - Bingbing Hou
- a State Key Laboratory of Bioreactor Engineering , East China University of Science and Technology , Shanghai , China.,b Department of Applied Biology , East China University of Science and Technology , Shanghai , China
| | - Haizhen Wu
- a State Key Laboratory of Bioreactor Engineering , East China University of Science and Technology , Shanghai , China.,b Department of Applied Biology , East China University of Science and Technology , Shanghai , China
| | - Huizhan Zhang
- a State Key Laboratory of Bioreactor Engineering , East China University of Science and Technology , Shanghai , China.,b Department of Applied Biology , East China University of Science and Technology , Shanghai , China
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11
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Diverse metabolic pathways in the degradation of phenylalkanoic acids and their monohydroxylated derivatives in Cupriavidus sp. strain ST-14. Process Biochem 2018. [DOI: 10.1016/j.procbio.2018.08.031] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
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12
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Heine T, Zimmerling J, Ballmann A, Kleeberg SB, Rückert C, Busche T, Winkler A, Kalinowski J, Poetsch A, Scholtissek A, Oelschlägel M, Schmidt G, Tischler D. On the Enigma of Glutathione-Dependent Styrene Degradation in Gordonia rubripertincta CWB2. Appl Environ Microbiol 2018; 84:e00154-18. [PMID: 29475871 PMCID: PMC5930330 DOI: 10.1128/aem.00154-18] [Citation(s) in RCA: 32] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2018] [Accepted: 02/19/2018] [Indexed: 02/05/2023] Open
Abstract
Among bacteria, only a single styrene-specific degradation pathway has been reported so far. It comprises the activity of styrene monooxygenase, styrene oxide isomerase, and phenylacetaldehyde dehydrogenase, yielding phenylacetic acid as the central metabolite. The alternative route comprises ring-hydroxylating enzymes and yields vinyl catechol as central metabolite, which undergoes meta-cleavage. This was reported to be unspecific and also allows the degradation of benzene derivatives. However, some bacteria had been described to degrade styrene but do not employ one of those routes or only parts of them. Here, we describe a novel "hybrid" degradation pathway for styrene located on a plasmid of foreign origin. As putatively also unspecific, it allows metabolizing chemically analogous compounds (e.g., halogenated and/or alkylated styrene derivatives). Gordonia rubripertincta CWB2 was isolated with styrene as the sole source of carbon and energy. It employs an assembled route of the styrene side-chain degradation and isoprene degradation pathways that also funnels into phenylacetic acid as the central metabolite. Metabolites, enzyme activity, genome, transcriptome, and proteome data reinforce this observation and allow us to understand this biotechnologically relevant pathway, which can be used for the production of ibuprofen.IMPORTANCE The degradation of xenobiotics by bacteria is not only important for bioremediation but also because the involved enzymes are potential catalysts in biotechnological applications. This study reveals a novel degradation pathway for the hazardous organic compound styrene in Gordonia rubripertincta CWB2. This study provides an impressive illustration of horizontal gene transfer, which enables novel metabolic capabilities. This study presents glutathione-dependent styrene metabolization in an (actino-)bacterium. Further, the genomic background of the ability of strain CWB2 to produce ibuprofen is demonstrated.
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Affiliation(s)
- Thomas Heine
- Institute of Biosciences, TU Bergakademie Freiberg, Freiberg, Germany
| | | | - Anne Ballmann
- Institute of Biosciences, TU Bergakademie Freiberg, Freiberg, Germany
| | | | - Christian Rückert
- Technologieplattform Genomik, Centrum für Biotechnologie (CeBiTec), Universität Bielefeld, Bielefeld, Germany
| | - Tobias Busche
- Technologieplattform Genomik, Centrum für Biotechnologie (CeBiTec), Universität Bielefeld, Bielefeld, Germany
| | - Anika Winkler
- Technologieplattform Genomik, Centrum für Biotechnologie (CeBiTec), Universität Bielefeld, Bielefeld, Germany
| | - Jörn Kalinowski
- Technologieplattform Genomik, Centrum für Biotechnologie (CeBiTec), Universität Bielefeld, Bielefeld, Germany
| | - Ansgar Poetsch
- Plant Biochemistry, Ruhr University Bochum, Bochum, Germany
- School of Biomedical and Healthcare Sciences, Plymouth University, Plymouth, United Kingdom
| | - Anika Scholtissek
- Institute of Biosciences, TU Bergakademie Freiberg, Freiberg, Germany
| | | | - Gert Schmidt
- Institut für Keramik, Glas- und Baustofftechnik, TU Bergakademie Freiberg, Freiberg, Germany
| | - Dirk Tischler
- Institute of Biosciences, TU Bergakademie Freiberg, Freiberg, Germany
- Microbial Biotechnology, Ruhr University Bochum, Bochum, Germany
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13
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Guo X, Crnovcic I, Chang CY, Luo J, Lohman JR, Papinski M, Bechthold A, Horsman GP, Shen B. PokMT1 from the Polyketomycin Biosynthetic Machinery of Streptomyces diastatochromogenes Tü6028 Belongs to the Emerging Family of C-Methyltransferases That Act on CoA-Activated Aromatic Substrates. Biochemistry 2018; 57:1003-1011. [PMID: 29341603 DOI: 10.1021/acs.biochem.7b01219] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Recent biochemical characterizations of the MdpB2 CoA ligase and MdpB1 C-methyltransferase (C-MT) from the maduropeptin (MDP, 2) biosynthetic machinery revealed unusual pathway logic involving C-methylation occurring on a CoA-activated aromatic substrate. Here we confirmed this pathway logic for the biosynthesis of polyketomycin (POK, 3). Biochemical characterization unambiguously established that PokM3 and PokMT1 catalyze the sequential conversion of 6-methylsalicylic acid (6-MSA, 4) to form 3,6-dimethylsalicylyl-CoA (3,6-DMSA-CoA, 6), which serves as the direct precursor for the 3,6-dimethylsalicylic acid (3,6-DMSA) moiety in the biosynthesis of 3. PokMT1 catalyzes the C-methylation of 6-methylsalicylyl-CoA (6-MSA-CoA, 5) with a kcat of 1.9 min-1 and a Km of 2.2 ± 0.1 μM, representing the most proficient C-MT characterized to date. Bioinformatics analysis of MTs from natural product biosynthetic machineries demonstrated that PokMT1 and MdpB1 belong to a phylogenetic clade of C-MTs that preferably act on aromatic acids. Significantly, this clade includes the structurally characterized enzyme SibL, which catalyzes C-methylation of 3-hydroxykynurenine in its free acid form, using two conserved tyrosine residues for catalysis. A homology model and site-directed mutagenesis suggested that PokMT1 also employs this unusual arrangement of tyrosine residues to coordinate C-methylation but revealed a large cavity capable of accommodating the CoA moiety tethered to 5. CoA activation of the aromatic acid substrate may represent a general strategy that could be exploited to improve catalytic efficiency. This study sets the stage to further investigate and exploit the catalytic utility of this emerging family of C-MTs in biocatalysis and synthetic biology.
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Affiliation(s)
- Xun Guo
- Department of Chemistry, The Scripps Research Institute , Jupiter, Florida 33458, United States
| | - Ivana Crnovcic
- Department of Chemistry, The Scripps Research Institute , Jupiter, Florida 33458, United States
| | - Chin-Yuan Chang
- Department of Chemistry, The Scripps Research Institute , Jupiter, Florida 33458, United States
| | - Jun Luo
- Department of Chemistry, The Scripps Research Institute , Jupiter, Florida 33458, United States
| | - Jeremy R Lohman
- Department of Chemistry, The Scripps Research Institute , Jupiter, Florida 33458, United States
| | - Monica Papinski
- Department of Chemistry and Biochemistry, Wilfrid Laurier University , Waterloo, ON N2L 3C5, Canada
| | - Andreas Bechthold
- Institute for Pharmaceutical Sciences, Pharmaceutical Biology and Biotechnology, University of Freiburg , Stefan-Meier-Strasse 19, 79104 Freiburg, Germany
| | - Geoffrey P Horsman
- Department of Chemistry and Biochemistry, Wilfrid Laurier University , Waterloo, ON N2L 3C5, Canada
| | - Ben Shen
- Department of Chemistry, The Scripps Research Institute , Jupiter, Florida 33458, United States.,Department of Molecular Medicine, The Scripps Research Institute , Jupiter, Florida 33458, United States.,Natural Products Library Initiative at The Scripps Research Institute, The Scripps Research Institute , Jupiter, Florida 33458, United States
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Schühle K, Nies J, Heider J. An indoleacetate-CoA ligase and a phenylsuccinyl-CoA transferase involved in anaerobic metabolism of auxin. Environ Microbiol 2016; 18:3120-32. [DOI: 10.1111/1462-2920.13347] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2016] [Accepted: 04/15/2016] [Indexed: 12/22/2022]
Affiliation(s)
- Karola Schühle
- Laboratory for Microbiology; Philipps-Universität Marburg; Karl-von-Frisch-Straße 8 35043 Marburg Germany
| | - Jonas Nies
- Laboratory for Microbiology; Philipps-Universität Marburg; Karl-von-Frisch-Straße 8 35043 Marburg Germany
| | - Johann Heider
- Laboratory for Microbiology; Philipps-Universität Marburg; Karl-von-Frisch-Straße 8 35043 Marburg Germany
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15
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Sabra W, Röske I, Sahm K, Antranikian G, Zeng AP. High temperature biogas reactors to treat stillage from an industrial bioethanol process: Metabolic and microbial characterization. Eng Life Sci 2015. [DOI: 10.1002/elsc.201500040] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
Affiliation(s)
- Wael Sabra
- Institute of Bioprocess and Biosystems Engineering; Hamburg University of Technology; Hamburg Germany
| | - Immo Röske
- Institute of Technical Microbiology; Hamburg University of Technology; Hamburg Germany
| | - Kerstin Sahm
- Institute of Technical Microbiology; Hamburg University of Technology; Hamburg Germany
| | - Garabed Antranikian
- Institute of Technical Microbiology; Hamburg University of Technology; Hamburg Germany
| | - An-Ping Zeng
- Institute of Bioprocess and Biosystems Engineering; Hamburg University of Technology; Hamburg Germany
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Structural Organization of Enzymes of the Phenylacetate Catabolic Hybrid Pathway. BIOLOGY 2015; 4:424-42. [PMID: 26075354 PMCID: PMC4498308 DOI: 10.3390/biology4020424] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/10/2015] [Revised: 05/25/2015] [Accepted: 05/29/2015] [Indexed: 11/17/2022]
Abstract
Aromatic compounds are the second most abundant class of molecules on the earth and frequent environmental pollutants. They are difficult to metabolize due to an inert chemical structure, and of all living organisms, only microbes have evolved biochemical pathways that can open an aromatic ring and catabolize thus formed organic molecules. In bacterial genomes, the phenylacetate (PA) utilization pathway is abundant and represents the central route for degradation of a variety of organic compounds, whose degradation reactions converge at this pathway. The PA pathway is a hybrid pathway and combines the dual features of aerobic metabolism, i.e., usage of both oxygen to open the aromatic ring and of anaerobic metabolism—coenzyme A derivatization of PA. This allows the degradation process to be adapted to fluctuating oxygen conditions. In this review we focus on the structural and functional aspects of enzymes and their complexes involved in the PA degradation by the catabolic hybrid pathway. We discuss the ability of the central PaaABCE monooxygenase to reversibly oxygenate PA, the controlling mechanisms of epoxide concentration by the pathway enzymes, and the similarity of the PA utilization pathway to the benzoate utilization Box pathway and β-oxidation of fatty acids.
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17
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In vitro reconstitution of indolmycin biosynthesis reveals the molecular basis of oxazolinone assembly. Proc Natl Acad Sci U S A 2015; 112:2717-22. [PMID: 25730866 DOI: 10.1073/pnas.1419964112] [Citation(s) in RCA: 45] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
The bacterial tryptophanyl-tRNA synthetase inhibitor indolmycin features a unique oxazolinone heterocycle whose biogenetic origins have remained obscure for over 50 years. Here we identify and characterize the indolmycin biosynthetic pathway, using systematic in vivo gene inactivation, in vitro biochemical assays, and total enzymatic synthesis. Our work reveals that a phenylacetate-CoA ligase-like enzyme Ind3 catalyzes an unusual ATP-dependent condensation of indolmycenic acid and dehydroarginine, driving oxazolinone ring assembly. We find that Ind6, which also has chaperone-like properties, acts as a gatekeeper to direct the outcome of this reaction. With Ind6 present, the normal pathway ensues. Without Ind6, the pathway derails to an unusual shunt product. Our work reveals the complete pathway for indolmycin formation and sets the stage for using genetic and chemoenzymatic methods to generate indolmycin derivatives as potential therapeutic agents.
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Ismail W, El-Sayed WS. Degradation of phenylacetate by Acinetobacter spp.: evidence for the phenylacetyl-coenzyme A pathway. ANN MICROBIOL 2013. [DOI: 10.1007/s13213-013-0608-y] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
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19
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Murdoch RW, Hay AG. Genetic and chemical characterization of ibuprofen degradation by Sphingomonas Ibu-2. MICROBIOLOGY (READING, ENGLAND) 2013; 159:621-632. [PMID: 23329679 PMCID: PMC4083657 DOI: 10.1099/mic.0.062273-0] [Citation(s) in RCA: 52] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/21/2012] [Revised: 11/05/2012] [Accepted: 01/14/2013] [Indexed: 01/03/2023]
Abstract
Sphingomonas Ibu-2 has the unusual ability to cleave the acid side chain from the pharmaceutical ibuprofen and related arylacetic acid derivatives to yield corresponding catechols under aerobic conditions via a previously uncharacterized mechanism. Screening a chromosomal library of Ibu-2 DNA in Escherichia coli EPI300 allowed us to identify one fosmid clone (pFOS3G7) that conferred the ability to metabolize ibuprofen to isobutylcatechol. Characterization of pFOS3G7 loss-of-function transposon mutants permitted identification of five ORFs, ipfABDEF, whose predicted amino acid sequences bore similarity to the large and small units of an aromatic dioxygenase (ipfAB), a sterol carrier protein X (SCPx) thiolase (ipfD), a domain of unknown function 35 (DUF35) protein (ipfE) and an aromatic CoA ligase (ipfF). Two additional ORFs, ipfH and ipfI, which encode putative ferredoxin reductase and ferredoxin components of an aromatic dioxygenase system, respectively, were also identified on pFOS3G7. Complementation of a markerless loss-of-function ipfD deletion mutant restored catechol production as did complementation of the ipfF Tn mutant. Expression of subcloned ipfABDEF alone in E. coli did not impart full metabolic activity unless coexpressed with ipfHI. CoA ligation followed by ring oxidation is common to phenylacetic acid pathways. However, the need for a putative SCPx thiolase (IpfD) and DUF35 protein (IpfE) in aerobic arylacetic acid degradation is unprecedented. This work provides preliminary insights into the mechanism behind this novel arylacetic acid-deacylating, catechol-generating activity.
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Affiliation(s)
- Robert W. Murdoch
- Graduate Program in Environmental Toxicology, Institute for Comparative and Environmental Toxicology, Cornell University, Ithaca, NY 14850, USA
| | - Anthony G. Hay
- Graduate Program in Environmental Toxicology, Institute for Comparative and Environmental Toxicology, Cornell University, Ithaca, NY 14850, USA
- Department of Microbiology, B53A Wing Hall, Cornell University, Ithaca, NY 14850, USA
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Grishin AM, Ajamian E, Zhang L, Rouiller I, Bostina M, Cygler M. Protein-protein interactions in the β-oxidation part of the phenylacetate utilization pathway: crystal structure of the PaaF-PaaG hydratase-isomerase complex. J Biol Chem 2012; 287:37986-96. [PMID: 22961985 PMCID: PMC3488069 DOI: 10.1074/jbc.m112.388231] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2012] [Revised: 08/29/2012] [Indexed: 11/06/2022] Open
Abstract
Microbial anaerobic and so-called hybrid pathways for degradation of aromatic compounds contain β-oxidation-like steps. These reactions convert the product of the opening of the aromatic ring to common metabolites. The hybrid phenylacetate degradation pathway is encoded in Escherichia coli by the paa operon containing genes for 10 enzymes. Previously, we have analyzed protein-protein interactions among the enzymes catalyzing the initial oxidation steps in the paa pathway (Grishin, A. M., Ajamian, E., Tao, L., Zhang, L., Menard, R., and Cygler, M. (2011) J. Biol. Chem. 286, 10735-10743). Here we report characterization of interactions between the remaining enzymes of this pathway and show another stable complex, PaaFG, an enoyl-CoA hydratase and enoyl-Coa isomerase, both belonging to the crotonase superfamily. These steps are biochemically similar to the well studied fatty acid β-oxidation, which can be catalyzed by individual monofunctional enzymes, multifunctional enzymes comprising several domains, or enzymatic complexes such as the bacterial fatty acid β-oxidation complex. We have determined the structure of the PaaFG complex and determined that although individually PaaF and PaaG are similar to enzymes from the fatty acid β-oxidation pathway, the structure of the complex is dissimilar from bacterial fatty acid β-oxidation complexes. The PaaFG complex has a four-layered structure composed of homotrimeric discs of PaaF and PaaG. The active sites of PaaF and PaaG are adapted to accept the intermediary components of the Paa pathway, different from those of the fatty acid β-oxidation. The association of PaaF and PaaG into a stable complex might serve to speed up the steps of the pathway following the conversion of phenylacetyl-CoA to a toxic and unstable epoxide-CoA by PaaABCE monooxygenase.
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Affiliation(s)
- Andrey M. Grishin
- From the Department of Biochemistry, University of Saskatchewan, Saskatoon, Saskatchewan S7N 5E5, Canada
| | - Eunice Ajamian
- the Department of Biochemistry, McGill University, Montreal, Quebec H3G 1Y6, Canada
| | - Linhua Zhang
- the Department of Biochemistry, McGill University, Montreal, Quebec H3G 1Y6, Canada
| | - Isabelle Rouiller
- the Department of Anatomy and Cell Biology, McGill University, Montreal, Quebec H3A 2B2, Canada, and
| | - Mihnea Bostina
- Facility for Electron Microscopy Research, McGill University, Montreal, Quebec H3A 2B2, Canada
| | - Miroslaw Cygler
- From the Department of Biochemistry, University of Saskatchewan, Saskatoon, Saskatchewan S7N 5E5, Canada
- the Department of Biochemistry, McGill University, Montreal, Quebec H3G 1Y6, Canada
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21
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Epoxy Coenzyme A Thioester pathways for degradation of aromatic compounds. Appl Environ Microbiol 2012; 78:5043-51. [PMID: 22582071 DOI: 10.1128/aem.00633-12] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Aromatic compounds (biogenic and anthropogenic) are abundant in the biosphere. Some of them are well-known environmental pollutants. Although the aromatic nucleus is relatively recalcitrant, microorganisms have developed various catabolic routes that enable complete biodegradation of aromatic compounds. The adopted degradation pathways depend on the availability of oxygen. Under oxic conditions, microorganisms utilize oxygen as a cosubstrate to activate and cleave the aromatic ring. In contrast, under anoxic conditions, the aromatic compounds are transformed to coenzyme A (CoA) thioesters followed by energy-consuming reduction of the ring. Eventually, the dearomatized ring is opened via a hydrolytic mechanism. Recently, novel catabolic pathways for the aerobic degradation of aromatic compounds were elucidated that differ significantly from the established catabolic routes. The new pathways were investigated in detail for the aerobic bacterial degradation of benzoate and phenylacetate. In both cases, the pathway is initiated by transforming the substrate to a CoA thioester and all the intermediates are bound by CoA. The subsequent reactions involve epoxidation of the aromatic ring followed by hydrolytic ring cleavage. Here we discuss the novel pathways, with a particular focus on their unique features and occurrence as well as ecological significance.
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22
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Genetic analysis of the upper phenylacetate catabolic pathway in the production of tropodithietic acid by Phaeobacter gallaeciensis. Appl Environ Microbiol 2012; 78:3539-51. [PMID: 22407685 DOI: 10.1128/aem.07657-11] [Citation(s) in RCA: 44] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023] Open
Abstract
Production of the antibiotic tropodithietic acid (TDA) depends on the central phenylacetate catabolic pathway, specifically on the oxygenase PaaABCDE, which catalyzes epoxidation of phenylacetyl-coenzyme A (CoA). Our study was focused on genes of the upper part of this pathway leading to phenylacetyl-CoA as precursor for TDA. Phaeobacter gallaeciensis DSM 17395 encodes two genes with homology to phenylacetyl-CoA ligases (paaK1 and paaK2), which were shown to be essential for phenylacetate catabolism but not for TDA biosynthesis and phenylalanine degradation. Thus, in P. gallaeciensis another enzyme must produce phenylacetyl-CoA from phenylalanine. Using random transposon insertion mutagenesis of a paaK1-paaK2 double mutant we identified a gene (ior1) with similarity to iorA and iorB in archaea, encoding an indolepyruvate:ferredoxin oxidoreductase (IOR). The ior1 mutant was unable to grow on phenylalanine, and production of TDA was significantly reduced compared to the wild-type level (60%). Nuclear magnetic resonance (NMR) spectroscopic investigations using (13)C-labeled phenylalanine isotopomers demonstrated that phenylalanine is transformed into phenylacetyl-CoA by Ior1. Using quantitative real-time PCR, we could show that expression of ior1 depends on the adjacent regulator IorR. Growth on phenylalanine promotes production of TDA, induces expression of ior1 (27-fold) and paaK1 (61-fold), and regulates the production of TDA. Phylogenetic analysis showed that the aerobic type of IOR as found in many roseobacters is common within a number of different phylogenetic groups of aerobic bacteria such as Burkholderia, Cupriavidis, and Rhizobia, where it may also contribute to the degradation of phenylalanine.
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23
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Imolorhe IA, Cardona ST. 3-Hydroxyphenylacetic acid induces the Burkholderia cenocepacia phenylacetic acid degradation pathway - toward understanding the contribution of aromatic catabolism to pathogenesis. Front Cell Infect Microbiol 2011; 1:14. [PMID: 22919580 PMCID: PMC3417372 DOI: 10.3389/fcimb.2011.00014] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2011] [Accepted: 11/20/2011] [Indexed: 11/28/2022] Open
Abstract
The phenylacetic acid (PA) degradative pathway is the central pathway by which various aromatic compounds (e.g., styrene) are degraded. Upper pathways for different aromatic compounds converge at common intermediate phenylacetyl-CoA (PA-CoA), which is then metabolized to succinyl-CoA and acetyl-CoA. We previously made a link in Burkholderia cenocepacia between PA degradation and virulence by showing that insertional mutagenesis of paaA and paaE genes, that encode part of a multicomponent oxidase of PA-CoA, results in PA-conditional growth and an attenuated killing phenotype in the Caenorhabditis elegans model of infection. However, insertional mutagenesis of paaK1, which encodes a phenylacetate-CoA ligase, did not result in a PA-conditional growth probably due to the presence of a putative paralog gene paaK2. Recently published crystallographic and enzyme kinetics data comparing the two PaaK ligases showed that PaaK1 is more active than PaaK2 and that the larger binding pocket of PaaK1 can accommodate hydroxylated PA derived molecules such as 3-hydroxyphenylacetic (3-OHPA) acid and 4-hydroxyphenylacetic acid (4-OHPA). The higher activity and broader substrate specificity suggested a more active role in pathogenesis. In this work, we aimed to determine the relevance of PaaK1 activity to the killing ability of B. cenocepacia to C. elegans. Using reporter activity assays, we demonstrate that 3-OHPA activated PA degradation gene promoters of Burkholderia cenocepacia K56-2 in a paaK1-dependent manner, while 4-OHPA had no effect. We compared the pathogenicity of a paaK1 deletion mutant with that of the wild type in C. elegans and observed no differences in the killing ability of the strains. Taken together, these studies suggest that 3-OHPA, but not 4-OHPA, can induce the PA pathway and that this induction is dependent on the paaK1 gene. However, the more active PaaK1 does not play a distinct role in pathogenesis of B. cenocepacia as previously suggested.
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Affiliation(s)
- Ijeme A Imolorhe
- Department of Microbiology, University of Manitoba Winnipeg, MB, Canada
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Law A, Boulanger MJ. Defining a structural and kinetic rationale for paralogous copies of phenylacetate-CoA ligases from the cystic fibrosis pathogen Burkholderia cenocepacia J2315. J Biol Chem 2011; 286:15577-85. [PMID: 21388965 PMCID: PMC3083198 DOI: 10.1074/jbc.m111.219683] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2011] [Revised: 02/07/2011] [Indexed: 11/06/2022] Open
Abstract
The phenylacetic acid (PAA) degradation pathway is the sole aerobic route for phenylacetic acid metabolism in bacteria and facilitates degradation of environmental pollutants such as styrene and ethylbenzene. The PAA pathway also is implicated in promoting Burkholderia cenocepacia infections in cystic fibrosis patients. Intriguingly, the first enzyme in the PAA pathway is present in two copies (paaK1 and paaK2), yet each subsequent enzyme is present in only a single copy. Furthermore, sequence divergence indicates that PaaK1 and PaaK2 form a unique subgroup within the adenylate-forming enzyme (AFE) superfamily. To establish a biochemical rationale for the existence of the PaaK paralogs in B. cenocepacia, we present high resolution x-ray crystal structures of a selenomethionine derivative of PaaK1 in complex with ATP and adenylated phenylacetate intermediate complexes of PaaK1 and PaaK2 in distinct conformations. Structural analysis reveals a novel N-terminal microdomain that may serve to recruit subsequent PAA enzymes, whereas a bifunctional role is proposed for the P-loop in stabilizing the C-terminal domain in conformation 2. The potential for different kinetic profiles was suggested by a structurally divergent extension of the aryl substrate pocket in PaaK1 relative to PaaK2. Functional characterization confirmed this prediction, with PaaK1 possessing a lower K(m) for phenylacetic acid and better able to accommodate 3' and 4' substitutions on the phenyl ring. Collectively, these results offer detailed insight into the reaction mechanism of a novel subgroup of the AFE superfamily and provide a clear biochemical rationale for the presence of paralogous copies of PaaK of B. cenocepacia.
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Affiliation(s)
- Adrienne Law
- From the Department of Biochemistry & Microbiology, University of Victoria, Victoria, British Columbia V8W 3P6, Canada
| | - Martin J. Boulanger
- From the Department of Biochemistry & Microbiology, University of Victoria, Victoria, British Columbia V8W 3P6, Canada
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25
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Griehl C, Hecht C, Streuber S, Ganß Y, Kremp H. Bestimmung von Phenylessigsäure zur Früherkennung von Prozessstörungen in Biogasanlagen. CHEM-ING-TECH 2010. [DOI: 10.1002/cite.200900064] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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Carmona M, Zamarro MT, Blázquez B, Durante-Rodríguez G, Juárez JF, Valderrama JA, Barragán MJL, García JL, Díaz E. Anaerobic catabolism of aromatic compounds: a genetic and genomic view. Microbiol Mol Biol Rev 2009; 73:71-133. [PMID: 19258534 PMCID: PMC2650882 DOI: 10.1128/mmbr.00021-08] [Citation(s) in RCA: 264] [Impact Index Per Article: 17.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Aromatic compounds belong to one of the most widely distributed classes of organic compounds in nature, and a significant number of xenobiotics belong to this family of compounds. Since many habitats containing large amounts of aromatic compounds are often anoxic, the anaerobic catabolism of aromatic compounds by microorganisms becomes crucial in biogeochemical cycles and in the sustainable development of the biosphere. The mineralization of aromatic compounds by facultative or obligate anaerobic bacteria can be coupled to anaerobic respiration with a variety of electron acceptors as well as to fermentation and anoxygenic photosynthesis. Since the redox potential of the electron-accepting system dictates the degradative strategy, there is wide biochemical diversity among anaerobic aromatic degraders. However, the genetic determinants of all these processes and the mechanisms involved in their regulation are much less studied. This review focuses on the recent findings that standard molecular biology approaches together with new high-throughput technologies (e.g., genome sequencing, transcriptomics, proteomics, and metagenomics) have provided regarding the genetics, regulation, ecophysiology, and evolution of anaerobic aromatic degradation pathways. These studies revealed that the anaerobic catabolism of aromatic compounds is more diverse and widespread than previously thought, and the complex metabolic and stress programs associated with the use of aromatic compounds under anaerobic conditions are starting to be unraveled. Anaerobic biotransformation processes based on unprecedented enzymes and pathways with novel metabolic capabilities, as well as the design of novel regulatory circuits and catabolic networks of great biotechnological potential in synthetic biology, are now feasible to approach.
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Affiliation(s)
- Manuel Carmona
- Departamento de Microbiología Molecular, Centro de Investigaciones Biológicas, Consejo Superior de Investigaciones Científicas, Ramiro de Maeztu 9, 28040 Madrid, Spain
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27
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Abstract
Enzymatic activation of PAA (phenylacetic acid) to phenylacetyl-CoA is an important step in the biosynthesis of the beta-lactam antibiotic penicillin G by the fungus Penicillium chrysogenum. CoA esters of PAA and POA (phenoxyacetic acid) act as acyl donors in the exchange of the aminoadipyl side chain of isopenicillin N to produce penicillin G or penicillin V. The phl gene, encoding a PCL (phenylacetate-CoA ligase), was cloned in Escherichia coli as a maltose-binding protein fusion and the biochemical properties of the enzyme were characterized. The recombinant fusion protein converted PAA into phenylacetyl-CoA in an ATP- and magnesium-dependent reaction. PCL could also activate POA, but the catalytic efficiency of the enzyme was rather low with k(cat)/K(m) values of 0.23+/-0.06 and 7.8+/-1.2 mM(-1).s(-1) for PAA and POA respectively. Surprisingly, PCL was very efficient in catalysing the conversion of trans-cinnamic acids to the corresponding CoA thioesters [k(cat)/K(m)=(3.1+/-0.4)x10(2) mM(-1).s(-1) for trans-cinnamic acid]. Of all the substrates screened, medium-chain fatty acids, which also occur as the side chains of the natural penicillins F, DF, H and K, were the best substrates for PCL. The high preference for fatty acids could be explained by a homology model of PCL that was constructed on the basis of sequence similarity with the Japanese firefly luciferase. The results suggest that PCL has evolved from a fatty-acid-activating ancestral enzyme that may have been involved in the beta-oxidation of fatty acids.
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Pérez-Pantoja D, De la Iglesia R, Pieper DH, González B. Metabolic reconstruction of aromatic compounds degradation from the genome of the amazing pollutant-degrading bacteriumCupriavidus necatorJMP134. FEMS Microbiol Rev 2008; 32:736-94. [DOI: 10.1111/j.1574-6976.2008.00122.x] [Citation(s) in RCA: 178] [Impact Index Per Article: 11.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
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Phenylacetate metabolism in thermophiles: characterization of phenylacetate-CoA ligase, the initial enzyme of the hybrid pathway in Thermus thermophilus. Curr Microbiol 2008; 57:27-32. [PMID: 18414813 DOI: 10.1007/s00284-008-9147-3] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2008] [Accepted: 02/13/2008] [Indexed: 10/22/2022]
Abstract
Phenylacetate-CoA ligase (E.C. 6.2.1.30), the initial enzyme in the metabolism of phenylacetate, was studied in Thermus thermophilus strain HB27. Enzymatic activity was upregulated during growth on phenylacetate or phenylalanine. The phenylacetate-CoA ligase gene (paaK) was cloned and heterologously expressed in Escherichia coli and the recombinant protein was purified. The enzyme catalyzed phenylacetate + CoA + MgATP --> phenylacetyl-CoA + AMP + MgPP(i) with a V(max) of 24 micromol/min/mg protein at a temperature optimum of 75 degrees C. The apparent K(m) values for ATP, CoA, and phenylacetate were 6, 30, and 50 microM: , respectively. The protein was highly specific toward phenylacetate and showed only low activity with 4-hydroxyphenylacetate. Despite an amino acid sequence identity of >50% with its mesophilic homologues, phenylacetate-CoA ligase was heat stable. The genome contained further homologues of genes, which are postulated to be involved in the CoA ester-dependent metabolic pathway of phenylacetate (hybrid pathway). Enzymes of this thermophile are expected to be robust and might be useful for further studies of this yet unresolved pathway.
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Abstract
This review describes volatiles released into the air by bacteria growing on defined media. Their occurrence, function, and biosynthesis are discussed, and a total of 308 references are cited. An effort has been made to organize the compounds according to their biosynthetic origin.
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Affiliation(s)
- Stefan Schulz
- Institute of Organic Chemistry, Technical University of Braunschweig, Hagenring 30, 38106, Braunschweig, Germany.
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Song F, Zhuang Z, Finci L, Dunaway-Mariano D, Kniewel R, Buglino JA, Solorzano V, Wu J, Lima CD. Structure, function, and mechanism of the phenylacetate pathway hot dog-fold thioesterase PaaI. J Biol Chem 2006; 281:11028-38. [PMID: 16464851 DOI: 10.1074/jbc.m513896200] [Citation(s) in RCA: 58] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The structure and biochemical function of the hot dog-fold thioesterase PaaI operative in the aerobic phenylacetate degradation pathway are examined. PaaI showed modest activity with phenylacetyl-coenzyme A, suggestive of a role in coenzyme A release from this pathway intermediate in the event of limiting downstream pathway enzymes. Minimal activity was observed with aliphatic acyl-coenzyme A thioesters, which ruled out PaaI function in the lower phenylacetate pathway. PaaI was most active with ring-hydroxylated phenylacetyl-coenzyme A thioesters. The x-ray crystal structure of the Escherichia coli thioesterase is reported and analyzed to define the structural basis of substrate recognition and catalysis. The contributions of catalytic and substrate binding residues, thus, identified were examined through steady-state kinetic analysis of site-directed mutant proteins.
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Affiliation(s)
- Feng Song
- Department of Chemistry, University of New Mexico, Albuquerque, New Mexico 87131, USA
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Gescher J, Eisenreich W, Wörth J, Bacher A, Fuchs G. Aerobic benzoyl-CoA catabolic pathway in Azoarcus evansii: studies on the non-oxygenolytic ring cleavage enzyme. Mol Microbiol 2005; 56:1586-600. [PMID: 15916608 DOI: 10.1111/j.1365-2958.2005.04637.x] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
A novel aerobic benzoate pathway has recently been discovered in various bacteria in which benzoate is first converted to benzoyl-CoA. The further downstream steps are associated with the gene products of the benzoate oxidation gene cluster (box) on the Azoarcus evansii chromosome. Benzoyl-CoA is oxidized to 2,3-dihydro-2,3-dihydroxybenzoyl-CoA (benzoyl-CoA dihydrodiol) by benzoyl-CoA oxygenase/reductase BoxBA in the presence of molecular oxygen. This study identified the next, ring cleaving step catalysed by BoxC. The boxC gene was expressed in a recombinant Escherichia coli strain as a fusion protein with maltose binding protein (BoxC(mal)) and the wild type as well as the recombinant proteins were purified and studied. BoxC catalyses the reaction 2,3-dihydro-2,3-dihydroxybenzoyl-CoA + H(2)O --> 3,4-dehydroadipyl-CoA semialdehyde + HCOOH. This is supported by the following results. Assays containing [ring-(13)C(6)]benzoyl-CoA, benzoyl-CoA oxygenase/reductase, BoxC(mal) protein, NADPH and semicarbazide were analysed directly by NMR spectroscopy and mass spectrometry. The products were identified as the semicarbazone of [2,3,4,5,6-(13)C(5)]3,4-dehydroadipyl-CoA semialdehyde; the missing one-carbon unit being formate. The same reaction mixture without semicarbazide yielded a mixture of the hydrate of [2,3,4,5,6-(13)C(5)]3,4-dehydroadipyl-CoA semialdehyde and [2,3,4,5,6-(13)C(5)]4,5-dehydroadipyl-CoA semialdehyde. BoxC, a 122 kDa homodimeric enzyme (61 kDa subunits), is termed benzoyl-CoA-dihydrodiol lyase. It contains domains characteristic for enoyl-CoA hydratases/isomerases, besides a large central domain with no significant similarity to sequences in the database. The purified protein did not require divalent metals, molecular oxygen or any cosubstrates or coenzymes for activity. The complex reaction is part of a widely distributed new principle of aerobic aromatic metabolism in which all intermediates are coenzyme A thioesters and the actual ring-cleavage reaction does not require molecular oxygen.
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Affiliation(s)
- Johannes Gescher
- Institut für Biologie II, Mikrobiologie, Fakultät für Biologie, Universität Freiburg, Schänzlestrasse 1, D-79104 Freiburg, Germany
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Ishiyama D, Vujaklija D, Davies J. Novel pathway of salicylate degradation by Streptomyces sp. strain WA46. Appl Environ Microbiol 2004; 70:1297-306. [PMID: 15006746 PMCID: PMC368302 DOI: 10.1128/aem.70.3.1297-1306.2004] [Citation(s) in RCA: 69] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
A novel salicylate-degrading Streptomyces sp., strain WA46, was identified by UV fluorescence on solid minimal medium containing salicylate; trace amounts of gentisate were detected by high-pressure liquid chromatography when strain WA46 was grown with salicylate. PCR amplification of WA46 DNA with degenerate primers for gentisate 1,2-dioxygenase (GDO) genes produced an amplicon of the expected size. Sequential PCR with nested GDO primers was then used to identify a salicylate degradation gene cluster in a plasmid library of WA46 chromosomal DNA. The nucleotide sequence of a 13.5-kb insert in recombinant plasmid pWD1 (which was sufficient for the complete degradation of salicylate) showed that nine putative open reading frames (ORFs) (sdgABCDEFGHR) were involved. Plasmid pWD1 derivatives disrupted in each putative gene were transformed into Streptomyces lividans TK64. Disruption of either sdgA or sdgC blocked salicylate degradation; constructs lacking sdgD accumulated gentisate. Cell extracts from Escherichia coli DH5 alpha transformants harboring pUC19 that expressed each of the sdg ORFs showed that conversions of salicylate to salicylyl-coenzyme A (CoA) and salicylyl-CoA to gentisyl-CoA required SdgA and SdgC, respectively. SdgA required CoA and ATP as cofactors, while NADH was required for SdgC activity; SdgC was identified as salicylyl-CoA 5-hydroxylase. Gentisyl-CoA underwent spontaneous cleavage to gentisate and CoA. SdgA behaved as a salicylyl-CoA ligase despite showing amino acid sequence similarity to an AMP-ligase. SdgD was identified as a GDO. These results suggest that Streptomyces sp. strain WA46 degrades salicylate by a novel pathway via a CoA derivative. Two-dimensional polyacrylamide gel electrophoresis and reverse transcriptase-PCR studies indicated that salicylate induced expression of the sdg cluster.
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Affiliation(s)
- Daisuke Ishiyama
- Department of Microbiology and Immunology, University of British Columbia, Vancouver, British Columbia, Canada V6T 1Z3
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Dunn MF, Araíza G, Mora J. Biochemical characterization of a Rhizobium etli monovalent cation-stimulated acyl-coenzyme A carboxylase with a high substrate specificity constant for propionyl-coenzyme A. MICROBIOLOGY-SGM 2004; 150:399-406. [PMID: 14766918 DOI: 10.1099/mic.0.26779-0] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Biotin has a profound effect on the metabolism of rhizobia. It is reported here that the activities of the biotin-dependent enzymes acetyl-coenzyme A carboxylase (ACC; EC 6.4.1.2) and propionyl-coenzyme A carboxylase (PCC; EC 6.4.1.3) are present in all species of the five genera comprising the Rhizobiaceae which were examined. Evidence is presented that the ACC and PCC activities detectable in Rhizobium etli extracts are catalysed by a single acyl-coenzyme A carboxylase. The enzyme from R. etli strain 12-53 was purified 478-fold and displayed its highest activity with propionyl-CoA as substrate, with apparent K(m) and V(max) values of 0.064 mM and 2885 nmol min(-1) (mg protein)(-1), respectively. The enzyme carboxylated acetyl-CoA and butyryl-CoA with apparent K(m) values of 0.392 and 0.144 mM, respectively, and V(max) values of 423 and 268 nmol min(-1) (mg protein)(-1), respectively. K(+), or Cs(+) markedly activated the enzyme, which was essentially inactive in their absence. Electrophoretic analysis indicated that the acyl-CoA carboxylase was composed of a 74 kDa biotin-containing alpha subunit and a 45 kDa biotin-free beta subunit, and gel chromatography indicated a total molecular mass of 620 000 Da. The strong kinetic preference of the enzyme for propionyl-CoA is consistent with its participation in an anaplerotic pathway utilizing this substrate.
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Affiliation(s)
- Michael F Dunn
- Programa de Ingeniería Metabólica, Centro de Investigación sobre Fijación de Nitrógeno, Universidad National Autónoma de México, A. P. 565-A, Cuernavaca, Morelos, Mexico
| | - Gisela Araíza
- Programa de Ingeniería Metabólica, Centro de Investigación sobre Fijación de Nitrógeno, Universidad National Autónoma de México, A. P. 565-A, Cuernavaca, Morelos, Mexico
| | - Jaime Mora
- Programa de Ingeniería Metabólica, Centro de Investigación sobre Fijación de Nitrógeno, Universidad National Autónoma de México, A. P. 565-A, Cuernavaca, Morelos, Mexico
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Kholti A, Plesa M, Cornelis P. A new mini-transposon for in vivo protein epitope tagging: application to Burkholderia multivorans. Res Microbiol 2003; 154:451-5. [PMID: 12892852 DOI: 10.1016/s0923-2508(03)00080-9] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
A short amino acid sequence coding for the mature Pseudomonas aeruginosa OprI lipoprotein was fused to a mini-Tn5 plasposon (mini-transposon with an origin of replication) with tetracycline resistance in order to generate in-frame fusion proteins after transposition. After conjugative transfer to Burkholderia multivorans, clones reacting with an anti-OprI mab were selected. In-frame OprI-tagged proteins were detected and identified for six clones. The six C-tagged proteins were detected by immunoblot. The different mutants had insertions into a histone H1-like coding gene, cspD, encoding a cold-shock protein, dsbC, encoding a putative outer membrane lipoprotein involved in thiol-disulfide exchange, paaE, a ferredoxin-NADPH reductase gene, a gene for the catabolism of propionate, and one encoding an unknown protein.
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Affiliation(s)
- Abdelaziz Kholti
- Laboratory of Microbial Interactions, Vrije Universiteit Brussel, Department of Molecular and Cellular Interactions, Flanders Interuniversity Institute of Biotechnology, Pleinlaan 2, 1050 Brussels, Belgium
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Ismail W, El-Said Mohamed M, Wanner BL, Datsenko KA, Eisenreich W, Rohdich F, Bacher A, Fuchs G. Functional genomics by NMR spectroscopy. Phenylacetate catabolism in Escherichia coli. EUROPEAN JOURNAL OF BIOCHEMISTRY 2003; 270:3047-54. [PMID: 12846838 DOI: 10.1046/j.1432-1033.2003.03683.x] [Citation(s) in RCA: 73] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Aerobic metabolism of phenylalanine in most bacteria proceeds via oxidation to phenylacetate. Surprisingly, the further metabolism of phenylacetate has not been elucidated, even in well studied bacteria such as Escherichia coli. The only committed step is the conversion of phenylacetate into phenylacetyl-CoA. The paa operon of E. coli encodes 14 polypeptides involved in the catabolism of phenylacetate. We have found that E. coli K12 mutants with a deletion of the paaF, paaG, paaH, paaJ or paaZ gene are unable to grow with phenylacetate as carbon source. Incubation of a paaG mutant with [U-13C8]phenylacetate yielded ring-1,2-dihydroxy-1,2-dihydrophenylacetyl lactone as shown by NMR spectroscopy. Incubation of the paaF and paaH mutants with phenylacetate yielded delta3-dehydroadipate and 3-hydroxyadipate, respectively. The origin of the carbon atoms of these C6 compounds from the aromatic ring was shown using [ring-13C6]phenylacetate. The paaG and paaZ mutants also converted phenylacetate into ortho-hydroxyphenylacetate, which was previously identified as a dead end product of phenylacetate catabolism. These data, in conjunction with protein sequence data, suggest a novel catabolic pathway via CoA thioesters. According to this, phenylacetyl-CoA is attacked by a ring-oxygenase/reductase (PaaABCDE proteins), generating a hydroxylated and reduced derivative of phenylacetyl-CoA, which is not re-oxidized to a dihydroxylated aromatic intermediate, as in other known aromatic pathways. Rather, it is proposed that this nonaromatic intermediate CoA ester is further metabolized in a complex reaction sequence comprising enoyl-CoA isomerization/hydration, nonoxygenolytic ring opening, and dehydrogenation catalyzed by the PaaG and PaaZ proteins. The subsequent beta-oxidation-type degradation of the resulting CoA dicarboxylate via beta-ketoadipyl-CoA to succinyl-CoA and acetyl-CoA appears to be catalyzed by the PaaJ, PaaF and PaaH proteins.
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Affiliation(s)
- Wael Ismail
- Mikrobiologie, Institut für Biologie II, Universität Freiburg, Germany
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Díaz E, Ferrández A, Prieto MA, García JL. Biodegradation of aromatic compounds by Escherichia coli. Microbiol Mol Biol Rev 2001; 65:523-69, table of contents. [PMID: 11729263 PMCID: PMC99040 DOI: 10.1128/mmbr.65.4.523-569.2001] [Citation(s) in RCA: 288] [Impact Index Per Article: 12.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Although Escherichia coli has long been recognized as the best-understood living organism, little was known about its abilities to use aromatic compounds as sole carbon and energy sources. This review gives an extensive overview of the current knowledge of the catabolism of aromatic compounds by E. coli. After giving a general overview of the aromatic compounds that E. coli strains encounter and mineralize in the different habitats that they colonize, we provide an up-to-date status report on the genes and proteins involved in the catabolism of such compounds, namely, several aromatic acids (phenylacetic acid, 3- and 4-hydroxyphenylacetic acid, phenylpropionic acid, 3-hydroxyphenylpropionic acid, and 3-hydroxycinnamic acid) and amines (phenylethylamine, tyramine, and dopamine). Other enzymatic activities acting on aromatic compounds in E. coli are also reviewed and evaluated. The review also reflects the present impact of genomic research and how the analysis of the whole E. coli genome reveals novel aromatic catabolic functions. Moreover, evolutionary considerations derived from sequence comparisons between the aromatic catabolic clusters of E. coli and homologous clusters from an increasing number of bacteria are also discussed. The recent progress in the understanding of the fundamentals that govern the degradation of aromatic compounds in E. coli makes this bacterium a very useful model system to decipher biochemical, genetic, evolutionary, and ecological aspects of the catabolism of such compounds. In the last part of the review, we discuss strategies and concepts to metabolically engineer E. coli to suit specific needs for biodegradation and biotransformation of aromatics and we provide several examples based on selected studies. Finally, conclusions derived from this review may serve as a lead for future research and applications.
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Affiliation(s)
- E Díaz
- Department of Molecular Microbiology, Centro de Investigaciones Biológicas, Consejo Superior de Investigaciones Científicas, 28006 Madrid, Spain.
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Schühle K, Jahn M, Ghisla S, Fuchs G. Two similar gene clusters coding for enzymes of a new type of aerobic 2-aminobenzoate (anthranilate) metabolism in the bacterium Azoarcus evansii. J Bacteriol 2001; 183:5268-78. [PMID: 11514509 PMCID: PMC95408 DOI: 10.1128/jb.183.18.5268-5278.2001] [Citation(s) in RCA: 52] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
In the beta-proteobacterium Azoarcus evansii, the aerobic metabolism of 2-aminobenzoate (anthranilate), phenylacetate, and benzoate proceeds via three unprecedented pathways. The pathways have in common that all three substrates are initially activated to coenzyme A (CoA) thioesters and further processed in this form. The two initial steps of 2-aminobenzoate metabolism are catalyzed by a 2-aminobenzoate-CoA ligase forming 2-aminobenzoyl-CoA and by a 2-aminobenzoyl-CoA monooxygenase/reductase (ACMR) forming 2-amino-5-oxo-cyclohex-1-ene-1-carbonyl-CoA. Eight genes possibly involved in this pathway, including the genes encoding 2-aminobenzoate-CoA ligase and ACMR, were detected, cloned, and sequenced. The sequence of the ACMR gene showed that this enzyme is an 87-kDa fusion protein of two flavoproteins, a monooxygenase (similar to salicylate monooxygenase) and a reductase (similar to old yellow enzyme). Besides the genes for the initial two enzymes, genes for three enzymes of a beta-oxidation pathway were found. A substrate binding protein of an ABC transport system, a MarR-like regulator, and a putative translation inhibitor protein were also encoded by the gene cluster. The data suggest that, after monooxygenation/reduction of 2-aminobenzoyl-CoA, the nonaromatic CoA thioester intermediate is metabolized further by beta-oxidation. This implies that all subsequent intermediates are CoA thioesters and that the alicyclic carbon ring is not cleaved oxygenolytically. Surprisingly, the cluster of eight genes, which form an operon, is duplicated. The two copies differ only marginally within the coding regions but differ substantially in the respective intergenic regions. Both copies of the genes are coordinately expressed in cells grown aerobically on 2-aminobenzoate.
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Affiliation(s)
- K Schühle
- Mikrobiologie, Institut für Biologie II, Albert-Ludwigs-Universität Freiburg, Freiburg, Germany
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Zaar A, Eisenreich W, Bacher A, Fuchs G. A novel pathway of aerobic benzoate catabolism in the bacteria Azoarcus evansii and Bacillus stearothermophilus. J Biol Chem 2001; 276:24997-5004. [PMID: 11306574 DOI: 10.1074/jbc.m100291200] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The aerobic catabolism of benzoate was studied in the Gram-negative proteobacterium Azoarcus evansii and in the Gram-positive bacterium Bacillus stearothermophilus. In contrast to earlier proposals, benzoate was not converted into hydroxybenzoate or gentisate. Rather, benzoyl-CoA was a product of benzoate catabolism in both microbial species under aerobic conditions in vivo. Benzoyl-CoA was converted into various CoA thioesters by cell extracts of both species in oxygen- and NADPH-dependent reactions. Using [ring-(13)C(6)]benzoyl-CoA as substrate, cis-3,4-[2,3,4,5,6-(13)C(5)]dehydroadipyl-CoA, trans-2,3-[2,3,4,5,6-(13)C(5)]dehydroadipyl-CoA, the 3,6-lactone of 3-[2,3,4,5,6-(13)C(5)]hydroxyadipyl-CoA, and 3-[2,3,4,5,6-(13)C(5)]hydroxyadipyl-CoA were identified as products by NMR spectroscopy. A protein mixture of A. evansii transformed [ring-(13)C(6)]benzoyl-CoA in an NADPH- and oxygen-dependent reaction into 6-[2,3,4,5,6-(13)C(5)]hydroxy-3-hexenoyl-CoA. The data suggest a novel aerobic pathway of benzoate catabolism via CoA intermediates leading to beta-ketoadipyl-CoA, an intermediate of the known beta-ketoadipate pathway.
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Affiliation(s)
- A Zaar
- Institut für Biologie II, Mikrobiologie, Universität Freiburg, Schänzlestrasse 1, D-79104 Freiburg, Germany
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Mohamed ME, Zaar A, Ebenau-Jehle C, Fuchs G. Reinvestigation of a new type of aerobic benzoate metabolism in the proteobacterium Azoarcus evansii. J Bacteriol 2001; 183:1899-908. [PMID: 11222587 PMCID: PMC95084 DOI: 10.1128/jb.183.6.1899-1908.2001] [Citation(s) in RCA: 44] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The aerobic metabolism of benzoate in the proteobacterium Azoarcus evansii was reinvestigated. The known pathways leading to catechol or protocatechuate do not operate in this bacterium. The presumed degradation via 3-hydroxybenzoyl-coenzyme A (CoA) and gentisate could not be confirmed. The first committed step is the activation of benzoate to benzoyl-CoA by a specifically induced benzoate-CoA ligase (AMP forming). This enzyme was purified and shown to differ from an isoenzyme catalyzing the same reaction under anaerobic conditions. The second step postulated involves the hydroxylation of benzoyl-CoA to a so far unknown product by a novel benzoyl-CoA oxygenase, presumably a multicomponent enzyme system. An iron-sulfur flavoprotein, which may be a component of this system, was purified and characterized. The homodimeric enzyme had a native molecular mass of 98 kDa as determined by gel filtration and contained 0.72 mol flavin adenine dinucleotide (FAD), 10.4 to 18.4 mol of Fe, and 13.3 to 17.9 mol of acid-labile sulfur per mol of native protein, depending on the method of protein determination. This benzoate-induced enzyme catalyzed a benzoyl-CoA-, FAD-, and O2-dependent NADPH oxidation surprisingly without hydroxylation of the aromatic ring; however, H2O2 was formed. The gene (boxA, for benzoate oxidation) coding for this protein was cloned and sequenced. It coded for a protein of 46 kDa with two amino acid consensus sequences for two [4Fe-4S] centers at the N terminus. The deduced amino acid sequence showed homology with subunits of ferredoxin-NADP reductase, nitric oxide synthase, NADPH-cytochrome P450 reductase, and phenol hydroxylase. Upstream of the boxA gene, another gene, boxB, encoding a protein of 55 kDa was found. The boxB gene exhibited homology to open reading frames in various other bacteria which code for components of a putative aerobic phenylacetyl-CoA oxidizing system. The boxB gene product was one of at least five proteins induced when A. evansii was grown on benzoate.
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Affiliation(s)
- M E Mohamed
- Mikrobiologie, Institut Biologie II, Universität Freiburg, Freiburg, Germany
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