1
|
Fernández-Arévalo U, Fuchs J, Boll M, Díaz E. Transcriptional regulation of the anaerobic 3-hydroxybenzoate degradation pathway in Aromatoleum sp. CIB. Microbiol Res 2024; 288:127882. [PMID: 39216330 DOI: 10.1016/j.micres.2024.127882] [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: 05/07/2024] [Revised: 07/31/2024] [Accepted: 08/17/2024] [Indexed: 09/04/2024]
Abstract
Phenolic compounds are commonly found in anoxic environments, where they serve as both carbon and energy sources for certain anaerobic bacteria. The anaerobic breakdown of m-cresol, catechol, and certain lignin-derived compounds yields the central intermediate 3-hydroxybenzoate/3-hydroxybenzoyl-CoA. In this study, we have characterized the transcription and regulation of the hbd genes responsible for the anaerobic degradation of 3-hydroxybenzoate in the β-proteobacterium Aromatoleum sp. CIB. The hbd cluster is organized in three catabolic operons and a regulatory hbdR gene that encodes a dimeric transcriptional regulator belonging to the TetR family. HbdR suppresses the activity of the three catabolic promoters (PhbdN, PhbdE and PhbdH) by binding to a conserved palindromic operator box (ATGAATGAN4TCATTCAT). 3-Hydroxybenzoyl-CoA, the initial intermediate of the 3-hydroxybenzoate degradation pathway, along with benzoyl-CoA, serve as effector molecules that bind to HbdR inducing the expression of the hbd genes. Moreover, the hbd genes are subject to additional regulation influenced by the presence of non-aromatic carbon sources (carbon catabolite repression), and their expression is induced in oxygen-deprived conditions by the AcpR transcriptional activator. The prevalence of the hbd cluster among members of the Aromatoleum/Thauera bacterial group, coupled with its association with mobile genetic elements, suggests acquisition through horizontal gene transfer. These findings significantly enhance our understanding of the regulatory mechanisms governing the hbd gene cluster in bacteria, paving the way for further exploration into the anaerobic utilization/valorization of phenolic compounds derived from lignin.
Collapse
Affiliation(s)
- Unai Fernández-Arévalo
- Department of Microbial and Plant Biotechnology, Centro de Investigaciones Biológicas Margarita Salas-CSIC, Madrid, Spain
| | - Jonathan Fuchs
- Faculty of Biology-Microbiology, University of Freiburg, Freiburg, Germany
| | - Matthias Boll
- Faculty of Biology-Microbiology, University of Freiburg, Freiburg, Germany
| | - Eduardo Díaz
- Department of Microbial and Plant Biotechnology, Centro de Investigaciones Biológicas Margarita Salas-CSIC, Madrid, Spain.
| |
Collapse
|
2
|
Richardson BC, Turlington ZR, Vaz Ferreira de Macedo S, Phillips SK, Perry K, Brancato SG, Cooke EW, Gwilt JR, Dasovich MA, Roering AJ, Rossi FM, Snider MJ, French JB, Hicks KA. Structural and Functional Characterization of a Novel Class A Flavin Monooxygenase from Bacillus niacini. Biochemistry 2024. [PMID: 39265075 DOI: 10.1021/acs.biochem.4c00306] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/14/2024]
Abstract
A gene cluster responsible for the degradation of nicotinic acid (NA) in Bacillus niacini has recently been identified, and the structures and functions of the resulting enzymes are currently being evaluated to establish pathway intermediates. One of the genes within this cluster encodes a flavin monooxygenase (BnFMO) that is hypothesized to catalyze a hydroxylation reaction. Kinetic analyses of the recombinantly purified BnFMO suggest that this enzyme catalyzes the hydroxylation of 2,6-dihydroxynicotinic acid (2,6-DHNA) or 2,6-dihydroxypyridine (2,6-DHP), which is formed spontaneously by the decarboxylation of 2,6-DHNA. To understand the details of this hydroxylation reaction, we determined the structure of BnFMO using a multimodel approach combining protein X-ray crystallography and cryo-electron microscopy (cryo-EM). A liganded BnFMO cryo-EM structure was obtained in the presence of 2,6-DHP, allowing us to make predictions about potential catalytic residues. The structural data demonstrate that BnFMO is trimeric, which is unusual for Class A flavin monooxygenases. In both the electron density and coulomb potential maps, a region at the trimeric interface was observed that was consistent with and modeled as lipid molecules. High-resolution mass spectral analysis suggests that there is a mixture of phosphatidylethanolamine and phosphatidylglycerol lipids present. Together, these data provide insights into the molecular details of the central hydroxylation reaction unique to the aerobic degradation of NA in Bacillus niacini.
Collapse
Affiliation(s)
- Brian C Richardson
- The Hormel Institute, University of Minnesota, Austin, Minnesota 55912, United States
| | - Zachary R Turlington
- Department of Chemistry, State University of New York at Cortland, Cortland, New York 13045, United States
| | | | - Sara K Phillips
- Department of Chemistry, State University of New York at Cortland, Cortland, New York 13045, United States
| | - Kay Perry
- NE-CAT and Department of Chemistry and Chemical Biology, Cornell University, Argonne National Laboratory, Argonne, Illinois 60439, United States
| | - Savannah G Brancato
- Department of Chemistry, State University of New York at Cortland, Cortland, New York 13045, United States
| | - Emmalee W Cooke
- Department of Chemistry, State University of New York at Cortland, Cortland, New York 13045, United States
- Department of Chemistry, the College of Wooster, Wooster, Ohio 44691, United States
| | - Jonathan R Gwilt
- Department of Chemistry, State University of New York at Cortland, Cortland, New York 13045, United States
| | - Morgan A Dasovich
- Department of Chemistry, the College of Wooster, Wooster, Ohio 44691, United States
| | - Andrew J Roering
- Department of Chemistry, State University of New York at Cortland, Cortland, New York 13045, United States
| | - Francis M Rossi
- Department of Chemistry, State University of New York at Cortland, Cortland, New York 13045, United States
| | - Mark J Snider
- Department of Chemistry, the College of Wooster, Wooster, Ohio 44691, United States
| | - Jarrod B French
- The Hormel Institute, University of Minnesota, Austin, Minnesota 55912, United States
| | - Katherine A Hicks
- Department of Chemistry, State University of New York at Cortland, Cortland, New York 13045, United States
| |
Collapse
|
3
|
Höing L, Sowa ST, Toplak M, Reinhardt JK, Jakob R, Maier T, Lill MA, Teufel R. Biosynthesis of the bacterial antibiotic 3,7-dihydroxytropolone through enzymatic salvaging of catabolic shunt products. Chem Sci 2024; 15:7749-7756. [PMID: 38784727 PMCID: PMC11110157 DOI: 10.1039/d4sc01715c] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2024] [Accepted: 04/21/2024] [Indexed: 05/25/2024] Open
Abstract
The non-benzenoid aromatic tropone ring is a structural motif of numerous microbial and plant natural products with potent bioactivities. In bacteria, tropone biosynthesis involves early steps of the widespread CoA-dependent phenylacetic acid (paa) catabolon, from which a shunt product is sequestered and surprisingly further utilized as a universal precursor for structurally and functionally diverse tropone derivatives such as tropodithietic acid or (hydroxy)tropolones. Here, we elucidate the biosynthesis of the antibiotic 3,7-dihydroxytropolone in Actinobacteria by in vitro pathway reconstitution using paa catabolic enzymes as well as dedicated downstream tailoring enzymes, including a thioesterase (TrlF) and two flavoprotein monooxygenases (TrlCD and TrlE). We furthermore mechanistically and structurally characterize the multifunctional key enzyme TrlE, which mediates an unanticipated ipso-substitution involving a hydroxylation and subsequent decarboxylation of the CoA-freed side chain, followed by ring oxidation to afford tropolone. This study showcases a remarkably efficient strategy for 3,7-dihydroxytropolone biosynthesis and illuminates the functions of the involved biosynthetic enzymes.
Collapse
Affiliation(s)
- Lars Höing
- Pharmaceutical Biology, Department of Pharmaceutical Sciences, University of Basel Klingelbergstrasse 50 4056 Basel Switzerland
| | - Sven T Sowa
- Pharmaceutical Biology, Department of Pharmaceutical Sciences, University of Basel Klingelbergstrasse 50 4056 Basel Switzerland
| | - Marina Toplak
- Hilde-Mangold-Haus (CIBSS), University of Freiburg Habsburgerstrasse 49 79104 Freiburg im Breisgau Germany
| | - Jakob K Reinhardt
- Pharmaceutical Biology, Department of Pharmaceutical Sciences, University of Basel Klingelbergstrasse 50 4056 Basel Switzerland
| | - Roman Jakob
- Biozentrum, University of Basel Spitalstrasse 41 4056 Basel Switzerland
| | - Timm Maier
- Biozentrum, University of Basel Spitalstrasse 41 4056 Basel Switzerland
| | - Markus A Lill
- Computational Pharmacy, Department of Pharmaceutical Sciences, University of Basel Klingelbergstrasse 50 4056 Basel Switzerland
| | - Robin Teufel
- Pharmaceutical Biology, Department of Pharmaceutical Sciences, University of Basel Klingelbergstrasse 50 4056 Basel Switzerland
| |
Collapse
|
4
|
Ouyang X, Liu G, Guo L, Wu G, Xu P, Zhao YL, Tang H. A multifunctional flavoprotein monooxygenase HspB for hydroxylation and C-C cleavage of 6-hydroxy-3-succinoyl-pyridine. Appl Environ Microbiol 2024; 90:e0225523. [PMID: 38415602 PMCID: PMC10952382 DOI: 10.1128/aem.02255-23] [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: 12/14/2023] [Accepted: 01/26/2024] [Indexed: 02/29/2024] Open
Abstract
Flavoprotein monooxygenases catalyze reactions, including hydroxylation and epoxidation, involved in the catabolism, detoxification, and biosynthesis of natural substrates and industrial contaminants. Among them, the 6-hydroxy-3-succinoyl-pyridine (HSP) monooxygenase (HspB) from Pseudomonas putida S16 facilitates the hydroxylation and C-C bond cleavage of the pyridine ring in nicotine. However, the mechanism for biodegradation remains elusive. Here, we refined the crystal structure of HspB and elucidated the detailed mechanism behind the oxidative hydroxylation and C-C cleavage processes. Leveraging structural information about domains for binding the cofactor flavin adenine dinucleotide (FAD) and HSP substrate, we used molecular dynamics simulations and quantum/molecular mechanics calculations to demonstrate that the transfer of an oxygen atom from the reactive FAD peroxide species (C4a-hydroperoxyflavin) to the C3 atom in the HSP substrate constitutes a rate-limiting step, with a calculated reaction barrier of about 20 kcal/mol. Subsequently, the hydrogen atom was rebounded to the FAD cofactor, forming C4a-hydroxyflavin. The residue Cys218 then catalyzed the subsequent hydrolytic process of C-C cleavage. Our findings contribute to a deeper understanding of the versatile functions of flavoproteins in the natural transformation of pyridine and HspB in nicotine degradation.IMPORTANCEPseudomonas putida S16 plays a pivotal role in degrading nicotine, a toxic pyridine derivative that poses significant environmental challenges. This study highlights a key enzyme, HspB (6-hydroxy-3-succinoyl-pyridine monooxygenase), in breaking down nicotine through the pyrrolidine pathway. Utilizing dioxygen and a flavin adenine dinucleotide cofactor, HspB hydroxylates and cleaves the substrate's side chain. Structural analysis of the refined HspB crystal structure, combined with state-of-the-art computations, reveals its distinctive mechanism. The crucial function of Cys218 was never discovered in its homologous enzymes. Our findings not only deepen our understanding of bacterial nicotine degradation but also open avenues for applications in both environmental cleanup and pharmaceutical development.
Collapse
Affiliation(s)
- Xingyu Ouyang
- State Key Laboratory of Microbial Metabolism, Joint International Research Laboratory of Metabolic and Developmental Sciences, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai, China
| | - Gongquan Liu
- State Key Laboratory of Microbial Metabolism, Joint International Research Laboratory of Metabolic and Developmental Sciences, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai, China
| | - Lihua Guo
- State Key Laboratory of Microbial Metabolism, Joint International Research Laboratory of Metabolic and Developmental Sciences, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai, China
| | - Geng Wu
- State Key Laboratory of Microbial Metabolism, Joint International Research Laboratory of Metabolic and Developmental Sciences, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai, China
| | - Ping Xu
- State Key Laboratory of Microbial Metabolism, Joint International Research Laboratory of Metabolic and Developmental Sciences, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai, China
| | - Yi-Lei Zhao
- State Key Laboratory of Microbial Metabolism, Joint International Research Laboratory of Metabolic and Developmental Sciences, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai, China
| | - Hongzhi Tang
- State Key Laboratory of Microbial Metabolism, Joint International Research Laboratory of Metabolic and Developmental Sciences, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai, China
| |
Collapse
|
5
|
Turlington ZR, Vaz Ferreira de Macedo S, Perry K, Belsky SL, Faust JA, Snider MJ, Hicks KA. Ligand bound structure of a 6-hydroxynicotinic acid 3-monooxygenase provides mechanistic insights. Arch Biochem Biophys 2024; 752:109859. [PMID: 38104959 DOI: 10.1016/j.abb.2023.109859] [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: 10/31/2023] [Revised: 12/08/2023] [Accepted: 12/11/2023] [Indexed: 12/19/2023]
Abstract
6-Hydroxynicotinic acid 3-monooxygenase (NicC) is a bacterial enzyme involved in the degradation of nicotinic acid. This enzyme is a Class A flavin-dependent monooxygenase that catalyzes a unique decarboxylative hydroxylation. The unliganded structure of this enzyme has previously been reported and studied using steady- and transient-state kinetics to support a comprehensive kinetic mechanism. Here we report the crystal structure of the H47Q NicC variant in both a ligand-bound (solved to 2.17 Å resolution) and unliganded (1.51 Å resolution) form. Interestingly, in the liganded form, H47Q NicC is bound to 2-mercaptopyridine (2-MP), a contaminant present in the commercial stock of 6-mercaptopyridine-3-carboxylic acid(6-MNA), a substrate analogue. 2-MP binds weakly to H47Q NicC and is not a substrate for the enzyme. Based on kinetic and thermodynamic characterization, we have fortuitously captured a catalytically inactive H47Q NicC•2-MP complex in our crystal structure. This complex reveals interesting mechanistic details about the reaction catalyzed by 6-hydroxynicotinic acid 3-monooxygenase.
Collapse
Affiliation(s)
- Zachary R Turlington
- Department of Chemistry, State University of New York at Cortland, Cortland, NY, 13045, United States
| | | | - Kay Perry
- NE-CAT and Department of Chemistry and Chemical Biology, Cornell University, Argonne National Laboratory, Argonne, IL, United States
| | - Sam L Belsky
- Department of Chemistry, The College of Wooster, Wooster, OH, 44691, United States
| | - Jennifer A Faust
- Department of Chemistry, The College of Wooster, Wooster, OH, 44691, United States
| | - Mark J Snider
- Department of Chemistry, The College of Wooster, Wooster, OH, 44691, United States
| | - Katherine A Hicks
- Department of Chemistry, State University of New York at Cortland, Cortland, NY, 13045, United States.
| |
Collapse
|
6
|
Pereira MS, de Araújo SS, Nagem RAP, Richard JP, Brandão TAS. The role of remote flavin adenine dinucleotide pieces in the oxidative decarboxylation catalyzed by salicylate hydroxylase. Bioorg Chem 2022; 119:105561. [PMID: 34965488 PMCID: PMC8824312 DOI: 10.1016/j.bioorg.2021.105561] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2021] [Revised: 11/19/2021] [Accepted: 12/11/2021] [Indexed: 02/03/2023]
Abstract
Salicylate hydroxylase (NahG) has a single redox site in which FAD is reduced by NADH, the O2 is activated by the reduced flavin, and salicylate undergoes an oxidative decarboxylation by a C(4a)-hydroperoxyflavin intermediate to give catechol. We report experimental results that show the contribution of individual pieces of the FAD cofactor to the observed enzymatic activity for turnover of the whole cofactor. A comparison of the kinetic parameters and products for the NahG-catalyzed reactions of FMN and riboflavin cofactor fragments reveal that the adenosine monophosphate (AMP) and ribitol phosphate pieces of FAD act to anchor the flavin to the enzyme and to direct the partitioning of the C(4a)-hydroperoxyflavin reaction intermediate towards hydroxylation of salicylate. The addition of AMP or ribitol phosphate pieces to solutions of the truncated flavins results in a partial restoration of the enzymatic activity lost upon truncation of FAD, and the pieces direct the reaction of the C(4a)-hydroperoxyflavin intermediate towards hydroxylation of salicylate.
Collapse
Affiliation(s)
- Mozart S. Pereira
- Departamento de Química, Instituto de Ciências Exatas, Universidade Federal de Minas Gerais, Belo Horizonte, MG 31270-901, Brazil
| | - Simara S. de Araújo
- Departamento de Bioquímica e Imunologia, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Belo Horizonte, MG 31270-901, Brazil
| | - Ronaldo A. P. Nagem
- Departamento de Bioquímica e Imunologia, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Belo Horizonte, MG 31270-901, Brazil
| | - John P. Richard
- Department of Chemistry, University at Buffalo, SUNY, Buffalo, New York 14260-3000,CORRESPONDING AUTHOR: ;
| | - Tiago A. S. Brandão
- Departamento de Química, Instituto de Ciências Exatas, Universidade Federal de Minas Gerais, Belo Horizonte, MG 31270-901, Brazil.,CORRESPONDING AUTHOR: ;
| |
Collapse
|
7
|
Meng L, Sun C, Gao L, Saleem M, Li B, Wang C. Hydroxybenzoate hydroxylase genes underlying protocatechuic acid production in Valsa mali are required for full pathogenicity in apple trees. MOLECULAR PLANT PATHOLOGY 2021; 22:1370-1382. [PMID: 34390112 PMCID: PMC8518569 DOI: 10.1111/mpp.13119] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 04/26/2021] [Revised: 07/01/2021] [Accepted: 07/20/2021] [Indexed: 06/13/2023]
Abstract
Valsa mali is the causative agent of apple tree valsa canker, which causes significant losses in apple production. It produces various toxic compounds that kill plant cells, facilitating infection. Among these, protocatechuic acid exhibits the highest phytotoxic activity. However, those genes involved in toxin production have not been studied. In this study we identified four hydroxybenzoate hydroxylase genes (VmHbh1, VmHbh2, VmHbh3, and VmHbh4) from the transcriptome of V. mali. The VmHbh protein had high enzymatic activities of hydroxybenzoate hydroxylase, which could convert 4-hydroxybenzoate to protocatechuic acid. These four VmHbh genes all had highly elevated transcript levels during the V. mali infection process, especially VmHbh1 and VmHbh4, with 26.0- and 53.4-fold increases, respectively. Mutants of the four genes were generated to study whether VmHbhs are required for V. mali pathogenicity. Of the four genes, the VmHbh1 and VmHbh4 deletion mutants considerably attenuated V. mali virulence in apple leaves and in twigs, coupled with much reduced toxin levels. The VmHbh2 and VmHbh3 deletion mutants promoted the transcript levels of the other VmHbhs, suggesting functional redundancies of VmHbhs in V. mali virulence. The results provide insights into the functions of VmHbhs in the production of protocatechuic acid by V. mali during its infection of apple trees.
Collapse
Affiliation(s)
- Lulu Meng
- College of Plant Health and MedicineKey Laboratory of Integrated Crop Pest Management of Shandong ProvinceShandong Province Key Laboratory of Applied MycologyQingdao Agricultural UniversityQingdaoChina
| | - Cuicui Sun
- College of Plant Health and MedicineKey Laboratory of Integrated Crop Pest Management of Shandong ProvinceShandong Province Key Laboratory of Applied MycologyQingdao Agricultural UniversityQingdaoChina
| | - Liyong Gao
- College of Plant Health and MedicineKey Laboratory of Integrated Crop Pest Management of Shandong ProvinceShandong Province Key Laboratory of Applied MycologyQingdao Agricultural UniversityQingdaoChina
| | - Muhammad Saleem
- Department of Biological SciencesAlabama State UniversityMontgomeryAlabamaUSA
| | - Baohua Li
- College of Plant Health and MedicineKey Laboratory of Integrated Crop Pest Management of Shandong ProvinceShandong Province Key Laboratory of Applied MycologyQingdao Agricultural UniversityQingdaoChina
| | - Caixia Wang
- College of Plant Health and MedicineKey Laboratory of Integrated Crop Pest Management of Shandong ProvinceShandong Province Key Laboratory of Applied MycologyQingdao Agricultural UniversityQingdaoChina
| |
Collapse
|
8
|
Liu Z, Zhao F, Zhao B, Yang J, Ferrara J, Sankaran B, Venkataram Prasad BV, Kundu BB, Phillips GN, Gao Y, Hu L, Zhu T, Gao X. Structural basis of the stereoselective formation of the spirooxindole ring in the biosynthesis of citrinadins. Nat Commun 2021; 12:4158. [PMID: 34230497 PMCID: PMC8260726 DOI: 10.1038/s41467-021-24421-0] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2021] [Accepted: 06/17/2021] [Indexed: 11/09/2022] Open
Abstract
Prenylated indole alkaloids featuring spirooxindole rings possess a 3R or 3S carbon stereocenter, which determines the bioactivities of these compounds. Despite the stereoselective advantages of spirooxindole biosynthesis compared with those of organic synthesis, the biocatalytic mechanism for controlling the 3R or 3S-spirooxindole formation has been elusive. Here, we report an oxygenase/semipinacolase CtdE that specifies the 3S-spirooxindole construction in the biosynthesis of 21R-citrinadin A. High-resolution X-ray crystal structures of CtdE with the substrate and cofactor, together with site-directed mutagenesis and computational studies, illustrate the catalytic mechanisms for the possible β-face epoxidation followed by a regioselective collapse of the epoxide intermediate, which triggers semipinacol rearrangement to form the 3S-spirooxindole. Comparing CtdE with PhqK, which catalyzes the formation of the 3R-spirooxindole, we reveal an evolutionary branch of CtdE in specific 3S spirocyclization. Our study provides deeper insights into the stereoselective catalytic machinery, which is important for the biocatalysis design to synthesize spirooxindole pharmaceuticals.
Collapse
Affiliation(s)
- Zhiwen Liu
- Department of Chemical and Biomolecular Engineering, Rice University, Houston, TX, USA
| | - Fanglong Zhao
- Department of Chemical and Biomolecular Engineering, Rice University, Houston, TX, USA
| | - Boyang Zhao
- Department of Molecular Virology and Microbiology, Baylor College of Medicine, Houston, TX, USA
| | - Jie Yang
- Department of Chemical and Biomolecular Engineering, Rice University, Houston, TX, USA
| | | | - Banumathi Sankaran
- Department of Molecular Biophysics and Integrated Bioimaging, Berkeley Center for Structural Biology, Lawrence Berkeley National Laboratory, Berkeley, CA, USA
| | - B V Venkataram Prasad
- Department of Molecular Virology and Microbiology, Baylor College of Medicine, Houston, TX, USA
- Verna and Marrs McLean Department of Biochemistry and Molecular Biology, Baylor College of Medicine, Houston, TX, USA
| | - Biki Bapi Kundu
- PhD Program in Systems, Synthetic, and Physical Biology, Rice University, Houston, TX, USA
| | - George N Phillips
- Department of Biosciences, Rice University, Houston, TX, USA
- Department of Chemistry, Rice University, Houston, TX, USA
| | - Yang Gao
- Department of Biosciences, Rice University, Houston, TX, USA
| | - Liya Hu
- Verna and Marrs McLean Department of Biochemistry and Molecular Biology, Baylor College of Medicine, Houston, TX, USA
| | - Tong Zhu
- Shanghai Engineering Research Center of Molecular Therapeutics & New Drug Development, School of Chemistry and Molecular Engineering, East China Normal University, Shanghai, China.
| | - Xue Gao
- Department of Chemical and Biomolecular Engineering, Rice University, Houston, TX, USA.
- Department of Chemistry, Rice University, Houston, TX, USA.
- Department of Bioengineering, Rice University, Houston, TX, USA.
| |
Collapse
|
9
|
Westphal AH, Tischler D, van Berkel WJH. Natural diversity of FAD-dependent 4-hydroxybenzoate hydroxylases. Arch Biochem Biophys 2021; 702:108820. [PMID: 33684360 DOI: 10.1016/j.abb.2021.108820] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2020] [Revised: 02/19/2021] [Accepted: 02/21/2021] [Indexed: 01/05/2023]
Abstract
4-Hydroxybenzoate 3-hydroxylase (PHBH) is the most extensively studied group A flavoprotein monooxygenase (FPMO). PHBH is almost exclusively found in prokaryotes, where its induction, usually as a consequence of lignin degradation, results in the regioselective formation of protocatechuate, one of the central intermediates in the global carbon cycle. In this contribution we introduce several less known FAD-dependent 4-hydroxybenzoate hydroxylases. Phylogenetic analysis showed that the enzymes discussed here reside in distinct clades of the group A FPMO family, indicating their separate divergence from a common ancestor. Protein homology modelling revealed that the fungal 4-hydroxybenzoate 3-hydroxylase PhhA is structurally related to phenol hydroxylase (PHHY) and 3-hydroxybenzoate 4-hydroxylase (3HB4H). 4-Hydroxybenzoate 1-hydroxylase (4HB1H) from yeast catalyzes an oxidative decarboxylation reaction and is structurally similar to 3-hydroxybenzoate 6-hydroxylase (3HB6H), salicylate hydroxylase (SALH) and 6-hydroxynicotinate 3-monooxygenase (6HNMO). Genome mining suggests that the 4HB1H activity is widespread in the fungal kingdom and might be responsible for the oxidative decarboxylation of vanillate, an import intermediate in lignin degradation. 4-Hydroxybenzoyl-CoA 1-hydroxylase (PhgA) catalyzes an intramolecular migration reaction (NIH shift) during the three-step conversion of 4-hydroxybenzoate to gentisate in certain Bacillus species. PhgA is phylogenetically related to 4-hydroxyphenylacetate 1-hydroxylase (4HPA1H). In summary, this paper shines light on the natural diversity of group A FPMOs that are involved in the aerobic microbial catabolism of 4-hydroxybenzoate.
Collapse
Affiliation(s)
- Adrie H Westphal
- Laboratory of Biochemistry, Wageningen University & Research, Wageningen, the Netherlands.
| | - Dirk Tischler
- Microbial Biotechnology, Faculty of Biology and Biotechnology, Ruhr-Universität Bochum, Germany.
| | - Willem J H van Berkel
- Laboratory of Food Chemistry, Wageningen University & Research, Wageningen, the Netherlands.
| |
Collapse
|
10
|
Paul CE, Eggerichs D, Westphal AH, Tischler D, van Berkel WJH. Flavoprotein monooxygenases: Versatile biocatalysts. Biotechnol Adv 2021; 51:107712. [PMID: 33588053 DOI: 10.1016/j.biotechadv.2021.107712] [Citation(s) in RCA: 68] [Impact Index Per Article: 22.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2020] [Revised: 01/27/2021] [Accepted: 02/06/2021] [Indexed: 12/13/2022]
Abstract
Flavoprotein monooxygenases (FPMOs) are single- or two-component enzymes that catalyze a diverse set of chemo-, regio- and enantioselective oxyfunctionalization reactions. In this review, we describe how FPMOs have evolved from model enzymes in mechanistic flavoprotein research to biotechnologically relevant catalysts that can be applied for the sustainable production of valuable chemicals. After a historical account of the development of the FPMO field, we explain the FPMO classification system, which is primarily based on protein structural properties and electron donor specificities. We then summarize the most appealing reactions catalyzed by each group with a focus on the different types of oxygenation chemistries. Wherever relevant, we report engineering strategies that have been used to improve the robustness and applicability of FPMOs.
Collapse
Affiliation(s)
- Caroline E Paul
- Biocatalysis, Department of Biotechnology, Delft University of Technology, Van der Maasweg 9, 2629 HZ Delft, The Netherlands
| | - Daniel Eggerichs
- Microbial Biotechnology, Faculty of Biology and Biotechnology, Ruhr-Universität Bochum, Universitätsstrasse 150, 44780 Bochum, Germany
| | - Adrie H Westphal
- Laboratory of Biochemistry, Wageningen University, Stippeneng 4, 6708 WE Wageningen, The Netherlands
| | - Dirk Tischler
- Microbial Biotechnology, Faculty of Biology and Biotechnology, Ruhr-Universität Bochum, Universitätsstrasse 150, 44780 Bochum, Germany
| | - Willem J H van Berkel
- Laboratory of Food Chemistry, Wageningen University, Bornse Weilanden 9, 6708 WG Wageningen, The Netherlands.
| |
Collapse
|
11
|
Abstract
Many flavin-dependent phenolic hydroxylases (monooxygenases) have been extensively investigated. Their crystal structures and reaction mechanisms are well understood. These enzymes belong to groups A and D of the flavin-dependent monooxygenases and can be classified as single-component and two-component flavin-dependent monooxygenases. The insertion of molecular oxygen into the substrates catalyzed by these enzymes is beneficial for modifying the biological properties of phenolic compounds and their derivatives. This chapter provides an in-depth discussion of the structural features of single-component and two-component flavin-dependent phenolic hydroxylases. The reaction mechanisms of selected enzymes, including 3-hydroxy-benzoate 4-hydroxylase (PHBH) and 3-hydroxy-benzoate 6-hydroxylase as representatives of single-component enzymes and 3-hydroxyphenylacetate 4-hydroxylase (HPAH) as a representative of two-component enzymes, are discussed in detail. This chapter comprises the following four main parts: general reaction, structures, reaction mechanisms, and enzyme engineering for biocatalytic applications. Enzymes belonging to the same group catalyze similar reactions but have different unique structural features to control their reactivity to substrates and the formation and stabilization of C4a-hydroperoxyflavin. Protein engineering has been employed to improve the ability to use these enzymes to synthesize valuable compounds. A thorough understanding of the structural and mechanistic features controlling enzyme reactivity is useful for enzyme redesign and enzyme engineering for future biocatalytic applications.
Collapse
Affiliation(s)
- Pirom Chenprakhon
- Institute for Innovative Learning, Mahidol University, Nakhon Pathom, Thailand.
| | - Panu Pimviriyakul
- Department of Biochemistry, Faculty of Science, Kasetsart University, Chatuchak, Bangkok, Thailand; Department of Biotechnology, Faculty of Engineering and Industrial Technology, Silpakorn University, Nakhon Pathom, Thailand
| | - Chanakan Tongsook
- Department of Chemistry, Faculty of Science, Silpakorn University, Nakhon Pathom, Thailand
| | - Pimchai Chaiyen
- School of Biomolecular Science and Engineering, Vidyasirimedhi Institute of Science and Technology (VISTEC), Wangchan Valley, Rayong, Thailand
| |
Collapse
|
12
|
Abstract
Flavoenzymes are broadly employed as biocatalysts for a large variety of reactions, owing to the chemical versatility of the flavin cofactor. Oxidases set aside, many flavoenzymes require a source of electrons in form of the biological reductant nicotinamide NAD(P)H in order to initiate catalysis via the reduced flavin. Chemists can take advantage of the reactivity of reduced flavins with oxygen to carry out monooxygenation reactions, while the reduced flavin can also be used for formal hydrogenation reactions. The main advantage of these reactions compared to chemical approaches is the frequent regio-, chemo- and stereo-selectivity of the biocatalysts, which allows the synthesis of chiral molecules in optically active form. This chapter provides an overview of the variety of biocatalytic processes that have been developed with flavoenzymes, with a particular focus on nicotinamide-dependent enzymes. The diversity of molecules obtained is highlighted and in several cases, strategies that allow control of the stereochemical outcome of the reactions are reviewed.
Collapse
Affiliation(s)
- Mélanie Hall
- Department of Chemistry, University of Graz, Graz, Austria.
| |
Collapse
|
13
|
Manenda MS, Picard MÈ, Zhang L, Cyr N, Zhu X, Barma J, Pascal JM, Couture M, Zhang C, Shi R. Structural analyses of the Group A flavin-dependent monooxygenase PieE reveal a sliding FAD cofactor conformation bridging OUT and IN conformations. J Biol Chem 2020; 295:4709-4722. [PMID: 32111738 DOI: 10.1074/jbc.ra119.011212] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2019] [Revised: 02/26/2020] [Indexed: 02/02/2023] Open
Abstract
Group A flavin-dependent monooxygenases catalyze the cleavage of the oxygen-oxygen bond of dioxygen, followed by the incorporation of one oxygen atom into the substrate molecule with the aid of NADPH and FAD. These flavoenzymes play an important role in many biological processes, and their most distinct structural feature is the choreographed motions of flavin, which typically adopts two distinct conformations (OUT and IN) to fulfill its function. Notably, these enzymes seem to have evolved a delicate control system to avoid the futile cycle of NADPH oxidation and FAD reduction in the absence of substrate, but the molecular basis of this system remains elusive. Using protein crystallography, size-exclusion chromatography coupled to multi-angle light scattering (SEC-MALS), and small-angle X-ray scattering (SEC-SAXS) and activity assay, we report here a structural and biochemical characterization of PieE, a member of the Group A flavin-dependent monooxygenases involved in the biosynthesis of the antibiotic piericidin A1. This analysis revealed that PieE forms a unique hexamer. Moreover, we found, to the best of our knowledge for the first time, that in addition to the classical OUT and IN conformations, FAD possesses a "sliding" conformation that exists in between the OUT and IN conformations. This observation sheds light on the underlying mechanism of how the signal of substrate binding is transmitted to the FAD-binding site to efficiently initiate NADPH binding and FAD reduction. Our findings bridge a gap currently missing in the orchestrated order of chemical events catalyzed by this important class of enzymes.
Collapse
Affiliation(s)
- Mahder S Manenda
- Département de Biochimie, de Microbiologie, et de Bio-informatique, PROTEO, Université Laval, Québec G1V 0A6, Canada.,Institut de Biologie Intégrative et des Systèmes (IBIS), Université Laval, Québec G1V 0A6, Canada
| | - Marie-Ève Picard
- Département de Biochimie, de Microbiologie, et de Bio-informatique, PROTEO, Université Laval, Québec G1V 0A6, Canada.,Institut de Biologie Intégrative et des Systèmes (IBIS), Université Laval, Québec G1V 0A6, Canada
| | - Liping Zhang
- CAS Key Laboratory of Tropical Marine Bio-resources and Ecology, RNAM Center for Marine Microbiology, Guangdong Key Laboratory of Marine Materia Medica, South China Sea Institute of Oceanology, Chinese Academy of Sciences, 164 West Xingang Road, Guangzhou 510301, China
| | - Normand Cyr
- Département de biochimie et médecine moléculaire, Université de Montréal, Montréal, Québec H3T 1J4, Canada
| | - Xiaojun Zhu
- Département de Biochimie, de Microbiologie, et de Bio-informatique, PROTEO, Université Laval, Québec G1V 0A6, Canada.,Institut de Biologie Intégrative et des Systèmes (IBIS), Université Laval, Québec G1V 0A6, Canada
| | - Julie Barma
- Département de Biochimie, de Microbiologie, et de Bio-informatique, PROTEO, Université Laval, Québec G1V 0A6, Canada.,Institut de Biologie Intégrative et des Systèmes (IBIS), Université Laval, Québec G1V 0A6, Canada
| | - John M Pascal
- Département de biochimie et médecine moléculaire, Université de Montréal, Montréal, Québec H3T 1J4, Canada
| | - Manon Couture
- Département de Biochimie, de Microbiologie, et de Bio-informatique, PROTEO, Université Laval, Québec G1V 0A6, Canada.,Institut de Biologie Intégrative et des Systèmes (IBIS), Université Laval, Québec G1V 0A6, Canada
| | - Changsheng Zhang
- CAS Key Laboratory of Tropical Marine Bio-resources and Ecology, RNAM Center for Marine Microbiology, Guangdong Key Laboratory of Marine Materia Medica, South China Sea Institute of Oceanology, Chinese Academy of Sciences, 164 West Xingang Road, Guangzhou 510301, China
| | - Rong Shi
- Département de Biochimie, de Microbiologie, et de Bio-informatique, PROTEO, Université Laval, Québec G1V 0A6, Canada .,Institut de Biologie Intégrative et des Systèmes (IBIS), Université Laval, Québec G1V 0A6, Canada
| |
Collapse
|
14
|
Pitsawong W, Chenprakhon P, Dhammaraj T, Medhanavyn D, Sucharitakul J, Tongsook C, van Berkel WJH, Chaiyen P, Miller AF. Tuning of p Ka values activates substrates in flavin-dependent aromatic hydroxylases. J Biol Chem 2020; 295:3965-3981. [PMID: 32014994 DOI: 10.1074/jbc.ra119.011884] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2019] [Revised: 01/29/2020] [Indexed: 12/31/2022] Open
Abstract
Hydroxylation of substituted phenols by flavin-dependent monooxygenases is the first step of their biotransformation in various microorganisms. The reaction is thought to proceed via electrophilic aromatic substitution, catalyzed by enzymatic deprotonation of substrate, in single-component hydroxylases that use flavin as a cofactor (group A). However, two-component hydroxylases (group D), which use reduced flavin as a co-substrate, are less amenable to spectroscopic investigation. Herein, we employed 19F NMR in conjunction with fluorinated substrate analogs to directly measure pKa values and to monitor protein events in hydroxylase active sites. We found that the single-component monooxygenase 3-hydroxybenzoate 6-hydroxylase (3HB6H) depresses the pKa of the bound substrate analog 4-fluoro-3-hydroxybenzoate (4F3HB) by 1.6 pH units, consistent with previously proposed mechanisms. 19F NMR was applied anaerobically to the two-component monooxygenase 4-hydroxyphenylacetate 3-hydroxylase (HPAH), revealing depression of the pKa of 3-fluoro-4-hydroxyphenylacetate by 2.5 pH units upon binding to the C2 component of HPAH. 19F NMR also revealed a pKa of 8.7 ± 0.05 that we attributed to an active-site residue involved in deprotonating bound substrate, and assigned to His-120 based on studies of protein variants. Thus, in both types of hydroxylases, we confirmed that binding favors the phenolate form of substrate. The 9 and 14 kJ/mol magnitudes of the effects for 3HB6H and HPAH-C2, respectively, are consistent with pKa tuning by one or more H-bonding interactions. Our implementation of 19F NMR in anaerobic samples is applicable to other two-component flavin-dependent hydroxylases and promises to expand our understanding of their catalytic mechanisms.
Collapse
Affiliation(s)
- Warintra Pitsawong
- Department of Chemistry, University of Kentucky, Lexington, Kentucky 40506-0055
| | - Pirom Chenprakhon
- Institute for Innovative Learning, Mahidol University, Nakhon Pathom 73170, Thailand
| | - Taweesak Dhammaraj
- Faculty of Pharmacy, Mahasarakham University, Maha Sarakham 44150, Thailand
| | - Dheeradhach Medhanavyn
- Department of Biochemistry and Center for Excellence in Protein and Enzyme Technology, Faculty of Science, Mahidol University, Bangkok 10400, Thailand
| | - Jeerus Sucharitakul
- Department of Biochemistry, Faculty of Dentistry, Chulalongkorn University, Bangkok 10300, Thailand
| | - Chanakan Tongsook
- Department of Chemistry, Faculty of Science, Silpakorn University, Nakhon Pathom 73000, Thailand
| | - Willem J H van Berkel
- Laboratory of Food Chemistry, Wageningen University and Research, Bornse Weilanden 9, 6708 WG, Wageningen, The Netherlands
| | - Pimchai Chaiyen
- School of Biomolecular Science and Engineering, Vidyasirimedhi Institute of Science and Technology, Wangchan Valley, 555 Moo 1 Payupnai, Wangchan, Rayong 21210, Thailand
| | - Anne-Frances Miller
- Department of Chemistry, University of Kentucky, Lexington, Kentucky 40506-0055
| |
Collapse
|
15
|
Catalytic mechanism for the conversion of salicylate into catechol by the flavin-dependent monooxygenase salicylate hydroxylase. Int J Biol Macromol 2019; 129:588-600. [DOI: 10.1016/j.ijbiomac.2019.01.135] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2018] [Revised: 01/24/2019] [Accepted: 01/24/2019] [Indexed: 11/17/2022]
|
16
|
Braesel J, Lee JH, Arnould B, Murphy BT, Eustáquio AS. Diazaquinomycin Biosynthetic Gene Clusters from Marine and Freshwater Actinomycetes. JOURNAL OF NATURAL PRODUCTS 2019; 82:937-946. [PMID: 30896942 PMCID: PMC6902439 DOI: 10.1021/acs.jnatprod.8b01028] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/17/2023]
Abstract
Tuberculosis is an infectious disease of global concern. Members of the diazaquinomycin (DAQ) class of natural products have shown potent and selective activity against drug-resistant Mycobacterium tuberculosis. However, poor solubility has prevented further development of this compound class. Understanding DAQ biosynthesis may provide a viable route for the generation of derivatives with improved properties. We have sequenced the genomes of two actinomycete bacteria that produce distinct DAQ derivatives. While software tools for automated biosynthetic gene cluster (BGC) prediction failed to detect DAQ BGCs, comparative genomics using MAUVE alignment led to the identification of putative BGCs in the marine Streptomyces sp. F001 and in the freshwater Micromonospora sp. B006. Deletion of the identified daq BGC in strain B006 using CRISPR-Cas9 genome editing abolished DAQ production, providing experimental evidence for BGC assignment. A complete model for DAQ biosynthesis is proposed based on the genes identified. Insufficient knowledge of natural product biosynthesis is one of the major challenges of productive genome mining approaches. The results reported here fill a gap in knowledge regarding the genetic basis for the biosynthesis of DAQ antibiotics. Moreover, identification of the daq BGC shall enable future generations of improved derivatives using biosynthetic methods.
Collapse
Affiliation(s)
- Jana Braesel
- Department of Medicinal Chemistry and Pharmacognosy and Center for Biomolecular Sciences, College of Pharmacy, University of Illinois at Chicago, Chicago, IL 60607, USA
| | - Jung-Ho Lee
- Department of Medicinal Chemistry and Pharmacognosy and Center for Biomolecular Sciences, College of Pharmacy, University of Illinois at Chicago, Chicago, IL 60607, USA
| | - Benoit Arnould
- Department of Medicinal Chemistry and Pharmacognosy and Center for Biomolecular Sciences, College of Pharmacy, University of Illinois at Chicago, Chicago, IL 60607, USA
| | - Brian T. Murphy
- Department of Medicinal Chemistry and Pharmacognosy and Center for Biomolecular Sciences, College of Pharmacy, University of Illinois at Chicago, Chicago, IL 60607, USA
| | - Alessandra S. Eustáquio
- Department of Medicinal Chemistry and Pharmacognosy and Center for Biomolecular Sciences, College of Pharmacy, University of Illinois at Chicago, Chicago, IL 60607, USA
| |
Collapse
|
17
|
Tischler D, van Berkel WJH, Fraaije MW. Editorial: Actinobacteria, a Source of Biocatalytic Tools. Front Microbiol 2019; 10:800. [PMID: 31040839 PMCID: PMC6477052 DOI: 10.3389/fmicb.2019.00800] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2019] [Accepted: 03/28/2019] [Indexed: 11/28/2022] Open
Affiliation(s)
- Dirk Tischler
- Microbial Biotechnology, Biology and Biotechnology, Ruhr University Bochum, Bochum, Germany
| | - Willem J H van Berkel
- Laboratory of Biochemistry, Wageningen University & Research, Wageningen, Netherlands
| | - Marco W Fraaije
- Molecular Enzymology, University of Groningen, Groningen, Netherlands
| |
Collapse
|
18
|
Rodríguez Benítez A, Tweedy SE, Baker Dockrey SA, Lukowski AL, Wymore T, Khare D, Brooks CL, Palfey BA, Smith JL, Narayan ARH. Structural basis for selectivity in flavin-dependent monooxygenase-catalyzed oxidative dearomatization. ACS Catal 2019; 9:3633-3640. [PMID: 31346489 DOI: 10.1021/acscatal.8b04575] [Citation(s) in RCA: 28] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Abstract
Biocatalytic reactions embody many features of ideal chemical transformations, including the potential for impeccable selectivity, high catalytic efficiency, mild reaction conditions and the use of environmentally benign reagents. These advantages have created a demand for biocatalysts that expand the portfolio of complexity-generating reactions available to synthetic chemists. However, the tradeoff that often exists between the substrate scope of a biocatalyst and its selectivity limits the application of enzymes in synthesis. We recently demonstrated that a flavin-dependent monooxygenase, TropB, maintains high levels of site- and stereoselectivity across a range of structurally diverse substrates. Herein, we disclose the structural basis for substrate binding in TropB, which performs a synthetically challenging asymmetric oxidative dearomatization reaction with exquisite site- and stereoselectivity across a range of phenol substrates, providing a foundation for future protein engineering and reaction development efforts. Our hypothesis for substrate binding is informed by a crystal structure of TropB and molecular dynamics simulations with the corresponding computational TropB model and is supported by experimental data. In contrast to canonical class A FAD-dependent monooxygenases in which substrates bind in a protonated form, our data indicate that the phenolate form of the substrate binds in the active site. Furthermore, the substrate position is controlled through twopoint binding of the phenolate oxygen to Arg206 and Tyr239, which are shown to have distinct and essential roles in catalysis. Arg206 is involved in the reduction of the flavin cofactor, suggesting a role in flavin dynamics. Further, QM/MM simulations reveal the interactions that govern the facial selectivity that leads to a highly enantioselective transformation. Thus, the structural origins of the high levels of site-and stereoselectivity observed in reactions of TropB across a range of substrates are elucidated, providing a foundation for future protein engineering and reaction development efforts.
Collapse
|
19
|
Nakamoto KD, Perkins SW, Campbell RG, Bauerle MR, Gerwig TJ, Gerislioglu S, Wesdemiotis C, Anderson MA, Hicks KA, Snider MJ. Mechanism of 6-Hydroxynicotinate 3-Monooxygenase, a Flavin-Dependent Decarboxylative Hydroxylase Involved in Bacterial Nicotinic Acid Degradation. Biochemistry 2019; 58:1751-1763. [PMID: 30810301 DOI: 10.1021/acs.biochem.8b00969] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
6-Hydroxynicotinate 3-monooxygenase (NicC) is a Group A FAD-dependent monooxygenase that catalyzes the decarboxylative hydroxylation of 6-hydroxynicotinic acid (6-HNA) to 2,5-dihydroxypyridine (2,5-DHP) with concomitant oxidation of NADH in nicotinic acid degradation by aerobic bacteria. Two mechanisms for the decarboxylative hydroxylation half-reaction have been proposed [Hicks, K., et al. (2016) Biochemistry 55, 3432-3446]. Results with Bordetella bronchiseptica RB50 NicC here show that a homocyclic analogue of 6-HNA, 4-hydroxybenzoic acid (4-HBA), is decarboxylated and hydroxylated by NicC with a 420-fold lower catalytic efficiency than is 6-HNA. The 13( V/ K), measured with wild-type NicC by isotope ratio mass spectrometry following the natural abundance of 13C in the CO2 product, is inverse for both 6-HNA (0.9989 ± 0.0002) and 4-HBA (0.9942 ± 0.0004) and becomes negligible (0.9999 ± 0.0004) for 5-chloro-6-HNA, an analogue that is 10-fold more catalytically efficient than 6-HNA. Covalently bound 6-HNA complexes of NicC are not observed by mass spectrometry. Comparative steady-state kinetic and Kd6HNA analyses of active site NicC variants (C202A, H211A, H302A, H47E, Y215F, and Y225F) identify Tyr215 and His47 as critical determinants both of 6-HNA binding ( KdY215F/ KdWT > 240; KdH47E/ KdWT > 350) and in coupling rates of 2,5-DHP and NAD+ product formation ([2,5-DHP]/[NAD+] = 1.00 (WT), 0.005 (Y215F), and 0.07 (H47E)]. Results of these functional analyses are in accord with an electrophilic aromatic substitution reaction mechanism in which His47-Tyr215 may serve as the general base to catalyze substrate hydroxylation and refine the structural model for substrate binding by NicC.
Collapse
Affiliation(s)
- Kent D Nakamoto
- Department of Chemistry , The College of Wooster , Wooster , Ohio 44691 , United States
| | - Scott W Perkins
- Department of Chemistry , The College of Wooster , Wooster , Ohio 44691 , United States
| | - Ryan G Campbell
- Department of Chemistry , The College of Wooster , Wooster , Ohio 44691 , United States
| | - Matthew R Bauerle
- Department of Chemistry , The College of Wooster , Wooster , Ohio 44691 , United States
| | - Tyler J Gerwig
- Department of Chemistry , The College of Wooster , Wooster , Ohio 44691 , United States
| | - Selim Gerislioglu
- Department of Chemistry , University of Akron , Akron , Ohio 44325 , United States
| | - Chrys Wesdemiotis
- Department of Chemistry , University of Akron , Akron , Ohio 44325 , United States
| | - Mark A Anderson
- Institute for Enzyme Research, Department of Biochemistry , University of Wisconsin , Madison , Wisconsin 53726 , United States
| | - Katherine A Hicks
- Department of Chemistry , The State University of New York College at Cortland , Cortland , New York 13045 , United States
| | - Mark J Snider
- Department of Chemistry , The College of Wooster , Wooster , Ohio 44691 , United States
| |
Collapse
|
20
|
Waldron EJ, Snyder D, Fernandez NL, Sileo E, Inoyama D, Freundlich JS, Waters CM, Cooper VS, Neiditch MB. Structural basis of DSF recognition by its receptor RpfR and its regulatory interaction with the DSF synthase RpfF. PLoS Biol 2019; 17:e3000123. [PMID: 30716063 PMCID: PMC6361424 DOI: 10.1371/journal.pbio.3000123] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2018] [Accepted: 01/10/2019] [Indexed: 01/07/2023] Open
Abstract
The diffusible signal factors (DSFs) are a family of quorum-sensing autoinducers (AIs) produced and detected by numerous gram-negative bacteria. The DSF family AIs are fatty acids, differing in their acyl chain length, branching, and substitution but having in common a cis-2 double bond that is required for their activity. In both human and plant pathogens, DSFs regulate diverse phenotypes, including virulence factor expression, antibiotic resistance, and biofilm dispersal. Despite their widespread relevance to both human health and agriculture, the molecular basis of DSF recognition by their cellular receptors remained a mystery. Here, we report the first structure-function studies of the DSF receptor regulation of pathogenicity factor R (RpfR). We present the X-ray crystal structure of the RpfR DSF-binding domain in complex with the Burkholderia DSF (BDSF), which to our knowledge is the first structure of a DSF receptor in complex with its AI. To begin to understand the mechanistic role of the BDSF-RpfR contacts observed in the biologically important complex, we have also determined the X-ray crystal structure of the RpfR DSF-binding domain in complex with the inactive, saturated isomer of BDSF, dodecanoic acid (C12:0). In addition to these ligand-receptor complex structures, we report the discovery of a previously overlooked RpfR domain and show that it binds to and negatively regulates the DSF synthase regulation of pathogenicity factor F (RpfF). We have named this RpfR region the RpfF interaction (FI) domain, and we have determined its X-ray crystal structure alone and in complex with RpfF. These X-ray crystal structures, together with extensive complementary in vivo and in vitro functional studies, reveal the molecular basis of DSF recognition and the importance of the cis-2 double bond to DSF function. Finally, we show that throughout cellular growth, the production of BDSF by RpfF is post-translationally controlled by the RpfR N-terminal FI domain, affecting the cellular concentration of the bacterial second messenger bis-(3'-5')-cyclic dimeric guanosine monophosphate (c-di-GMP). Thus, in addition to describing the molecular basis for the binding and specificity of a DSF for its receptor, we describe a receptor-synthase interaction regulating bacterial quorum-sensing signaling and second messenger signal transduction.
Collapse
Affiliation(s)
- Evan J. Waldron
- Department of Microbiology, Biochemistry, and Molecular Genetics, New Jersey Medical School, Rutgers, State University of New Jersey, Newark, New Jersey, United States of America
| | - Daniel Snyder
- Department of Microbiology and Molecular Genetics, and Center for Evolutionary Biology and Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania, United States of America
| | - Nicolas L. Fernandez
- Department of Microbiology and Molecular Genetics and the BEACON Center for the Study of Evolution in Action, Michigan State University, East Lansing, Michigan, United States of America
| | - Emily Sileo
- Department of Microbiology and Molecular Genetics, and Center for Evolutionary Biology and Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania, United States of America
| | - Daigo Inoyama
- Department of Pharmacology, Physiology, and Neuroscience, New Jersey Medical School, Rutgers, State University of New Jersey, Newark, New Jersey, United States of America
| | - Joel S. Freundlich
- Department of Pharmacology, Physiology, and Neuroscience, New Jersey Medical School, Rutgers, State University of New Jersey, Newark, New Jersey, United States of America
| | - Christopher M. Waters
- Department of Microbiology and Molecular Genetics and the BEACON Center for the Study of Evolution in Action, Michigan State University, East Lansing, Michigan, United States of America
| | - Vaughn S. Cooper
- Department of Microbiology and Molecular Genetics, and Center for Evolutionary Biology and Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania, United States of America
| | - Matthew B. Neiditch
- Department of Microbiology, Biochemistry, and Molecular Genetics, New Jersey Medical School, Rutgers, State University of New Jersey, Newark, New Jersey, United States of America
- * E-mail:
| |
Collapse
|
21
|
Huang Y, Duan Y, Zhang Y, Fan P, Li Z, Liu W, Cui Z. Crystal structure of hydroxyquinol 1,2-dioxygenase PnpC from Pseudomonas putida DLL-E4 and its role of N-terminal domain for catalysis. Biochem Biophys Res Commun 2018; 507:267-273. [PMID: 30446218 DOI: 10.1016/j.bbrc.2018.11.020] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2018] [Accepted: 11/04/2018] [Indexed: 11/29/2022]
Abstract
Hydroxyquinol 1,2-dioxygenase is a key enzyme in the hydroxyquinol pathway of p-nitrophenol (PNP) degradation, and catalyzes the ring cleavage of benzenetriol to maleylacetate. Here, we report the first structure of a hydroxyquinol 1,2-dioxygenase from the Gram-negative bacterium Pseudomonas putida DLL-E4 (PnpC) at the resolution of 2.1 Å. The tertiary structure of PnpC resembles that of the homologous intradiol dioxygenases. The catalytic Fe(III) is pentacoordinated by the conserved Tyr160, Tyr194, His218 and His220, the citrate anion and one water molecule. Among the residues expected to interact with the substrate, structural comparison with the (chloro)catechol dioxygenases suggested that Asp80, Thr81 and Val248 are responsible for the substrate specificity. Moreover, truncation of the N-terminal α-helix of PnpC suggested the N-terminal domain is required for its soluble expression and enzyme catalysis. Our results might provide insights in the substrate recognition and rational design of this enzyme class to be used in bioremediation.
Collapse
Affiliation(s)
- Yan Huang
- Key Laboratory of Agricultural Environmental Microbiology, Ministry of Agriculture, College of Life Sciences, Nanjing Agricultural University, Nanjing, China
| | - Yajuan Duan
- Key Laboratory of Agricultural Environmental Microbiology, Ministry of Agriculture, College of Life Sciences, Nanjing Agricultural University, Nanjing, China
| | - Yajuan Zhang
- Key Laboratory of Agricultural Environmental Microbiology, Ministry of Agriculture, College of Life Sciences, Nanjing Agricultural University, Nanjing, China
| | - Panpan Fan
- Key Laboratory of Agricultural Environmental Microbiology, Ministry of Agriculture, College of Life Sciences, Nanjing Agricultural University, Nanjing, China
| | - Zhoukun Li
- Key Laboratory of Agricultural Environmental Microbiology, Ministry of Agriculture, College of Life Sciences, Nanjing Agricultural University, Nanjing, China
| | - Weidong Liu
- Industrial Enzymes National Engineering Laboratory, Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin, 300308, China
| | - Zhongli Cui
- Key Laboratory of Agricultural Environmental Microbiology, Ministry of Agriculture, College of Life Sciences, Nanjing Agricultural University, Nanjing, China.
| |
Collapse
|
22
|
Chen Q, Huang Y, Duan Y, Li Z, Cui Z, Liu W. Crystal structure of p-nitrophenol 4-monooxygenase PnpA from Pseudomonas putida DLL-E4: The key enzyme involved in p-nitrophenol degradation. Biochem Biophys Res Commun 2018; 504:715-720. [PMID: 30217456 DOI: 10.1016/j.bbrc.2018.09.040] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2018] [Accepted: 09/07/2018] [Indexed: 02/07/2023]
Abstract
p-Nitrophenol 4-monooxygenase PnpA, the key enzyme in the hydroquinone pathway of p-nitrophenol (PNP) degradation, catalyzes the monooxygenase reaction of PNP to p-benzoquinone in the presence of FAD and NADH. Here, we determined the first crystal structure of PnpA from Pseudomonas putida DLL-E4 in its apo and FAD-complex forms to a resolution of 2.04 Å and 2.48 Å, respectively. The PnpA structure shares a common fold with hydroxybenzoate hydroxylases, despite a low amino sequence identity of 14-18%, confirming it to be a member of the Class A flavoprotein monooxygenases. However, substrate docking studies of PnpA indicated that the residues stabilizing the substrate in an orientation suitable for catalysis are not observed in other homologous hydroxybenzoate hydroxylases, suggesting PnpA employs a unique catalytic mechanism. This work expands our understanding on the reaction mode for this enzyme class.
Collapse
Affiliation(s)
- Qiongzhen Chen
- Key Laboratory of Agricultural Environmental Microbiology, Ministry of Agriculture, College of Life Sciences, Nanjing Agricultural University, Nanjing, China
| | - Yan Huang
- Key Laboratory of Agricultural Environmental Microbiology, Ministry of Agriculture, College of Life Sciences, Nanjing Agricultural University, Nanjing, China
| | - Yajuan Duan
- Key Laboratory of Agricultural Environmental Microbiology, Ministry of Agriculture, College of Life Sciences, Nanjing Agricultural University, Nanjing, China
| | - Zhoukun Li
- Key Laboratory of Agricultural Environmental Microbiology, Ministry of Agriculture, College of Life Sciences, Nanjing Agricultural University, Nanjing, China
| | - Zhongli Cui
- Key Laboratory of Agricultural Environmental Microbiology, Ministry of Agriculture, College of Life Sciences, Nanjing Agricultural University, Nanjing, China.
| | - Weidong Liu
- Industrial Enzymes National Engineering Laboratory, Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin, 300308, China.
| |
Collapse
|
23
|
Dong J, Fernández‐Fueyo E, Hollmann F, Paul CE, Pesic M, Schmidt S, Wang Y, Younes S, Zhang W. Biocatalytic Oxidation Reactions: A Chemist's Perspective. Angew Chem Int Ed Engl 2018; 57:9238-9261. [PMID: 29573076 PMCID: PMC6099261 DOI: 10.1002/anie.201800343] [Citation(s) in RCA: 276] [Impact Index Per Article: 46.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2018] [Indexed: 01/25/2023]
Abstract
Oxidation chemistry using enzymes is approaching maturity and practical applicability in organic synthesis. Oxidoreductases (enzymes catalysing redox reactions) enable chemists to perform highly selective and efficient transformations ranging from simple alcohol oxidations to stereoselective halogenations of non-activated C-H bonds. For many of these reactions, no "classical" chemical counterpart is known. Hence oxidoreductases open up shorter synthesis routes based on a more direct access to the target products. The generally very mild reaction conditions may also reduce the environmental impact of biocatalytic reactions compared to classical counterparts. In this Review, we critically summarise the most important recent developments in the field of biocatalytic oxidation chemistry and identify the most pressing bottlenecks as well as promising solutions.
Collapse
Affiliation(s)
- JiaJia Dong
- Department of BiotechnologyDelft University of Technologyvan der Maasweg 92629HZDelftThe Netherlands
| | - Elena Fernández‐Fueyo
- Department of BiotechnologyDelft University of Technologyvan der Maasweg 92629HZDelftThe Netherlands
| | - Frank Hollmann
- Department of BiotechnologyDelft University of Technologyvan der Maasweg 92629HZDelftThe Netherlands
| | - Caroline E. Paul
- Department of BiotechnologyDelft University of Technologyvan der Maasweg 92629HZDelftThe Netherlands
| | - Milja Pesic
- Department of BiotechnologyDelft University of Technologyvan der Maasweg 92629HZDelftThe Netherlands
| | - Sandy Schmidt
- Department of BiotechnologyDelft University of Technologyvan der Maasweg 92629HZDelftThe Netherlands
| | - Yonghua Wang
- School of Food Science and EngineeringSouth China University of TechnologyGuangzhou510640P. R. China
| | - Sabry Younes
- Department of BiotechnologyDelft University of Technologyvan der Maasweg 92629HZDelftThe Netherlands
| | - Wuyuan Zhang
- Department of BiotechnologyDelft University of Technologyvan der Maasweg 92629HZDelftThe Netherlands
| |
Collapse
|
24
|
Chen X, Tang H, Liu Y, Xu P, Xue Y, Lin K, Cui C. Purification and Initial Characterization of 3-Hydroxybenzoate 6-Hydroxylase From a Halophilic Martelella Strain AD-3. Front Microbiol 2018; 9:1335. [PMID: 30034371 PMCID: PMC6043778 DOI: 10.3389/fmicb.2018.01335] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2017] [Accepted: 05/31/2018] [Indexed: 11/20/2022] Open
Abstract
3-Hydroxybenzoate 6-hydroxylase, an NADH-dependent flavoprotein, can convert 3-hydroxybenzoate which is an important intermediate in the biodegradation of many aromatic hydrocarbons. 3-Hydroxybenzoate is metabolized by entering the TCA cycle through the gentisate pathway. We found a putative 3HB6H gene from a cluster that potentially encodes for gentisic acid degradation from a halophilic Martelella sp. strain AD-3. The corresponding protein was expressed with an N-terminal His-tag and purified by Ni2+-nitrilotriacetic acid affinity chromatography. The protein showed an overexpressed band of about 46 kDa by SDS–PAGE, and it was also proven that the enzyme contains FAD by absorption spectroscopy and HPLC analysis. The optimal activity of 3HB6H from strain AD-3 was observed in phosphate buffer (pH 8.0) at 37°C without salinity (NaCl) and metal salts. The Km values of 3-hydroxybenzoate 6-hydroxylase were determined to be 72.6 ± 10.1 μM and 104.1 ± 18.2 μM for 400 μM NADH and 3-hydroxybenzoate, respectively. Site-directed mutagenesis showed that residues 305, 306 and 308 are important for FAD binding. In addition, we found that Tyr221 and Gln305 of 3HB6H from strain AD-3 are involved in substrate binding.
Collapse
Affiliation(s)
- Xin Chen
- State Environmental Protection Key Laboratory of Environmental Risk Assessment and Control on Chemical Process, School of Resources and Environmental Engineering, East China University of Science and Technology, Shanghai, China
| | - Hongzhi Tang
- State Key Laboratory of Microbial Metabolism and School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai, China
| | - Yongdi Liu
- State Environmental Protection Key Laboratory of Environmental Risk Assessment and Control on Chemical Process, School of Resources and Environmental Engineering, East China University of Science and Technology, Shanghai, China
| | - Ping Xu
- State Key Laboratory of Microbial Metabolism and School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai, China
| | - Yong Xue
- Eco-environmental Protection Research Institute, Shanghai Academy of Agricultural Sciences, Shanghai, China
| | - Kuangfei Lin
- State Environmental Protection Key Laboratory of Environmental Risk Assessment and Control on Chemical Process, School of Resources and Environmental Engineering, East China University of Science and Technology, Shanghai, China
| | - Changzheng Cui
- State Environmental Protection Key Laboratory of Environmental Risk Assessment and Control on Chemical Process, School of Resources and Environmental Engineering, East China University of Science and Technology, Shanghai, China
| |
Collapse
|
25
|
Dong J, Fernández-Fueyo E, Hollmann F, Paul CE, Pesic M, Schmidt S, Wang Y, Younes S, Zhang W. Biokatalytische Oxidationsreaktionen - aus der Sicht eines Chemikers. Angew Chem Int Ed Engl 2018. [DOI: 10.1002/ange.201800343] [Citation(s) in RCA: 84] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Affiliation(s)
- JiaJia Dong
- Department of Biotechnology; Delft University of Technology; van der Maasweg 9 2629HZ Delft Niederlande
| | - Elena Fernández-Fueyo
- Department of Biotechnology; Delft University of Technology; van der Maasweg 9 2629HZ Delft Niederlande
| | - Frank Hollmann
- Department of Biotechnology; Delft University of Technology; van der Maasweg 9 2629HZ Delft Niederlande
| | - Caroline E. Paul
- Department of Biotechnology; Delft University of Technology; van der Maasweg 9 2629HZ Delft Niederlande
| | - Milja Pesic
- Department of Biotechnology; Delft University of Technology; van der Maasweg 9 2629HZ Delft Niederlande
| | - Sandy Schmidt
- Department of Biotechnology; Delft University of Technology; van der Maasweg 9 2629HZ Delft Niederlande
| | - Yonghua Wang
- School of Food Science and Engineering; South China University of Technology; Guangzhou 510640 P. R. China
| | - Sabry Younes
- Department of Biotechnology; Delft University of Technology; van der Maasweg 9 2629HZ Delft Niederlande
| | - Wuyuan Zhang
- Department of Biotechnology; Delft University of Technology; van der Maasweg 9 2629HZ Delft Niederlande
| |
Collapse
|
26
|
Deazaflavins as photocatalysts for the direct reductive regeneration of flavoenzymes. MOLECULAR CATALYSIS 2018. [DOI: 10.1016/j.mcat.2018.04.015] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
|
27
|
Huang H, Tao X, Jiang Y, Khan A, Wu Q, Yu X, Wu D, Chen Y, Ling Z, Liu P, Li X. The naphthalene catabolic protein NahG plays a key role in hexavalent chromium reduction in Pseudomonas brassicacearum LZ-4. Sci Rep 2017; 7:9670. [PMID: 28852154 PMCID: PMC5575117 DOI: 10.1038/s41598-017-10469-w] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2017] [Accepted: 08/10/2017] [Indexed: 11/09/2022] Open
Abstract
Soil contamination by PAH and heavy metals is a growing problem. Here, we showed that a new isolate, Pseudomonas brassicacearum strain LZ-4, can simultaneously degrade 98% of 6 mM naphthalene and reduce 92.4% of 500 μM hexavalent chromium [Cr (VI)] within 68 h. A draft genome sequence of strain LZ-4 (6,219,082 bp) revealed all the genes in the naphthalene catabolic pathway and some known Cr (VI) reductases. Interestingly, genes encoding naphthalene pathway components were upregulated in the presence of Cr (VI), and Cr (VI) reduction was elevated in the presence of naphthalene. We cloned and expressed these naphthalene catabolic genes and tested for Cr (VI) reduction, and found that NahG reduced 79% of 100 μM Cr (VI) in 5 minutes. Additionally, an nahG deletion mutant lost 52% of its Cr (VI) reduction ability compared to that of the wild-type strain. As nahG encodes a salicylate hydroxylase with flavin adenine dinucleotide (FAD) as a cofactor for electron transfer, Cr (VI) could obtain electrons from NADH through NahG-associated FAD. To the best of our knowledge, this is the first report of a protein involved in a PAH-degradation pathway that can reduce heavy metals, which provides new insights into heavy metal-PAH contamination remediation.
Collapse
Affiliation(s)
- Haiying Huang
- MOE Key Laboratory of Cell Activities and Stress Adaptations, School of Life Sciences, Lanzhou University, Lanzhou, Gansu, 730000, P.R. China
| | - Xuanyu Tao
- MOE Key Laboratory of Cell Activities and Stress Adaptations, School of Life Sciences, Lanzhou University, Lanzhou, Gansu, 730000, P.R. China
| | - Yiming Jiang
- MOE Key Laboratory of Cell Activities and Stress Adaptations, School of Life Sciences, Lanzhou University, Lanzhou, Gansu, 730000, P.R. China
| | - Aman Khan
- MOE Key Laboratory of Cell Activities and Stress Adaptations, School of Life Sciences, Lanzhou University, Lanzhou, Gansu, 730000, P.R. China
| | - Qi Wu
- MOE Key Laboratory of Cell Activities and Stress Adaptations, School of Life Sciences, Lanzhou University, Lanzhou, Gansu, 730000, P.R. China
| | - Xuan Yu
- MOE Key Laboratory of Cell Activities and Stress Adaptations, School of Life Sciences, Lanzhou University, Lanzhou, Gansu, 730000, P.R. China
| | - Dan Wu
- School of Life Sciences, Lanzhou University, Lanzhou, 730000, P.R. China
| | - Yong Chen
- MOE Key Laboratory of Cell Activities and Stress Adaptations, School of Life Sciences, Lanzhou University, Lanzhou, Gansu, 730000, P.R. China
| | - Zhenmin Ling
- MOE Key Laboratory of Cell Activities and Stress Adaptations, School of Life Sciences, Lanzhou University, Lanzhou, Gansu, 730000, P.R. China
| | - Pu Liu
- MOE Key Laboratory of Cell Activities and Stress Adaptations, School of Life Sciences, Lanzhou University, Lanzhou, Gansu, 730000, P.R. China
| | - Xiangkai Li
- MOE Key Laboratory of Cell Activities and Stress Adaptations, School of Life Sciences, Lanzhou University, Lanzhou, Gansu, 730000, P.R. China.
| |
Collapse
|
28
|
Montersino S, Te Poele E, Orru R, Westphal AH, Barendregt A, Heck AJR, van der Geize R, Dijkhuizen L, Mattevi A, van Berkel WJH. 3-Hydroxybenzoate 6-Hydroxylase from Rhodococcus jostii RHA1 Contains a Phosphatidylinositol Cofactor. Front Microbiol 2017; 8:1110. [PMID: 28670303 PMCID: PMC5472690 DOI: 10.3389/fmicb.2017.01110] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2017] [Accepted: 05/31/2017] [Indexed: 01/05/2023] Open
Abstract
3-Hydroxybenzoate 6-hydroxylase (3HB6H, EC 1.13.14.26) is a FAD-dependent monooxygenase involved in the catabolism of aromatic compounds in soil microorganisms. 3HB6H is unique among flavoprotein hydroxylases in that it harbors a phospholipid ligand. The purified protein obtained from expressing the gene encoding 3HB6H from Rhodococcus jostii RHA1 in the host Escherichia coli contains a mixture of phosphatidylglycerol and phosphatidylethanolamine, which are the major constituents of E. coli's cytoplasmic membrane. Here, we purified 3HB6H (RjHB6H) produced in the host R. jostii RHA#2 by employing a newly developed actinomycete expression system. Biochemical and biophysical analysis revealed that Rj3HB6H possesses similar catalytic and structural features as 3HB6H, but now contains phosphatidylinositol, which is a specific constituent of actinomycete membranes. Native mass spectrometry suggests that the lipid cofactor stabilizes monomer-monomer contact. Lipid analysis of 3HB6H from Pseudomonas alcaligenes NCIMB 9867 (Pa3HB6H) produced in E. coli supports the conclusion that 3HB6H enzymes have an intrinsic ability to bind phospholipids with different specificity, reflecting the membrane composition of their bacterial host.
Collapse
Affiliation(s)
- Stefania Montersino
- Laboratory of Biochemistry, Wageningen University and ResearchWageningen, Netherlands
| | - Evelien Te Poele
- Microbial Physiology, Groningen Biomolecular Sciences and Biotechnology Institute, University of GroningenGroningen, Netherlands
| | - Roberto Orru
- Department of Biology and Biotechnology, University of PaviaPavia, Italy
| | - Adrie H Westphal
- Laboratory of Biochemistry, Wageningen University and ResearchWageningen, Netherlands
| | - Arjan Barendregt
- Biomolecular Mass Spectrometry and Proteomics, Bijvoet Center for Biomolecular Research and Utrecht Institute for Pharmaceutical Research, Utrecht UniversityUtrecht, Netherlands
| | - Albert J R Heck
- Biomolecular Mass Spectrometry and Proteomics, Bijvoet Center for Biomolecular Research and Utrecht Institute for Pharmaceutical Research, Utrecht UniversityUtrecht, Netherlands
| | - Robert van der Geize
- Microbial Physiology, Groningen Biomolecular Sciences and Biotechnology Institute, University of GroningenGroningen, Netherlands
| | - Lubbert Dijkhuizen
- Microbial Physiology, Groningen Biomolecular Sciences and Biotechnology Institute, University of GroningenGroningen, Netherlands
| | - Andrea Mattevi
- Department of Biology and Biotechnology, University of PaviaPavia, Italy
| | - Willem J H van Berkel
- Laboratory of Biochemistry, Wageningen University and ResearchWageningen, Netherlands
| |
Collapse
|
29
|
Hutchinson JP, Rowland P, Taylor MRD, Christodoulou EM, Haslam C, Hobbs CI, Holmes DS, Homes P, Liddle J, Mole DJ, Uings I, Walker AL, Webster SP, Mowat CG, Chung CW. Structural and mechanistic basis of differentiated inhibitors of the acute pancreatitis target kynurenine-3-monooxygenase. Nat Commun 2017; 8:15827. [PMID: 28604669 PMCID: PMC5477544 DOI: 10.1038/ncomms15827] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2017] [Accepted: 04/28/2017] [Indexed: 12/31/2022] Open
Abstract
Kynurenine-3-monooxygenase (KMO) is a key FAD-dependent enzyme of tryptophan metabolism. In animal models, KMO inhibition has shown benefit in neurodegenerative diseases such as Huntington's and Alzheimer's. Most recently it has been identified as a target for acute pancreatitis multiple organ dysfunction syndrome (AP-MODS); a devastating inflammatory condition with a mortality rate in excess of 20%. Here we report and dissect the molecular mechanism of action of three classes of KMO inhibitors with differentiated binding modes and kinetics. Two novel inhibitor classes trap the catalytic flavin in a previously unobserved tilting conformation. This correlates with picomolar affinities, increased residence times and an absence of the peroxide production seen with previous substrate site inhibitors. These structural and mechanistic insights culminated in GSK065(C1) and GSK366(C2), molecules suitable for preclinical evaluation. Moreover, revising the repertoire of flavin dynamics in this enzyme class offers exciting new opportunities for inhibitor design. Kynurenine-3-monooxygenase (KMO) is an emerging clinical target for treatment of neurodegenerative diseases and acute pancreatitis. Here, the authors report potent inhibitors that bind KMO in an unexpected conformation, offering structural and mechanistic insights for future drug discovery ventures.
Collapse
Affiliation(s)
| | - Paul Rowland
- Platform Technologies and Science, GlaxoSmithKline, Stevenage SG1 2NY, UK
| | - Mark R D Taylor
- EastChem School of Chemistry, University of Edinburgh, Edinburgh EH9 3FJ, UK
| | | | - Carl Haslam
- Platform Technologies and Science, GlaxoSmithKline, Stevenage SG1 2NY, UK
| | - Clare I Hobbs
- Platform Technologies and Science, GlaxoSmithKline, Stevenage SG1 2NY, UK
| | - Duncan S Holmes
- Discovery Partnerships with Academia, GlaxoSmithKline, Stevenage, UK
| | - Paul Homes
- Platform Technologies and Science, GlaxoSmithKline, Stevenage SG1 2NY, UK
| | - John Liddle
- Discovery Partnerships with Academia, GlaxoSmithKline, Stevenage, UK
| | - Damian J Mole
- Medical Research Council Centre for Inflammation Research, Edinburgh EH16 4TJ, UK.,Clinical Surgery, University of Edinburgh, Edinburgh EH16 4SA, UK
| | - Iain Uings
- Discovery Partnerships with Academia, GlaxoSmithKline, Stevenage, UK
| | - Ann L Walker
- Discovery Partnerships with Academia, GlaxoSmithKline, Stevenage, UK
| | - Scott P Webster
- Centre for Cardiovascular Science, University of Edinburgh, Edinburgh EH16 4TJ, UK
| | - Christopher G Mowat
- EastChem School of Chemistry, University of Edinburgh, Edinburgh EH9 3FJ, UK
| | - Chun-Wa Chung
- Platform Technologies and Science, GlaxoSmithKline, Stevenage SG1 2NY, UK
| |
Collapse
|
30
|
Hicks KA, Yuen ME, Zhen WF, Gerwig TJ, Story RW, Kopp MC, Snider MJ. Structural and Biochemical Characterization of 6-Hydroxynicotinic Acid 3-Monooxygenase, A Novel Decarboxylative Hydroxylase Involved in Aerobic Nicotinate Degradation. Biochemistry 2016; 55:3432-46. [DOI: 10.1021/acs.biochem.6b00105] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Katherine A. Hicks
- Department
of Chemistry, SUNY Cortland, Cortland, New York 13045, United States
| | - Meigan E. Yuen
- Department
of Chemistry, SUNY Cortland, Cortland, New York 13045, United States
| | - Wei Feng Zhen
- Department
of Chemistry, SUNY Cortland, Cortland, New York 13045, United States
| | - Tyler J. Gerwig
- Department
of Chemistry, The College of Wooster, Wooster, Ohio 44691, United States
| | - Ryan W. Story
- Department
of Chemistry, The College of Wooster, Wooster, Ohio 44691, United States
| | - Megan C. Kopp
- Department
of Chemistry and Chemical Biology, Cornell University, Ithaca, New York 14853, United States
| | - Mark J. Snider
- Department
of Chemistry, The College of Wooster, Wooster, Ohio 44691, United States
| |
Collapse
|
31
|
Spadaro F, Scoffone VC, Chiarelli LR, Fumagalli M, Buroni S, Riccardi G, Forneris F. The Crystal Structure of Burkholderia cenocepacia DfsA Provides Insights into Substrate Recognition and Quorum Sensing Fatty Acid Biosynthesis. Biochemistry 2016; 55:3241-50. [PMID: 27198181 DOI: 10.1021/acs.biochem.6b00178] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
Burkholderia cenocepacia is a major concern among respiratory tract infections in cystic fibrosis patients. This pathogen is particularly difficult to treat because of its high level of resistance to the clinically relevant antimicrobial agents. In B. cenocepacia, the quorum sensing cell-cell communication system is involved in different processes that are important for bacterial virulence, such as biofilm formation and protease and siderophore production. Targeting the enzymes involved in this process represents a promising therapeutic approach. With the aim of finding effective quorum sensing inhibitors, we have determined the three-dimensional structure of B. cenocepacia diffusible factor synthase A, DfsA. This bifunctional crotonase (dehydratase/thioesterase) produces the characteristic quorum sensing molecule of B. cenocepacia, cis-2-dodecenoic acid or BDSF, starting from 3-hydroxydodecanoyl-acyl carrier protein. Unexpectedly, the crystal structure revealed the presence of a lipid molecule in the catalytic site of the enzyme, which was identified as dodecanoic acid. Our biochemical characterization shows that DfsA is able to use dodecanoyl-acyl carrier protein as a substrate, demonstrating that dodecanoic acid, the product of this reaction, is released very slowly from the DfsA active site, therefore acting as a DfsA inhibitor. This molecule shows an unprecedented conformational arrangement inside the DfsA active site. In contrast with previous hypotheses, our data illustrate how DfsA and closely related homologous enzymes can recognize long hydrophobic substrates without large conformational changes or assistance by additional regulator molecules. The elucidation of the substrate binding mode in DfsA provides the starting point for structure-based drug discovery studies targeting B. cenocepacia quorum sensing-assisted virulence.
Collapse
Affiliation(s)
- Francesca Spadaro
- Department of Biology and Biotechnology "Lazzaro Spallanzani", University of Pavia , Via Ferrata 9/A, 27100 Pavia, Italy
| | - Viola C Scoffone
- Department of Biology and Biotechnology "Lazzaro Spallanzani", University of Pavia , Via Ferrata 9/A, 27100 Pavia, Italy
| | - Laurent R Chiarelli
- Department of Biology and Biotechnology "Lazzaro Spallanzani", University of Pavia , Via Ferrata 9/A, 27100 Pavia, Italy
| | - Marco Fumagalli
- Department of Biology and Biotechnology "Lazzaro Spallanzani", University of Pavia , Via Ferrata 9/A, 27100 Pavia, Italy
| | - Silvia Buroni
- Department of Biology and Biotechnology "Lazzaro Spallanzani", University of Pavia , Via Ferrata 9/A, 27100 Pavia, Italy
| | - Giovanna Riccardi
- Department of Biology and Biotechnology "Lazzaro Spallanzani", University of Pavia , Via Ferrata 9/A, 27100 Pavia, Italy
| | - Federico Forneris
- Department of Biology and Biotechnology "Lazzaro Spallanzani", University of Pavia , Via Ferrata 9/A, 27100 Pavia, Italy
| |
Collapse
|
32
|
Eilers U, Dietzel L, Breitenbach J, Büchel C, Sandmann G. Identification of genes coding for functional zeaxanthin epoxidases in the diatom Phaeodactylum tricornutum. JOURNAL OF PLANT PHYSIOLOGY 2016; 192:64-70. [PMID: 26851888 DOI: 10.1016/j.jplph.2016.01.006] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/26/2015] [Revised: 01/15/2016] [Accepted: 01/18/2016] [Indexed: 05/21/2023]
Abstract
Phaeodactylum tricornutum like other diatoms synthesizes fucoxanthin and diadinoxanthin as major carotenoid end products. The genes involved have recently been assigned for early pathway steps. Beyond β-carotene, only gene candidates for β-carotene hydroxylase, zeaxanthin epoxidase and zeaxanthin de-epoxidase have been proposed from the available genome sequence. The two latter enzymes may be involved in the two different xanthophyll cycles which operate in P. tricornutum. The function of three putative zeaxanthin epoxidase genes (zep) was addressed by pathway complementation in the Arabidopsis thaliana Zep mutant npq2. Genes zep2 and zep3 were able to restore zeaxanthin epoxidation and a functional xanthophyll cycle but the corresponding enzymes exhibited different catalytic activities. Zep3 functioned as a zeaxanthin epoxidase whereas Zep2 exhibited a broader substrate specificity additionally converting lutein to lutein-5,6-epoxide. Although zep1 was transcribed and the protein could be identified after import into the chloroplast in A. thaliana, Zep1 was found not to be functional in zeaxanthin epoxidation. The non-photochemical quenching kinetics of wild type A. thaliana was only restored in transformant npq2-zep3.
Collapse
Affiliation(s)
- Ulrike Eilers
- Department of Molecular Bioscience, J.W. Goethe University, Max-v-Laue Str. 9, D-60438 Frankfurt, Germany
| | - Lars Dietzel
- Department of Molecular Bioscience, J.W. Goethe University, Max-v-Laue Str. 9, D-60438 Frankfurt, Germany
| | - Jürgen Breitenbach
- Department of Molecular Bioscience, J.W. Goethe University, Max-v-Laue Str. 9, D-60438 Frankfurt, Germany
| | - Claudia Büchel
- Department of Molecular Bioscience, J.W. Goethe University, Max-v-Laue Str. 9, D-60438 Frankfurt, Germany
| | - Gerhard Sandmann
- Department of Molecular Bioscience, J.W. Goethe University, Max-v-Laue Str. 9, D-60438 Frankfurt, Germany.
| |
Collapse
|
33
|
Sucharitakul J, Medhanavyn D, Pakotiprapha D, van Berkel WJH, Chaiyen P. Tyr217 and His213 are important for substrate binding and hydroxylation of 3-hydroxybenzoate 6-hydroxylase fromRhodococcus jostiiRHA1. FEBS J 2016; 283:860-81. [DOI: 10.1111/febs.13636] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2015] [Revised: 11/03/2015] [Accepted: 12/21/2015] [Indexed: 01/28/2023]
Affiliation(s)
- Jeerus Sucharitakul
- Department of Biochemistry; Faculty of Dentistry; Chulalongkorn University; Bangkok Thailand
| | - Dheeradhach Medhanavyn
- Department of Biochemistry and Center for Excellence in Proteins and Enzyme Technology; Faculty of Science; Mahidol University; Bangkok Thailand
| | - Danaya Pakotiprapha
- Department of Biochemistry and Center for Excellence in Proteins and Enzyme Technology; Faculty of Science; Mahidol University; Bangkok Thailand
| | | | - Pimchai Chaiyen
- Department of Biochemistry and Center for Excellence in Proteins and Enzyme Technology; Faculty of Science; Mahidol University; Bangkok Thailand
| |
Collapse
|
34
|
Ismail A, Leroux V, Smadja M, Gonzalez L, Lombard M, Pierrel F, Mellot-Draznieks C, Fontecave M. Coenzyme Q Biosynthesis: Evidence for a Substrate Access Channel in the FAD-Dependent Monooxygenase Coq6. PLoS Comput Biol 2016; 12:e1004690. [PMID: 26808124 PMCID: PMC4726752 DOI: 10.1371/journal.pcbi.1004690] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2015] [Accepted: 12/03/2015] [Indexed: 02/06/2023] Open
Abstract
Coq6 is an enzyme involved in the biosynthesis of coenzyme Q, a polyisoprenylated benzoquinone lipid essential to the function of the mitochondrial respiratory chain. In the yeast Saccharomyces cerevisiae, this putative flavin-dependent monooxygenase is proposed to hydroxylate the benzene ring of coenzyme Q (ubiquinone) precursor at position C5. We show here through biochemical studies that Coq6 is a flavoprotein using FAD as a cofactor. Homology models of the Coq6-FAD complex are constructed and studied through molecular dynamics and substrate docking calculations of 3-hexaprenyl-4-hydroxyphenol (4-HP6), a bulky hydrophobic model substrate. We identify a putative access channel for Coq6 in a wild type model and propose in silico mutations positioned at its entrance capable of partially (G248R and L382E single mutations) or completely (a G248R-L382E double-mutation) blocking access to the channel for the substrate. Further in vivo assays support the computational predictions, thus explaining the decreased activities or inactivation of the mutated enzymes. This work provides the first detailed structural information of an important and highly conserved enzyme of ubiquinone biosynthesis.
Collapse
Affiliation(s)
- Alexandre Ismail
- Laboratoire de Chimie des Processus Biologiques, UMR 8229 CNRS, UPMC Univ Paris 06, Collège de France, Paris, France
- Sup’Biotech, IONIS Education Group, Villejuif, France
| | - Vincent Leroux
- Paris Sciences et Lettres (PSL*), Collège de France, Center for Interdisciplinary Research in Biology (CIRB), INSERM U1050, Paris, France
| | - Myriam Smadja
- Laboratoire de Chimie des Processus Biologiques, UMR 8229 CNRS, UPMC Univ Paris 06, Collège de France, Paris, France
| | - Lucie Gonzalez
- Laboratoire de Chimie des Processus Biologiques, UMR 8229 CNRS, UPMC Univ Paris 06, Collège de France, Paris, France
| | - Murielle Lombard
- Laboratoire de Chimie des Processus Biologiques, UMR 8229 CNRS, UPMC Univ Paris 06, Collège de France, Paris, France
| | - Fabien Pierrel
- Université Grenoble Alpes, Laboratoire Adaptation et Pathogénie des Microorganismes, Grenoble, France
- CNRS, Laboratoire Adaptation et Pathogénie des Microorganismes, Grenoble, France
| | - Caroline Mellot-Draznieks
- Laboratoire de Chimie des Processus Biologiques, UMR 8229 CNRS, UPMC Univ Paris 06, Collège de France, Paris, France
| | - Marc Fontecave
- Laboratoire de Chimie des Processus Biologiques, UMR 8229 CNRS, UPMC Univ Paris 06, Collège de France, Paris, France
| |
Collapse
|
35
|
Riedel A, Heine T, Westphal AH, Conrad C, Rathsack P, van Berkel WJH, Tischler D. Catalytic and hydrodynamic properties of styrene monooxygenases from Rhodococcus opacus 1CP are modulated by cofactor binding. AMB Express 2015; 5:112. [PMID: 26054733 PMCID: PMC4460183 DOI: 10.1186/s13568-015-0112-9] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2015] [Accepted: 04/15/2015] [Indexed: 12/13/2022] Open
Abstract
Styrene monooxygenases (SMOs) are flavoenzymes catalyzing the epoxidation of styrene into styrene oxide. SMOs are composed of a monooxygenase (StyA) and a reductase (StyB). The latter delivers reduced FAD to StyA on the expense of NADH. We identified Rhodococcus opacus 1CP as the first microorganism to possess three different StyA isoforms occurring in two systems StyA1/StyA2B and StyA/StyB, respectively. The hydrodynamic properties of StyA isozymes were found to be modulated by the binding of the (reduced) FAD cofactor. StyA1 and SyA2B mainly occur as dimers in their active forms while StyA is a monomer. StyA1 showed the highest epoxidation activity and excellent enantioselectivity in aromatic sulfoxidation. The hydrodynamic and biocatalytic properties of SMOs from strain 1CP are of relevance for investigation of possible industrial applications.
Collapse
|
36
|
HipH Catalyzes the Hydroxylation of 4-Hydroxyisophthalate to Protocatechuate in 2,4-Xylenol Catabolism by Pseudomonas putida NCIMB 9866. Appl Environ Microbiol 2015; 82:724-31. [PMID: 26567311 DOI: 10.1128/aem.03105-15] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2015] [Accepted: 11/10/2015] [Indexed: 11/20/2022] Open
Abstract
In addition to growing on p-cresol, Pseudomonas putida NCIMB 9866 is the only reported strain capable of aerobically growing on 2,4-xylenol, which is listed as a priority pollutant by the U.S. Environmental Protection Agency. Several enzymes involved in the oxidation of the para-methyl group, as well as the corresponding genes, have previously been reported. The enzyme catalyzing oxidation of the catabolic intermediate 4-hydroxyisophthalate to the ring cleavage substrate protocatechuate was also purified from strain NCIMB 9866, but its genetic determinant is still unavailable. In this study, the gene hipH, encoding 4-hydroxyisophthalate hydroxylase, from strain NCIMB 9866 was cloned by transposon mutagenesis. Purified recombinant HipH-His6 was found to be a dimer protein with a molecular mass of approximately 110 kDa. HipH-His6 catalyzed the hydroxylation of 4-hydroxyisophthalate to protocatechuate with a specific activity of 1.54 U mg(-1) and showed apparent Km values of 11.40 ± 3.05 μM for 4-hydroxyisophthalate with NADPH and 11.23 ± 2.43 μM with NADH and similar Km values for NADPH and NADH (64.31 ± 13.16 and 72.76 ± 12.06 μM, respectively). The identity of protocatechuate generated from 4-hydroxyisophthalate hydroxylation by HipH-His6 has also been confirmed by high-performance liquid chromatography and mass spectrometry. Gene transcriptional analysis, gene knockout, and complementation indicated that hipH is essential for 2,4-xylenol catabolism but not for p-cresol catabolism in this strain. This fills a gap in our understanding of the gene that encodes a critical step in 2,4-xylenol catabolism and also provides another example of biochemical and genetic diversity of microbial catabolism of structurally similar compounds.
Collapse
|
37
|
Kanteev M, Bregman-Cohen A, Deri B, Shahar A, Adir N, Fishman A. A crystal structure of 2-hydroxybiphenyl 3-monooxygenase with bound substrate provides insights into the enzymatic mechanism. BIOCHIMICA ET BIOPHYSICA ACTA-PROTEINS AND PROTEOMICS 2015; 1854:1906-1913. [PMID: 26275805 DOI: 10.1016/j.bbapap.2015.08.002] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/13/2015] [Revised: 08/06/2015] [Accepted: 08/09/2015] [Indexed: 11/16/2022]
Abstract
2-Hydroxybiphenyl 3-monooxygenase (HbpA) is an FAD dependent monooxygenase which catalyzes the ortho-hydroxylation of a broad range of 2-substituted phenols in the presence of NADH and molecular oxygen. We have determined the structure of HbpA from the soil bacterium Pseudomonas azelaica HBP1 with bound 2-hydroxybiphenyl, as well as several variants, at a resolution of 2.3-2.5Å to investigate structure function correlations of the enzyme. An observed hydrogen bond between 2-hydroxybiphenyl and His48 in the active site confirmed the previously suggested role of this residue in substrate deprotonation. The entrance to the active site was confirmed by generating variant G255F which exhibited only 7% of the wild-type's specific activity of product formation, suggesting inhibition of substrate entrance into the active site by the large aromatic residue. Residue Arg242 is suggested to facilitate FAD movement and reduction as was previously reported in studies on the homologous protein para-hydroxybenzoate hydroxylase. In addition, it is suggested that Trp225, which is located in the active site, facilitates proper substrate entrance into the binding pocket in contrast to aklavinone-11-hydroxylase and para-hydroxybenzoate hydroxylase in which a residue at a similar position is responsible for substrate deprotonation. Structure function correlations described in this work will aid in the design of variants with improved activity and altered selectivity for potential industrial applications.
Collapse
Affiliation(s)
- Margarita Kanteev
- Department of Biotechnology and Food Engineering, Technion-Israel Institute of Technology, Haifa, Israel
| | - Almog Bregman-Cohen
- Department of Biotechnology and Food Engineering, Technion-Israel Institute of Technology, Haifa, Israel
| | - Batel Deri
- Department of Biotechnology and Food Engineering, Technion-Israel Institute of Technology, Haifa, Israel
| | - Anat Shahar
- Macromolecular Crystallography Research Center (MCRC), Department of Life Sciences & NIBN, Ben-Gurion University of the Negev, Beer-Sheva, Israel
| | - Noam Adir
- Schulich Faculty of Chemistry, Technion-Israel Institute of Technology, Haifa, Israel
| | - Ayelet Fishman
- Department of Biotechnology and Food Engineering, Technion-Israel Institute of Technology, Haifa, Israel.
| |
Collapse
|
38
|
Jensen CN, Mielke T, Farrugia JE, Frank A, Man H, Hart S, Turkenburg JP, Grogan G. Structures of the Apo and FAD-bound forms of 2-hydroxybiphenyl 3-monooxygenase (HbpA) locate activity hotspots identified by using directed evolution. Chembiochem 2015; 16:968-76. [PMID: 25737306 PMCID: PMC4515095 DOI: 10.1002/cbic.201402701] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2014] [Indexed: 11/09/2022]
Abstract
The FAD-dependent monooxygenase HbpA from Pseudomonas azelaica HBP1 catalyses the hydroxylation of 2-hydroxybiphenyl (2HBP) to 2,3-dihydroxybiphenyl (23DHBP). HbpA has been used extensively as a model for studying flavoprotein hydroxylases under process conditions, and has also been subjected to directed-evolution experiments that altered its catalytic properties. The structure of HbpA has been determined in its apo and FAD-complex forms to resolutions of 2.76 and 2.03 Å, respectively. Comparisons of the HbpA structure with those of homologues, in conjunction with a model of the reaction product in the active site, reveal His48 as the most likely acid/base residue to be involved in the hydroxylation mechanism. Mutation of His48 to Ala resulted in an inactive enzyme. The structures of HbpA also provide evidence that mutants achieved by directed evolution that altered activity are comparatively remote from the substrate-binding site.
Collapse
Affiliation(s)
- Chantel N Jensen
- York Structural Biology Laboratory, Department of Chemistry, University of York, Heslington, York, YO10 5DD (UK)
| | | | | | | | | | | | | | | |
Collapse
|
39
|
Luanloet T, Sucharitakul J, Chaiyen P. Selectivity of substrate binding and ionization of 2-methyl-3-hydroxypyridine-5-carboxylic acid oxygenase. FEBS J 2015; 282:3107-25. [PMID: 25639849 DOI: 10.1111/febs.13220] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2014] [Revised: 01/21/2015] [Accepted: 01/28/2015] [Indexed: 11/30/2022]
Abstract
2-Methyl-3-hydroxypyridine-5-carboxylic acid (MHPC) oxygenase (EC 1.14.12.4) from Pseudomonas sp. MA-1 is a flavin-dependent monooxygenase that catalyzes a hydroxylation and aromatic ring cleavage reaction. The functional roles of two residues, Tyr223 and Tyr82, located ~ 5 Å away from MHPC, were characterized using site-directed mutagenesis, along with ligand binding, product analysis and transient kinetic experiments. Mutation of Tyr223 resulted in enzyme variants that were impaired in their hydroxylation activity and had Kd values for substrate binding 5-10-fold greater than the wild-type enzyme. Because this residue is adjacent to the water molecule that is located next to the 3-hydroxy group of MHPC, the results indicate that the interaction between Tyr223, H2 O and the 3-hydroxyl group of MHPC are important for substrate binding and hydroxylation. By contrast, the Kd for substrate binding of Tyr82His and Tyr82Phe variants were similar to that of the wild-type enzyme. However, only ~ 40-50% of the substrate was hydroxylated in the reactions of both variants, whereas most of the substrate was hydroxylated in the wild-type enzyme reaction. In free solution, MHPC or 5-hydroxynicotinic acid exists in a mixture of monoanionic and tripolar ionic forms, whereas only the tripolar ionic form binds to the wild-type enzyme. The binding of tripolar ionic MHPC would allow efficient hydroxylation through an electrophilic aromatic substitution mechanism. For the Tyr82His and Tyr82Phe variants, both forms of substrates can bind to the enzymes, indicating that the mutation at Tyr82 abolished the selectivity of the enzyme towards the tripolar ionic form. Transient kinetic studies indicated that the hydroxylation rate constants of both Tyr82 variants are approximately two- to 2.5-fold higher than that of the wild-type enzyme. Altogether, our findings suggest that Tyr82 is important for the binding selectivity of MHPC oxygenase towards the tripolar ionic species, whereas the interaction between Tyr223 and the substrate is important for ensuring hydroxylation. These results highlight how the active site of a flavoenzyme is able to deal with the presence of multiple forms of a substrate in solution and ensure efficient hydroxylation.
Collapse
Affiliation(s)
- Thikumporn Luanloet
- Department of Biochemistry and Center of Excellence in Protein Structure & Function, Faculty of Science, Mahidol University, Bangkok, Thailand
| | - Jeerus Sucharitakul
- Department of Biochemistry, Faculty of Dentistry, Chulalongkorn University, Bangkok, Thailand
| | - Pimchai Chaiyen
- Department of Biochemistry and Center of Excellence in Protein Structure & Function, Faculty of Science, Mahidol University, Bangkok, Thailand
| |
Collapse
|
40
|
Abood A, Al-Fahad A, Scott A, Hosny AEDMS, Hashem AM, Fattah AMA, Race PR, Simpson TJ, Cox RJ. Kinetic characterisation of the FAD dependent monooxygenase TropB and investigation of its biotransformation potential. RSC Adv 2015. [DOI: 10.1039/c5ra06693j] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Achieving regio-specific hydroxylation of aromatic compounds remains a major challenge in synthetic chemistry.
Collapse
Affiliation(s)
- Amira Abood
- School
- of Chemistry
- University of Bristol
- UK
- Chemistry of Natural and Microbial Products Department
| | - Ahmed Al-Fahad
- School
- of Chemistry
- University of Bristol
- UK
- Chemistry Department
| | - Alan Scott
- School
- of Chemistry
- University of Bristol
- UK
| | | | - Amal M. Hashem
- Chemistry of Natural and Microbial Products Department
- National Research Centre
- Cairo
- Egypt
| | - Azza M. A. Fattah
- Chemistry of Natural and Microbial Products Department
- National Research Centre
- Cairo
- Egypt
| | | | | | - Russell J. Cox
- School
- of Chemistry
- University of Bristol
- UK
- Institut für Organische Chemie
| |
Collapse
|
41
|
Hu H, Zhang H, Gao Z, Wang D, Liu G, Xu J, Lan K, Dong Y. Structure of the type VI secretion phospholipase effector Tle1 provides insight into its hydrolysis and membrane targeting. ACTA ACUST UNITED AC 2014; 70:2175-85. [DOI: 10.1107/s1399004714012899] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2014] [Accepted: 06/03/2014] [Indexed: 08/30/2023]
Abstract
A diverse superfamily of phospholipases consisting of the type VI lipase effectors Tle1–Tle5 secreted by the bacterial type VI secretion system (T6SS) have recently been identified as antibacterial effectors that hydrolyze membrane phospholipids. These effectors show no significant homology to known lipases, and their mechanism of membrane targeting and hydrolysis of phospholipids remains unknown. Here, the crystal structure of Tle1 (∼96.5 kDa) fromPseudomonas aeruginosarefined to 2.0 Å resolution is reported, representing the first structure of this superfamily. Its overall structure can be divided into two distinct parts, the phospholipase catalytic module and the putative membrane-anchoring module; this arrangement has not previously been observed in known lipase structures. The phospholipase catalytic module has a canonical α/β-hydrolase fold and mutation of any residue in the Ser-Asp-His catalytic triad abolishes its toxicity. The putative membrane-anchoring module adopts an open conformation composed of three amphipathic domains, and its partial folds are similar to those of several periplasmic or membrane proteins. A cell-toxicity assay revealed that the putative membrane-anchoring module is critical to Tle1 antibacterial activity. A molecular-dynamics (MD) simulation system in which the putative membrane-anchoring module embedded into a bilayer was stable over 50 ns. These structure–function studies provide insight into the hydrolysis and membrane-targeting process of the unique phospholipase Tle1.
Collapse
|
42
|
Ceccoli RD, Bianchi DA, Rial DV. Flavoprotein monooxygenases for oxidative biocatalysis: recombinant expression in microbial hosts and applications. Front Microbiol 2014; 5:25. [PMID: 24567729 PMCID: PMC3915288 DOI: 10.3389/fmicb.2014.00025] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2013] [Accepted: 01/14/2014] [Indexed: 11/21/2022] Open
Abstract
External flavoprotein monooxygenases comprise a group of flavin-dependent oxidoreductases that catalyze the insertion of one atom of molecular oxygen into an organic substrate and the second atom is reduced to water. These enzymes are involved in a great number of metabolic pathways both in prokaryotes and eukaryotes. Flavoprotein monooxygenases have attracted the attention of researchers for several decades and the advent of recombinant DNA technology caused a great progress in the field. These enzymes are subjected to detailed biochemical and structural characterization and some of them are also regarded as appealing oxidative biocatalysts for the production of fine chemicals and valuable intermediates toward active pharmaceutical ingredients due to their high chemo-, stereo-, and regioselectivity. Here, we review the most representative reactions catalyzed both in vivo and in vitro by prototype flavoprotein monooxygenases, highlighting the strategies employed to produce them recombinantly, to enhance the yield of soluble proteins, and to improve cofactor regeneration in order to obtain versatile biocatalysts. Although we describe the most outstanding features of flavoprotein monooxygenases, we mainly focus on enzymes that were cloned, expressed and used for biocatalysis during the last years.
Collapse
Affiliation(s)
- Romina D Ceccoli
- Área Biología Molecular, Departamento de Ciencias Biológicas, Facultad de Ciencias Bioquímicas y Farmacéuticas, Universidad Nacional de Rosario CONICET, Rosario, Argentina
| | - Dario A Bianchi
- Instituto de Química Rosario (IQUIR, CONICET-UNR), Área Análisis de Medicamentos, Departamento de Química Orgánica, Facultad de Ciencias Bioquímicas y Farmacéuticas, Universidad Nacional de Rosario Rosario, Argentina
| | - Daniela V Rial
- Área Biología Molecular, Departamento de Ciencias Biológicas, Facultad de Ciencias Bioquímicas y Farmacéuticas, Universidad Nacional de Rosario CONICET, Rosario, Argentina
| |
Collapse
|
43
|
Huijbers MME, Montersino S, Westphal AH, Tischler D, van Berkel WJH. Flavin dependent monooxygenases. Arch Biochem Biophys 2013; 544:2-17. [PMID: 24361254 DOI: 10.1016/j.abb.2013.12.005] [Citation(s) in RCA: 364] [Impact Index Per Article: 33.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2013] [Revised: 12/06/2013] [Accepted: 12/09/2013] [Indexed: 11/29/2022]
Abstract
Flavin-dependent monooxygenases catalyze a wide variety of chemo-, regio- and enantioselective oxygenation reactions. As such, they are involved in key biological processes ranging from catabolism, detoxification and biosynthesis, to light emission and axon guidance. Based on fold and function, flavin-dependent monooxygenases can be distributed into eight groups. Groups A and B comprise enzymes that rely on NAD(P)H as external electron donor. Groups C-F are two-protein systems, composed of a monooxygenase and a flavin reductase. Groups G and H comprise internal monooxygenases that reduce the flavin cofactor through substrate oxidation. Recently, many new flavin-dependent monooxygenases have been discovered. In addition to posing basic enzymological questions, these proteins attract attention of pharmaceutical and fine-chemical industries, given their importance as regio- and enantioselective biocatalysts. In this review we present an update of the classification of flavin-dependent monooxygenases and summarize the latest advances in our understanding of their catalytic and structural properties.
Collapse
Affiliation(s)
- Mieke M E Huijbers
- Laboratory of Biochemistry, Wageningen University, Dreijenlaan 3, 6703 HA Wageningen, The Netherlands
| | - Stefania Montersino
- Laboratory of Biochemistry, Wageningen University, Dreijenlaan 3, 6703 HA Wageningen, The Netherlands
| | - Adrie H Westphal
- Laboratory of Biochemistry, Wageningen University, Dreijenlaan 3, 6703 HA Wageningen, The Netherlands
| | - Dirk Tischler
- Laboratory of Biochemistry, Wageningen University, Dreijenlaan 3, 6703 HA Wageningen, The Netherlands; Interdisciplinary Ecological Center, TU Bergakademie Freiberg, Leipziger Str. 29, 09599 Freiberg, Germany
| | - Willem J H van Berkel
- Laboratory of Biochemistry, Wageningen University, Dreijenlaan 3, 6703 HA Wageningen, The Netherlands.
| |
Collapse
|
44
|
Sucharitakul J, Tongsook C, Pakotiprapha D, van Berkel WJH, Chaiyen P. The reaction kinetics of 3-hydroxybenzoate 6-hydroxylase from Rhodococcus jostii RHA1 provide an understanding of the para-hydroxylation enzyme catalytic cycle. J Biol Chem 2013; 288:35210-21. [PMID: 24129570 DOI: 10.1074/jbc.m113.515205] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023] Open
Abstract
3-Hydroxybenzoate 6-hydroxylase (3HB6H) from Rhodococcus jostii RHA1 is an NADH-specific flavoprotein monooxygenase that catalyzes the para-hydroxylation of 3-hydroxybenzoate (3HB) to form 2,5-dihydroxybenzoate (2,5-DHB). Based on results from stopped-flow spectrophotometry, the reduced enzyme-3HB complex reacts with oxygen to form a C4a-peroxy flavin with a rate constant of 1.13 ± 0.01 × 10(6) m(-1) s(-1) (pH 8.0, 4 °C). This intermediate is subsequently protonated to form a C4a-hydroperoxyflavin with a rate constant of 96 ± 3 s(-1). This step shows a solvent kinetic isotope effect of 1.7. Based on rapid-quench measurements, the hydroxylation occurs with a rate constant of 36 ± 2 s(-1). 3HB6H does not exhibit substrate inhibition on the flavin oxidation step, a common characteristic found in most ortho-hydroxylation enzymes. The apparent kcat at saturating concentrations of 3HB, NADH, and oxygen is 6.49 ± 0.02 s(-1). Pre-steady state and steady-state kinetic data were used to construct the catalytic cycle of the reaction. The data indicate that the steps of product release (11.7 s(-1)) and hydroxylation (36 ± 2 s(-1)) partially control the overall turnover.
Collapse
Affiliation(s)
- Jeerus Sucharitakul
- From the Department of Biochemistry, Faculty of Dentistry, Chulalongkorn University, Henri Dunant Road, Patumwan, Bangkok 10330, Thailand
| | | | | | | | | |
Collapse
|