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Doden HL, Pollet RM, Mythen SM, Wawrzak Z, Devendran S, Cann I, Koropatkin NM, Ridlon JM. Structural and biochemical characterization of 20β-hydroxysteroid dehydrogenase from Bifidobacterium adolescentis strain L2-32. J Biol Chem 2019; 294:12040-12053. [PMID: 31209107 DOI: 10.1074/jbc.ra119.009390] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2019] [Revised: 06/11/2019] [Indexed: 01/20/2023] Open
Abstract
Anaerobic bacteria inhabiting the human gastrointestinal tract have evolved various enzymes that modify host-derived steroids. The bacterial steroid-17,20-desmolase pathway cleaves the cortisol side chain, forming pro-androgens predicted to impact host physiology. Bacterial 20β-hydroxysteroid dehydrogenase (20β-HSDH) regulates cortisol side-chain cleavage by reducing the C-20 carboxyl group on cortisol, yielding 20β-dihydrocortisol. Recently, the gene encoding 20β-HSDH in Butyricicoccus desmolans ATCC 43058 was reported, and a nonredundant protein search yielded a candidate 20β-HSDH gene in Bifidobacterium adolescentis strain L2-32. B. adolescentis 20β-HSDH could regulate cortisol side-chain cleavage by limiting pro-androgen formation in bacteria such as Clostridium scindens and 21-dehydroxylation by Eggerthella lenta Here, the putative B. adolescentis 20β-HSDH was cloned, overexpressed, and purified. 20β-HSDH activity was confirmed through whole-cell and pure enzymatic assays, and it is specific for cortisol. Next, we solved the structures of recombinant 20β-HSDH in both the apo- and holo-forms at 2.0-2.2 Å resolutions, revealing close overlap except for rearrangements near the active site. Interestingly, the structures contain a large, flexible N-terminal region that was investigated by gel-filtration chromatography and CD spectroscopy. This extended N terminus is important for protein stability because deletions of varying lengths caused structural changes and reduced enzymatic activity. A nonconserved extended N terminus was also observed in several short-chain dehydrogenase/reductase family members. B. adolescentis strains capable of 20β-HSDH activity could alter glucocorticoid metabolism in the gut and thereby serve as potential probiotics for the management of androgen-dependent diseases.
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Affiliation(s)
- Heidi L Doden
- Microbiome Metabolic Engineering Theme, Carl R. Woese Institute for Genomic Biology, Urbana, Illinois 61801; Department of Animal Sciences, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801
| | - Rebecca M Pollet
- Department of Microbiology and Immunology, University of Michigan Medical School, Ann Arbor, Michigan 48109
| | - Sean M Mythen
- Microbiome Metabolic Engineering Theme, Carl R. Woese Institute for Genomic Biology, Urbana, Illinois 61801; Department of Animal Sciences, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801
| | - Zdzislaw Wawrzak
- Northwestern Synchrotron Research Center-LS-CAT, Northwestern University, Argonne, Illinois 60439
| | - Saravanan Devendran
- Microbiome Metabolic Engineering Theme, Carl R. Woese Institute for Genomic Biology, Urbana, Illinois 61801; Department of Animal Sciences, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801
| | - Isaac Cann
- Microbiome Metabolic Engineering Theme, Carl R. Woese Institute for Genomic Biology, Urbana, Illinois 61801; Department of Animal Sciences, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801; Department of Microbiology, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801
| | - Nicole M Koropatkin
- Department of Microbiology and Immunology, University of Michigan Medical School, Ann Arbor, Michigan 48109
| | - Jason M Ridlon
- Microbiome Metabolic Engineering Theme, Carl R. Woese Institute for Genomic Biology, Urbana, Illinois 61801; Department of Animal Sciences, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801; Cancer Center of Illinois, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801; Division of Nutritional Sciences, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801.
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Harris SC, Devendran S, Méndez- García C, Mythen SM, Wright CL, Fields CJ, Hernandez AG, Cann I, Hylemon PB, Ridlon JM. Bile acid oxidation by Eggerthella lenta strains C592 and DSM 2243 T. Gut Microbes 2018; 9:523-539. [PMID: 29617190 PMCID: PMC6287680 DOI: 10.1080/19490976.2018.1458180] [Citation(s) in RCA: 37] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/03/2023] Open
Abstract
Strains of Eggerthella lenta are capable of oxidation-reduction reactions capable of oxidizing and epimerizing bile acid hydroxyl groups. Several genes encoding these enzymes, known as hydroxysteroid dehydrogenases (HSDH) have yet to be identified. It is also uncertain whether the products of E. lenta bile acid metabolism are further metabolized by other members of the gut microbiota. We characterized a novel human fecal isolate identified as E. lenta strain C592. The complete genome of E. lenta strain C592 was sequenced and comparative genomics with the type strain (DSM 2243) revealed high conservation, but some notable differences. E. lenta strain C592 falls into group III, possessing 3α, 3β, 7α, and 12α-hydroxysteroid dehydrogenase (HSDH) activity, as determined by mass spectrometry of thin layer chromatography (TLC) separated metabolites of primary and secondary bile acids. Incubation of E. lenta oxo-bile acid and iso-bile acid metabolites with whole-cells of the high-activity bile acid 7α-dehydroxylating bacterium, Clostridium scindens VPI 12708, resulted in minimal conversion of oxo-derivatives to lithocholic acid (LCA). Further, Iso-chenodeoxycholic acid (iso-CDCA; 3β,7α-dihydroxy-5β-cholan-24-oic acid) was not metabolized by C. scindens. We then located a gene encoding a novel 12α-HSDH in E. lenta DSM 2243, also encoded by strain C592, and the recombinant purified enzyme was characterized and substrate-specificity determined. Genomic analysis revealed genes encoding an Rnf complex (rnfABCDEG), an energy conserving hydrogenase (echABCDEF) complex, as well as what appears to be a complete Wood-Ljungdahl pathway. Our prediction that by changing the gas atmosphere from nitrogen to hydrogen, bile acid oxidation would be inhibited, was confirmed. These results suggest that E. lenta is an important bile acid metabolizing gut microbe and that the gas atmosphere may be an important and overlooked regulator of bile acid metabolism in the gut.
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Affiliation(s)
- Spencer C. Harris
- Department of Microbiology and Immunology, Virginia Commonwealth University, Richmond, VA, USA,McGuire Veterans Affairs, Richmond, VA, USA
| | - Saravanan Devendran
- Department of Animal Sciences, University of Illinois at Urbana-Champaign, Urbana, IL, USA,Microbiome Metabolic Engineering Theme, Carl R. Woese Institute for Genomic Biology, University of Illinois at Urbana-Champaign, Urbana, IL, USA
| | | | - Sean M. Mythen
- Department of Animal Sciences, University of Illinois at Urbana-Champaign, Urbana, IL, USA,Microbiome Metabolic Engineering Theme, Carl R. Woese Institute for Genomic Biology, University of Illinois at Urbana-Champaign, Urbana, IL, USA
| | - Chris L. Wright
- Keck Center for Biotechnology, University of Illinois at Urbana-Champaign, Urbana, IL, USA
| | - Christopher J. Fields
- Keck Center for Biotechnology, University of Illinois at Urbana-Champaign, Urbana, IL, USA
| | - Alvaro G. Hernandez
- Keck Center for Biotechnology, University of Illinois at Urbana-Champaign, Urbana, IL, USA
| | - Isaac Cann
- Department of Animal Sciences, University of Illinois at Urbana-Champaign, Urbana, IL, USA,Microbiome Metabolic Engineering Theme, Carl R. Woese Institute for Genomic Biology, University of Illinois at Urbana-Champaign, Urbana, IL, USA,Division of Nutritional Sciences, University of Illinois at Urbana-Champaign, Urbana, IL, USA,Energy Biosciences Institute, University of Illinois at Urbana-Champaign, Urbana, IL, USA
| | - Phillip B. Hylemon
- Department of Microbiology and Immunology, Virginia Commonwealth University, Richmond, VA, USA,McGuire Veterans Affairs, Richmond, VA, USA
| | - Jason M. Ridlon
- Department of Microbiology and Immunology, Virginia Commonwealth University, Richmond, VA, USA,Department of Animal Sciences, University of Illinois at Urbana-Champaign, Urbana, IL, USA,Microbiome Metabolic Engineering Theme, Carl R. Woese Institute for Genomic Biology, University of Illinois at Urbana-Champaign, Urbana, IL, USA,Division of Nutritional Sciences, University of Illinois at Urbana-Champaign, Urbana, IL, USA,Cancer Center of Illinois, University of Illinois at Urbana-Champaign, Urbana, IL, USA,CONTACT Jason M. Ridlon Department of Animal Sciences, University of Illinois at Urbana-Champaign, Urbana, IL USA
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Devendran S, Mythen SM, Ridlon JM. The desA and desB genes from Clostridium scindens ATCC 35704 encode steroid-17,20-desmolase. J Lipid Res 2018; 59:1005-1014. [PMID: 29572237 DOI: 10.1194/jlr.m083949] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2018] [Revised: 03/07/2018] [Indexed: 12/27/2022] Open
Abstract
Clostridium scindens is a gut microbe capable of removing the side-chain of cortisol, forming 11β-hydro-xyandrostenedione. A cortisol-inducible operon (desABCD) was previously identified in C. scindens ATCC 35704 by RNA-Seq. The desC gene was shown to encode a cortisol 20α-hydroxysteroid dehydrogenase (20α-HSDH). The desD encodes a protein annotated as a member of the major facilitator family, predicted to function as a cortisol transporter. The desA and desB genes are annotated as N-terminal and C-terminal transketolases, respectively. We hypothesized that the DesAB forms a complex and has steroid-17,20-desmolase activity. We cloned the desA and desB genes from C. scindens ATCC 35704 in pETDuet for overexpression in Escherichia coli The purified recombinant DesAB was determined to be a 142 ± 5.4 kDa heterotetramer. We developed an enzyme-linked continuous spectrophotometric assay to quantify steroid-17,20-desmolase. This was achieved by coupling DesAB-dependent formation of 11β-hydroxyandrostenedione with the NADPH-dependent reduction of the steroid 17-keto group by a recombinant 17β-HSDH from the filamentous fungus, Cochliobolus lunatus The pH optimum for the coupled assay was 7.0 and kinetic constants using cortisol as substrate were Km of 4.96 ± 0.57 µM and kcat of 0.87 ± 0.076 min-1 Substrate-specificity studies revealed that rDesAB recognized substrates regardless of 11β-hydroxylation, but had an absolute requirement for 17,21-dihydroxy 20-ketosteroids.
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Affiliation(s)
- Saravanan Devendran
- Microbiome Metabolic Engineering Theme University of Illinois at Urbana-Champaign, Urbana, IL; Department of Animal Sciences, University of Illinois at Urbana-Champaign, Urbana, IL
| | - Sean M Mythen
- Microbiome Metabolic Engineering Theme University of Illinois at Urbana-Champaign, Urbana, IL; Department of Animal Sciences, University of Illinois at Urbana-Champaign, Urbana, IL
| | - Jason M Ridlon
- Microbiome Metabolic Engineering Theme University of Illinois at Urbana-Champaign, Urbana, IL; Department of Animal Sciences, University of Illinois at Urbana-Champaign, Urbana, IL; Computing Genomes for Reproductive Health Theme, Carl R. Woese Institute for Genomic Biology, University of Illinois at Urbana-Champaign, Urbana, IL; Division of Nutritional Sciences, University of Illinois at Urbana-Champaign, Urbana, IL; Cancer Center of Illinois, University of Illinois at Urbana-Champaign, Urbana, IL; Department of Microbiology & Immunology, Virginia Commonwealth University School of Medicine, Richmond, VA.
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Harris SC, Devendran S, Alves JMP, Mythen SM, Hylemon PB, Ridlon JM. Identification of a gene encoding a flavoprotein involved in bile acid metabolism by the human gut bacterium Clostridium scindens ATCC 35704. Biochim Biophys Acta Mol Cell Biol Lipids 2017; 1863:276-283. [PMID: 29217478 DOI: 10.1016/j.bbalip.2017.12.001] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2017] [Revised: 11/28/2017] [Accepted: 12/01/2017] [Indexed: 02/08/2023]
Abstract
BACKGROUND The multi-step bile acid 7α-dehydroxylating pathway by which a few species of Clostridium convert host primary bile acids to toxic secondary bile acids is of great importance to gut microbiome structure and host physiology and disease. While genes in the oxidative arm of the 7α-dehydroxylating pathway have been identified, genes in the reductive arm of the pathway are still obscure. METHODS We identified a candidate flavoprotein-encoding gene predicted to metabolize steroids. This gene was cloned and overexpressed in E. coli and affinity purified. Reaction substrate and product were separated by thin layer chromatography and identified by liquid chromatograph mass spectrometry-ion trap-time of flight (LCMS-IT-TOF). Phylogenetic analysis of the amino acid sequence was performed. RESULTS We report the identification of a gene encoding a flavoprotein (EDS08212.1) involved in secondary bile acid metabolism by Clostridium scindens ATCC 35704 and related species. Purified rEDS08212.1 catalyzed formation of a product from 3-dehydro-deoxycholic acid that UPLC-IT-TOF-MS analysis suggests loses 4amu. Our phylogeny identified this gene in other bile acid 7α-dehydroxylating bacteria. CONCLUSIONS These data suggest formation of a product, 3-dehydro-4,6-deoxycholic acid, a recognized intermediate in the reductive arm of bile acid 7α-dehydroxylation pathway and the first report of a gene in the reductive arm of the bile acid 7α-dehydroxylating pathway.
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Affiliation(s)
- Spencer C Harris
- Department of Microbiology and Immunology, Virginia Commonwealth University, Richmond, VA, USA
| | - Saravanan Devendran
- Department of Animal Sciences, University of Illinois at Urbana-Champaign, Urbana, IL, USA; Microbiome Metabolic Engineering Theme, Carl R. Woese Institute for Genomic Biology, University of Illinois at Urbana-Champaign, Urbana, IL, USA
| | - João M P Alves
- Department of Parasitology, Institute of Biomedical Sciences, University of São Paulo, São Paulo, Brazil
| | - Sean M Mythen
- Department of Animal Sciences, University of Illinois at Urbana-Champaign, Urbana, IL, USA; Microbiome Metabolic Engineering Theme, Carl R. Woese Institute for Genomic Biology, University of Illinois at Urbana-Champaign, Urbana, IL, USA
| | - Phillip B Hylemon
- Department of Microbiology and Immunology, Virginia Commonwealth University, Richmond, VA, USA
| | - Jason M Ridlon
- Department of Microbiology and Immunology, Virginia Commonwealth University, Richmond, VA, USA; Department of Animal Sciences, University of Illinois at Urbana-Champaign, Urbana, IL, USA; Microbiome Metabolic Engineering Theme, Carl R. Woese Institute for Genomic Biology, University of Illinois at Urbana-Champaign, Urbana, IL, USA.
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