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Li J, Kumar A, Lewis JC. Non-native Intramolecular Radical Cyclization Catalyzed by a B 12 -Dependent Enzyme. Angew Chem Int Ed Engl 2023; 62:e202312893. [PMID: 37874184 PMCID: PMC11328698 DOI: 10.1002/anie.202312893] [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: 09/01/2023] [Revised: 10/12/2023] [Accepted: 10/23/2023] [Indexed: 10/25/2023]
Abstract
Despite the unique reactivity of vitamin B12 and its derivatives, B12 -dependent enzymes remain underutilized in biocatalysis. In this study, we repurposed the B12 -dependent transcription factor CarH to enable non-native radical cyclization reactions. An engineered variant of this enzyme, CarH*, catalyzes the formation γ- and δ-lactams through either redox-neutral or reductive ring closure with marked enhancement of reactivity and selectivity relative to the free B12 cofactor. CarH* also catalyzes an unusual spirocyclization by dearomatization of pendant arenes to produce bicyclic 1,3-diene products instead of 1,4-dienes provided by existing methods. These results and associated mechanistic studies highlight the importance of protein scaffolds for controlling the reactivity of B12 and expanding the synthetic utility of B12 -dependent enzymes.
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Affiliation(s)
- Jianbin Li
- Department of Chemistry, Indiana University, Bloomington, IN 47405, USA
| | - Amardeep Kumar
- Department of Chemistry, Indiana University, Bloomington, IN 47405, USA
| | - Jared C Lewis
- Department of Chemistry, Indiana University, Bloomington, IN 47405, USA
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2
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Nara S, Parasher G, Malhotra BD, Rawat M. Novel role of folate (vitamin B9) released by fermenting bacteria under Human Intestine like environment. Sci Rep 2023; 13:20226. [PMID: 37980374 PMCID: PMC10657476 DOI: 10.1038/s41598-023-47243-0] [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: 07/03/2023] [Accepted: 11/10/2023] [Indexed: 11/20/2023] Open
Abstract
The anaerobic region of the gastrointestinal (GI) tract has been replicated in the anaerobic chamber of a microbial fuel cell (MFC). Electroactive biomolecules released by the facultative anaerobes (Providencia rettgeri) under anoxic conditions have been studied for their potential role for redox balance. MALDI study reveals the presence of vitamin B9 (folate), 6-methylpterin, para-aminobenzoic acid (PABA) and pteroic acid called pterin pool. ATR-FTIR studies further confirm the presence of the aromatic ring and side chains of folate, 6-methylpterin and PABA groups. The photoluminescence spectra of the pool exhibit the maximum emission at 420, 425, 440, and 445 nm when excited by 310, 325, 350, and 365 nm wavelengths (day 20 sample) highlighting the presence of tunable bands. The cyclic voltammetric studies indicate the active participation of pterin pool molecules in the transfer of electrons with redox potentials at - 0.2 V and - 0.4 V for p-aminobenzoate and pterin groups, respectively. In addition, it is observed that under prolonged conditions of continuous oxidative stress (> 20 days), quinonoid tetrahydrofolate is formed, leading to temporary storage of charge. The results of the present study may potentially be useful in designing effective therapeutic strategies for the management of various GI diseases by promoting or blocking folate receptors.
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Affiliation(s)
- Sharda Nara
- Nanobioelectronics Laboratory, Department of Biotechnology, Delhi Technological University, Delhi, 110042, India
| | - Gulshan Parasher
- Division of Gastroenterology and Hepatology, Department of Internal Medicine, University of New Mexico School of Medicine, Albuquerque, NM, 87131, USA
| | - Bansi Dhar Malhotra
- Nanobioelectronics Laboratory, Department of Biotechnology, Delhi Technological University, Delhi, 110042, India.
- Environmental Sciences & Biomedical Metrology, CSIR-National Physical Laboratory, Dr K.S. Krishnan Road, New Delhi, 110012, India.
| | - Manmeet Rawat
- Division of Gastroenterology and Hepatology, Department of Internal Medicine, University of New Mexico School of Medicine, Albuquerque, NM, 87131, USA.
- Division of Gastroenterology and Hepatology, Department of Medicine, The Penn State University College of Medicine, Penn State University, 500 University Drive, Hershey, PA, 17033, USA.
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3
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Zhang M, Li R, Fan X, Zhang S, Liao L, Xu X, Guo Y. Correlation of several forms of folic acid with endometrial cancer: cross-sectional data from the National Health and Nutrition Examination Surveys (NHANES) 2011-2018. J Cancer Res Clin Oncol 2023; 149:13619-13629. [PMID: 37515615 DOI: 10.1007/s00432-023-05177-0] [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: 06/30/2023] [Accepted: 07/10/2023] [Indexed: 07/31/2023]
Abstract
OBJECTIVE Endometrial cancer (EC) is a common malignancy of the female reproductive system and although most patients have a good prognosis, 20-30% of patients with advanced disease have a poor prognosis. There are currently no reliable biomarkers for early diagnosis and effective prognostic improvement of the disease. The purpose of this study was to explore the correlation between different forms of folic acid and endometrial cancer. METHODS This study included 8809 female subjects aged ≥ 20 years in the NHANES database from 2011 to 2018, including 8738 non-oncology patients and 71 EC patients. Selection bias was reduced using 1:1 propensity score matching (PSM) method. Restricted cubic spline (RCS) was plotted to explore the non-linear relationship between different forms of folic acid and EC. RESULT Using data from the NHANES database from 2011 to 2018, the association between folic acid and the risk of developing EC was assessed. The results of the 1:1 ratio propensity score matching (PSM) showed 68 each for EC patients and non-oncology participants. Total serum folate, 5-methyltetrahydrofolate (5-methylTHF), 5-formyltetrahydrofolate (5-formylTHF), tetrahydrofolate (THF) and 5,10-methylenetetrahydrofolate (5,10-methenylTHF) were significantly correlated with EC (p < 0.05). In addition, the RCS showed a significant non-linear correlation between THF and 5,10-formyl THF and the risk of developing EC. CONCLUSION The results of this study showed that changes in serum total folate, 5-methylTHF, 5-formylTHF, THF and 5,10-methenylTHF were related to EC.
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Affiliation(s)
- Meng Zhang
- Department of Gynecology, Second Hospital of Lanzhou University, Cuiyingmen No. 82, Chengguan District, 730000, Lanzhou, Gansu, People's Republic of China
| | - Ruiping Li
- Department of Gynecology, Second Hospital of Lanzhou University, Cuiyingmen No. 82, Chengguan District, 730000, Lanzhou, Gansu, People's Republic of China
| | - Xuefen Fan
- Department of Gynecology, Second Hospital of Lanzhou University, Cuiyingmen No. 82, Chengguan District, 730000, Lanzhou, Gansu, People's Republic of China
| | - Shan Zhang
- Department of Gynecology, Second Hospital of Lanzhou University, Cuiyingmen No. 82, Chengguan District, 730000, Lanzhou, Gansu, People's Republic of China
| | - Lixin Liao
- Department of Gynecology, Second Hospital of Lanzhou University, Cuiyingmen No. 82, Chengguan District, 730000, Lanzhou, Gansu, People's Republic of China
| | - Xin Xu
- Department of Gynecology, Second Hospital of Lanzhou University, Cuiyingmen No. 82, Chengguan District, 730000, Lanzhou, Gansu, People's Republic of China
| | - Yuzhen Guo
- Department of Gynecology, Second Hospital of Lanzhou University, Cuiyingmen No. 82, Chengguan District, 730000, Lanzhou, Gansu, People's Republic of China.
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4
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Marques HM. The inorganic chemistry of the cobalt corrinoids - an update. J Inorg Biochem 2023; 242:112154. [PMID: 36871417 DOI: 10.1016/j.jinorgbio.2023.112154] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2023] [Revised: 01/23/2023] [Accepted: 01/26/2023] [Indexed: 02/05/2023]
Abstract
The inorganic chemistry of the cobalt corrinoids, derivatives of vitamin B12, is reviewed, with particular emphasis on equilibrium constants for, and kinetics of, their axial ligand substitution reactions. The role the corrin ligand plays in controlling and modifying the properties of the metal ion is emphasised. Other aspects of the chemistry of these compounds, including their structure, corrinoid complexes with metals other than cobalt, the redox chemistry of the cobalt corrinoids and their chemical redox reactions, and their photochemistry are discussed. Their role as catalysts in non-biological reactions and aspects of their organometallic chemistry are briefly mentioned. Particular mention is made of the role that computational methods - and especially DFT calculations - have played in developing our understanding of the inorganic chemistry of these compounds. A brief overview of the biological chemistry of the B12-dependent enzymes is also given for the reader's convenience.
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Affiliation(s)
- Helder M Marques
- Molecular Sciences Institute, School of Chemistry, University of the Witwatersrand, Johannesburg 2050, South Africa.
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5
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Kumar A, Yang X, Li J, Lewis JC. First and second sphere interactions accelerate non-native N-alkylation catalysis by the thermostable, methanol-tolerant B 12-dependent enzyme MtaC. Chem Commun (Camb) 2023; 59:4798-4801. [PMID: 37000588 PMCID: PMC10134074 DOI: 10.1039/d3cc01071f] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/01/2023]
Abstract
The corrinoid protein MtaC, which is natively involved in methyl transferase catalysis, catalyzes N-alkylation of aniline using ethyl diazoacetate. Our results show how the native preference of B12 scaffolds for radical versus polar chemistry translates to non-native catalysis, which could guide selection of B12-dependent proteins for biocatalysis. MtaC also has high thermal stability and organic solvent tolerance, remaining folded even in pure methanol.
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Affiliation(s)
- Amardeep Kumar
- Department of Chemistry, Indiana University, Bloomington, IN, 47405, USA.
| | - Xinhang Yang
- Department of Chemistry, Indiana University, Bloomington, IN, 47405, USA.
| | - Jianbin Li
- Department of Chemistry, Indiana University, Bloomington, IN, 47405, USA.
| | - Jared C Lewis
- Department of Chemistry, Indiana University, Bloomington, IN, 47405, USA.
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Abstract
Coabalamin-dependent O-demethylase in Blautia sp. strain MRG-PMF1 was found to catalyze the unprecedented allyl aryl ether cleavage reaction. To expand the potential biotechnological applications, the reaction mechanism of the allyl aryl ether C-O bond cleavage, proposed to utilize the reactive Co(I) supernucleophile species, was studied further from the anaerobic whole-cell biotransformation. Various allyl naphthyl ether derivatives were reacted with Blautia sp. MRG-PMF1 O-demethylase, and stereoisomers of allyl naphthyl ethers, including prenyl and but-2-enyl naphthyl ethers, were converted to the corresponding naphthol in a stereoselective manner. The allyl aryl ether cleavage reaction was regioselective, and 2-naphthyl ethers were converted faster than the corresponding 1-naphthyl ethers. However, MRG-PMF1 cocorrinoid O-demethylase was not able to convert (2-methylallyl) naphthyl ether substrates, and the conversion of propargyl naphthyl ether was extremely slow. From the results, it was proposed that the allyl ether cleavage reaction follows the nucleophilic conjugate substitution (SN2') mechanism. The reactivity and mechanism of the new allyl ether cleavage reaction by cobalamin-dependent O-demethylase would facilitate the application of Blautia sp. MRG-PMF1 O-demethylase in the area of green biotechnology. IMPORTANCE Biodegradation of environmental pollutants and valorization of biomaterials in a greener way is of great interest. Cobalamin-dependent O-demethylase in Blautia sp. MRG-PMF1 exclusively involves anaerobic C1 metabolism by cleaving the C-O bond of aromatic methoxy group and also produces various aryl alcohols by metabolizing allyl aryl ether compounds. Whereas methyl ether cleavage reaction is known to follow the SN2' mechanism, the reaction pattern and mechanism of the new allyl ether cleavage reaction by cobalamin-dependent O-demethylase have never been studied. For the first time, stereoselectivity and the SN2' mechanism of allyl aryl ether cleavage reaction by Blautia sp. MRG-PMF1 O-demethylase is reported, and the results would facilitate the application of Blautia sp. MRG-PMF1 O-demethylase in the area of green biotechnology.
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Müller M, Germer P, Andexer JN. Biocatalytic One-Carbon Transfer – A Review. SYNTHESIS-STUTTGART 2022. [DOI: 10.1055/s-0040-1719884] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/15/2022]
Abstract
AbstractThis review provides an overview of different C1 building blocks as substrates of enzymes, or part of their cofactors, and the resulting functionalized products. There is an emphasis on the broad range of possibilities of biocatalytic one-carbon extensions with C1 sources of different oxidation states. The identification of uncommon biosynthetic strategies, many of which might serve as templates for synthetic or biotechnological applications, towards one-carbon extensions is supported by recent genomic and metabolomic progress and hence we refer principally to literature spanning from 2014 to 2020.1 Introduction2 Methane, Methanol, and Methylamine3 Glycine4 Nitromethane5 SAM and SAM Ylide6 Other C1 Building Blocks7 Formaldehyde and Glyoxylate as Formaldehyde Equivalents8 Cyanide9 Formic Acid10 Formyl-CoA and Oxalyl-CoA11 Carbon Monoxide12 Carbon Dioxide13 Conclusions
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Padmanabhan S, Pérez-Castaño R, Osete-Alcaraz L, Polanco MC, Elías-Arnanz M. Vitamin B 12 photoreceptors. VITAMINS AND HORMONES 2022; 119:149-184. [PMID: 35337618 DOI: 10.1016/bs.vh.2022.01.007] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
Photoreceptor proteins enable living organisms to sense light and transduce this signal into biochemical outputs to elicit appropriate cellular responses. Their light sensing is typically mediated by covalently or noncovalently bound molecules called chromophores, which absorb light of specific wavelengths and modulate protein structure and biological activity. Known photoreceptors have been classified into about ten families based on the chromophore and its associated photosensory domain in the protein. One widespread photoreceptor family uses coenzyme B12 or 5'-deoxyadenosylcobalamin, a biological form of vitamin B12, to sense ultraviolet, blue, or green light, and its discovery revealed both a new type of photoreceptor and a novel functional facet of this vitamin, best known as an enzyme cofactor. Large strides have been made in our understanding of how these B12-based photoreceptors function, high-resolution structural descriptions of their functional states are available, as are details of their unusual photochemistry. Additionally, they have inspired notable applications in optogenetics/optobiochemistry and synthetic biology. Here, we provide an overview of what is currently known about these B12-based photoreceptors, their discovery, distribution, molecular mechanism of action, and the structural and photochemical basis of how they orchestrate signal transduction and gene regulation, and how they have been used to engineer optogenetic control of protein activities in living cells.
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Affiliation(s)
- S Padmanabhan
- Instituto de Química Física "Rocasolano", Consejo Superior de Investigaciones Científicas, Madrid, Spain.
| | - Ricardo Pérez-Castaño
- Departamento de Genética y Microbiología, Área de Genética (Unidad Asociada al IQFR-CSIC), Facultad de Biología, Universidad de Murcia, Murcia, Spain
| | - Lucía Osete-Alcaraz
- Departamento de Genética y Microbiología, Área de Genética (Unidad Asociada al IQFR-CSIC), Facultad de Biología, Universidad de Murcia, Murcia, Spain
| | - María Carmen Polanco
- Departamento de Genética y Microbiología, Área de Genética (Unidad Asociada al IQFR-CSIC), Facultad de Biología, Universidad de Murcia, Murcia, Spain
| | - Montserrat Elías-Arnanz
- Departamento de Genética y Microbiología, Área de Genética (Unidad Asociada al IQFR-CSIC), Facultad de Biología, Universidad de Murcia, Murcia, Spain.
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Yang X, Gerroll BHR, Jiang Y, Kumar A, Zubi YS, Baker LA, Lewis JC. Controlling Non-Native Cobalamin Reactivity and Catalysis in the Transcription Factor CarH. ACS Catal 2022; 12:935-942. [PMID: 35340760 DOI: 10.1021/acscatal.1c04748] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
Vitamin B12 derivatives catalyze a wide range of organic transformations, but B12-dependent enzymes are underutilized in biocatalysis relative to other metalloenzymes. In this study, we engineered a variant of the transcription factor CarH, called CarH*, that catalyzes styrene C-H alkylation with improved yields (2-6.5-fold) and selectivity relative to cobalamin. While the native function of CarH involves transcription regulation via adenosylcobalamin (AdoCbl) Co(III)-carbon bond cleavage and β-hydride elimination to generate 4',5'-didehydroadenosine, CarH*-catalyzed styrene alkylation proceeds via non-native oxidative addition and olefin addition coupled with a native-like β-hydride elimination. Mechanistic studies on this reaction echo findings from earlier studies on AdoCbl homolysis to suggest that CarH* selectivity results from its ability to impart a cage effect on radical intermediates. These findings lay the groundwork for the development of B12-dependent enzymes as catalysts for non-native transformations.
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Affiliation(s)
- Xinhang Yang
- Department of Chemistry, Indiana University, Bloomington, Indiana 47405, United States
| | | | - Yuhua Jiang
- Department of Chemistry, Indiana University, Bloomington, Indiana 47405, United States
| | - Amardeep Kumar
- Department of Chemistry, Indiana University, Bloomington, Indiana 47405, United States
| | - Yasmine S. Zubi
- Department of Chemistry, Indiana University, Bloomington, Indiana 47405, United States
| | - Lane A. Baker
- Department of Chemistry, Indiana University, Bloomington, Indiana 47405, United States
| | - Jared C. Lewis
- Department of Chemistry, Indiana University, Bloomington, Indiana 47405, United States
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Screening of Gas Substrate and Medium Effects on 2,3-Butanediol Production with C. ljungdahlii and C. autoethanogenum Aided by Improved Autotrophic Cultivation Technique. FERMENTATION 2021. [DOI: 10.3390/fermentation7040264] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
Gas fermentation by acetogens of the genus Clostridium is an attractive technology since it affords the production of biochemicals and biofuels from industrial waste gases while contributing to mitigate the carbon cycle alterations. The acetogenic model organisms C. ljungdahlii and C. autoethanogenum have already been used in large scale industrial fermentations. Among the natural products, ethanol production has already attained industrial scale. However, some acetogens are also natural producers of 2,3-butanediol (2,3-BDO), a platform chemical of relevant industrial interest. Here, we have developed a lab-scale screening campaign with the aim of enhancing 2,3-BDO production. Our study generated comparable data on growth and 2,3-BDO production of several batch gas fermentations using C. ljungdahlii and C. autoethanogenum grown on different gas substrates of primary applicative interest (CO2 · H2, CO · CO2, syngas) and on different media featuring different compositions as regards trace metals, mineral elements and vitamins. CO · CO2 fermentation was found to be preferable for the production of 2,3-BDO, and a fair comparison of the strains cultivated in comparable conditions revealed that C. ljungdahlii produced 3.43-fold higher titer of 2,3-BDO compared to C. autoethanogenum. Screening of different medium compositions revealed that mineral elements, Zinc and Iron exert a major positive influence on 2,3-BDO titer and productivity. Moreover, the CO2 influence on CO fermentation was explored by characterizing C. ljungdahlii response with respect to different gas ratios in the CO · CO2 gas mixtures. The screening strategies undertaken in this study led to the production of 2.03 ± 0.05 g/L of 2,3-BDO, which is unprecedented in serum bottle experiments.
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De Novo Cobalamin Biosynthesis, Transport, and Assimilation and Cobalamin-Mediated Regulation of Methionine Biosynthesis in Mycobacterium smegmatis. J Bacteriol 2021; 203:JB.00620-20. [PMID: 33468593 PMCID: PMC8088520 DOI: 10.1128/jb.00620-20] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2020] [Accepted: 01/08/2021] [Indexed: 02/07/2023] Open
Abstract
Alterations in cobalamin-dependent metabolism have marked the evolution of Mycobacterium tuberculosis into a human pathogen. However, the role(s) of cobalamin in mycobacterial physiology remain poorly understood. Cobalamin is an essential cofactor in all domains of life, yet its biosynthesis is restricted to some bacteria and archaea. Mycobacterium smegmatis, an environmental saprophyte frequently used as surrogate for the obligate human pathogen M. tuberculosis, carries approximately 30 genes predicted to be involved in de novo cobalamin biosynthesis. M. smegmatis also encodes multiple cobalamin-dependent enzymes, including MetH, a methionine synthase that catalyzes the final reaction in methionine biosynthesis. In addition to metH, M. smegmatis possesses a cobalamin-independent methionine synthase, metE, suggesting that enzyme use—MetH versus MetE—is regulated by cobalamin availability. Consistent with this notion, we previously described a cobalamin-sensing riboswitch controlling metE expression in M. tuberculosis. Here, we apply a targeted mass spectrometry-based approach to confirm de novo cobalamin biosynthesis in M. smegmatis during aerobic growth in vitro. We also demonstrate that M. smegmatis can transport and assimilate exogenous cyanocobalamin (CNCbl; also known as vitamin B12) and its precursor, dicyanocobinamide ([CN]2Cbi). However, the uptake of CNCbl and (CN)2Cbi in this organism is restricted and seems dependent on the conditional essentiality of the cobalamin-dependent methionine synthase. Using gene and protein expression analyses combined with single-cell growth kinetics and live-cell time-lapse microscopy, we show that transcription and translation of metE are strongly attenuated by endogenous cobalamin. These results support the inference that metH essentiality in M. smegmatis results from riboswitch-mediated repression of MetE expression. Moreover, differences observed in cobalamin-dependent metabolism between M. smegmatis and M. tuberculosis provide some insight into the selective pressures which might have shaped mycobacterial metabolism for pathogenicity. IMPORTANCE Alterations in cobalamin-dependent metabolism have marked the evolution of Mycobacterium tuberculosis into a human pathogen. However, the role(s) of cobalamin in mycobacterial physiology remains poorly understood. Using the nonpathogenic saprophyte M. smegmatis, we investigated the production of cobalamin, transport and assimilation of cobalamin precursors, and the role of cobalamin in regulating methionine biosynthesis. We confirm constitutive de novo cobalamin biosynthesis in M. smegmatis, in contrast with M. tuberculosis, which appears to lack de novo cobalamin biosynthetic capacity. We also show that uptake of cyanocobalamin (vitamin B12) and its precursors is restricted in M. smegmatis, apparently depending on the cofactor requirements of the cobalamin-dependent methionine synthase. These observations establish M. smegmatis as an informative foil to elucidate key metabolic adaptations enabling mycobacterial pathogenicity.
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Ward LC, McCue HV, Carnell AJ. Carboxyl Methyltransferases: Natural Functions and Potential Applications in Industrial Biotechnology. ChemCatChem 2020. [DOI: 10.1002/cctc.202001316] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Affiliation(s)
- Lucy C. Ward
- Department of Chemistry University of Liverpool Crown Street Liverpool L69 7ZD United Kingdom
| | - Hannah V. McCue
- GeneMill, Institute of Integrative Biology University of Liverpool Crown Street Liverpool L69 7ZB United Kingdom
| | - Andrew J. Carnell
- Department of Chemistry University of Liverpool Crown Street Liverpool L69 7ZD United Kingdom
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Huening KA, Jiang R, Krzycki JA. Kinetic and substrate complex characterization of RamA, a corrinoid protein reductive activase from Methanosarcina barkeri. FEMS Microbiol Lett 2020; 367:5896951. [PMID: 32840570 DOI: 10.1093/femsle/fnaa128] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2020] [Accepted: 07/27/2020] [Indexed: 12/30/2022] Open
Abstract
In microbial corrinoid-dependent methyltransferase systems, adventitious Co(I)-corrinoid oxidation halts catalysis and necessitates repair by ATP-dependent reductive activases. RamA, an activase with a C-terminal ferredoxin domain with two [4Fe-4S] clusters from methanogenic archaea, has been far less studied than the bacterial activases bearing an N-terminal ferredoxin domain with one [2Fe-2S] cluster. These differences suggest RamA might prove to have other distinctive characteristics. Here, we examine RamA kinetics and the stoichiometry of the corrinoid protein:RamA complex. Like bacterial activases, K+ stimulates RamA. Potassium stimulation had been questioned due to differences in the primary structure of bacterial and methanogen activases. Unlike one bacterial activase, ATP is not inhibitory allowing the first determination of apparent kinetic parameters for any corrinoid activase. Unlike bacterial activases, a single RamA monomer complexes a single corrinoid protein monomer. Alanine replacement of a RamA serine residue corresponding to the serine of one bacterial activase which ligates the corrinoid cobalt during complex formation led to only moderate changes in the kinetics of RamA. These results reveal new differences in the two types of corrinoid activases, and provide direct evidence for the proposal that corrinoid activases act as catalytic monomers, unlike other enzymes that couple ATP hydrolysis to difficult reductions.
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Affiliation(s)
- Katherine A Huening
- Department of Microbiology, The Ohio State University, Columbus, OH 43210, USA
| | - Ruisheng Jiang
- Department of Microbiology, The Ohio State University, Columbus, OH 43210, USA
| | - Joseph A Krzycki
- Department of Microbiology, The Ohio State University, Columbus, OH 43210, USA.,The Ohio State Biochemistry Program, The Ohio State University, Columbus, OH 43210, USA
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Danchin A, Sekowska A, You C. One-carbon metabolism, folate, zinc and translation. Microb Biotechnol 2020; 13:899-925. [PMID: 32153134 PMCID: PMC7264889 DOI: 10.1111/1751-7915.13550] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2020] [Accepted: 02/17/2020] [Indexed: 12/16/2022] Open
Abstract
The translation process, central to life, is tightly connected to the one-carbon (1-C) metabolism via a plethora of macromolecule modifications and specific effectors. Using manual genome annotations and putting together a variety of experimental studies, we explore here the possible reasons of this critical interaction, likely to have originated during the earliest steps of the birth of the first cells. Methionine, S-adenosylmethionine and tetrahydrofolate dominate this interaction. Yet, 1-C metabolism is unlikely to be a simple frozen accident of primaeval conditions. Reactive 1-C species (ROCS) are buffered by the translation machinery in a way tightly associated with the metabolism of iron-sulfur clusters, zinc and potassium availability, possibly coupling carbon metabolism to nitrogen metabolism. In this process, the highly modified position 34 of tRNA molecules plays a critical role. Overall, this metabolic integration may serve both as a protection against the deleterious formation of excess carbon under various growth transitions or environmental unbalanced conditions and as a regulator of zinc homeostasis, while regulating input of prosthetic groups into nascent proteins. This knowledge should be taken into account in metabolic engineering.
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Affiliation(s)
- Antoine Danchin
- AMAbiotics SASInstitut Cochin24 rue du Faubourg Saint‐Jacques75014ParisFrance
- School of Biomedical SciencesLi Ka Shing Faculty of MedicineThe University of Hong KongS.A.R. Hong KongChina
| | - Agnieszka Sekowska
- AMAbiotics SASInstitut Cochin24 rue du Faubourg Saint‐Jacques75014ParisFrance
| | - Conghui You
- Shenzhen Key Laboratory of Microbial Genetic EngineeringCollege of Life Sciences and OceanologyShenzhen University1066 Xueyuan Rd518055ShenzhenChina
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15
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Abstract
:In this review, we examined the possibility that some halogenated organic derivatives were used in the primitive ocean at the beginning of life on Earth. Firstly, we described the existence of extraterrestrial halogenated molecules, then we studied their nonbiological syntheses on the present Earth, especially in volcanic environments. In order to demonstrate the diversity of today’s halogenated biomolecules, representative examples are given and the biosynthesis of some of them is summarized. Finally, we proposed two aspects of the chemistry of halogenated compounds that may have been useful en route to biomolecules, firstly the use of methyl chloride as the first methylation reagent, secondly the synthesis and use of α-chloro-carbonyl derivatives.
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Affiliation(s)
- Sparta Youssef-Saliba
- Department of Molecular Chemistry, University Grenoble Alpes, CNRS, DCM, Campus, F-38058 Grenoble, France
| | - Yannick Vallée
- Department of Molecular Chemistry, University Grenoble Alpes, CNRS, DCM, Campus, F-38058 Grenoble, France
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16
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Godoy-Parejo C, Deng C, Zhang Y, Liu W, Chen G. Roles of vitamins in stem cells. Cell Mol Life Sci 2020; 77:1771-1791. [PMID: 31676963 PMCID: PMC11104807 DOI: 10.1007/s00018-019-03352-6] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2019] [Revised: 10/12/2019] [Accepted: 10/21/2019] [Indexed: 12/13/2022]
Abstract
Stem cells can differentiate to diverse cell types in our body, and they hold great promises in both basic research and clinical therapies. For specific stem cell types, distinctive nutritional and signaling components are required to maintain the proliferation capacity and differentiation potential in cell culture. Various vitamins play essential roles in stem cell culture to modulate cell survival, proliferation and differentiation. Besides their common nutritional functions, specific vitamins are recently shown to modulate signal transduction and epigenetics. In this article, we will first review classical vitamin functions in both somatic and stem cell cultures. We will then focus on how stem cells could be modulated by vitamins beyond their nutritional roles. We believe that a better understanding of vitamin functions will significantly benefit stem cell research, and help realize their potentials in regenerative medicine.
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Affiliation(s)
- Carlos Godoy-Parejo
- Centre of Reproduction, Development and Aging, Faculty of Health Sciences, University of Macau, Taipa, Macau SAR, China
| | - Chunhao Deng
- Centre of Reproduction, Development and Aging, Faculty of Health Sciences, University of Macau, Taipa, Macau SAR, China
| | - Yumeng Zhang
- Centre of Reproduction, Development and Aging, Faculty of Health Sciences, University of Macau, Taipa, Macau SAR, China
| | - Weiwei Liu
- Centre of Reproduction, Development and Aging, Faculty of Health Sciences, University of Macau, Taipa, Macau SAR, China
- Bioimaging and Stem Cell Core Facility, Faculty of Health Sciences, University of Macau, Taipa, Macau SAR, China
| | - Guokai Chen
- Centre of Reproduction, Development and Aging, Faculty of Health Sciences, University of Macau, Taipa, Macau SAR, China.
- Bioimaging and Stem Cell Core Facility, Faculty of Health Sciences, University of Macau, Taipa, Macau SAR, China.
- Institute of Translational Medicine, Faculty of Health Sciences, University of Macau, Taipa, Macau SAR, China.
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17
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Anaerobic bacteria need their vitamin B 12 to digest estrogen. Proc Natl Acad Sci U S A 2020; 117:1833-1835. [PMID: 31919281 DOI: 10.1073/pnas.1921340117] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023] Open
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18
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Retroconversion of estrogens into androgens by bacteria via a cobalamin-mediated methylation. Proc Natl Acad Sci U S A 2019; 117:1395-1403. [PMID: 31848239 DOI: 10.1073/pnas.1914380117] [Citation(s) in RCA: 35] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Steroid estrogens modulate physiology and development of vertebrates. Conversion of C19 androgens into C18 estrogens is thought to be an irreversible reaction. Here, we report a denitrifying Denitratisoma sp. strain DHT3 capable of catabolizing estrogens or androgens anaerobically. Strain DHT3 genome contains a polycistronic gene cluster, emtABCD, differentially transcribed under estrogen-fed conditions and predicted to encode a cobalamin-dependent methyltransferase system conserved among estrogen-utilizing anaerobes; an emtA-disrupted DHT3 derivative could catabolize androgens but not estrogens. These data, along with the observed androgen production in estrogen-fed strain DHT3 cultures, suggested the occurrence of a cobalamin-dependent estrogen methylation to form androgens. Consistently, the estrogen conversion into androgens in strain DHT3 cell extracts requires methylcobalamin and is inhibited by propyl iodide, a specific inhibitor of cobalamin-dependent enzymes. The identification of the cobalamin-dependent estrogen methylation thus represents an unprecedented metabolic link between cobalamin and steroid metabolism and suggests that retroconversion of estrogens into androgens occurs in the biosphere.
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19
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Jagtap AP, Kaltschnee L, Glöggler S. Hyperpolarization of 15N-pyridinium and 15N-aniline derivatives by using parahydrogen: new opportunities to store nuclear spin polarization in aqueous media. Chem Sci 2019; 10:8577-8582. [PMID: 31803432 PMCID: PMC6839503 DOI: 10.1039/c9sc02970b] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2019] [Accepted: 07/30/2019] [Indexed: 01/30/2023] Open
Abstract
Hyperpolarization techniques hold the promise to improve the sensitivity of magnetic resonance imaging (MRI) contrast agents by over 10 000-fold. Among these techniques, para-hydrogen induced polarization (PHIP) allows for generating contrast agents within seconds. Typical hyperpolarized contrast agents are traceable for 2-3 minutes only, thus prolonging tracking-times holds great importance for the development of new ways to diagnose and monitor diseases. Here, we report on the design of perdeuterated 15N-containing molecules with longitudinal relaxation times (T 1) of several minutes. T 1 is a measure for how long hyperpolarization can be stored. In particular, we introduce two new hyperpolarizable families of compounds that we signal enhanced with para-hydrogen: tert-amine aniline derivatives and a quaternary pyridinium compound with 15N-T 1 of about 8 minutes. Especially the latter compound has great potential for applicability since we achieved 15N-polarization up to 8% and the pyridinium motif is contained in a variety of drug molecules and is also used in drug delivery systems.
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Affiliation(s)
- Anil P Jagtap
- Max-Planck-Institute for Biophysical Chemistry , Am Fassberg 11 , 37077 Göttingen , Germany .
- Center for Biostructural Imaging of Neurodegeneration , Von-Siebold-Str. 3a , 37075 Göttingen , Germany
| | - Lukas Kaltschnee
- Max-Planck-Institute for Biophysical Chemistry , Am Fassberg 11 , 37077 Göttingen , Germany .
- Center for Biostructural Imaging of Neurodegeneration , Von-Siebold-Str. 3a , 37075 Göttingen , Germany
| | - Stefan Glöggler
- Max-Planck-Institute for Biophysical Chemistry , Am Fassberg 11 , 37077 Göttingen , Germany .
- Center for Biostructural Imaging of Neurodegeneration , Von-Siebold-Str. 3a , 37075 Göttingen , Germany
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20
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Elucidating the mechanism of cob(I)alamin mediated methylation reactions by alkyl halides: SN2 or radical mechanism? J Catal 2019. [DOI: 10.1016/j.jcat.2019.06.036] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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21
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Farnberger J, Hiebler K, Bierbaumer S, Skibar W, Zepeck F, Kroutil W. Cobalamin-Dependent Apparent Intramolecular Methyl Transfer for Biocatalytic Constitutional Isomerization of Catechol Monomethyl Ethers. ACS Catal 2019; 9:3900-3905. [PMID: 31080689 PMCID: PMC6503581 DOI: 10.1021/acscatal.8b05072] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2018] [Revised: 03/14/2019] [Indexed: 12/29/2022]
Abstract
Isomerization is a fundamental reaction in chemistry. However, isomerization of phenyl methyl ethers has not been described yet. Using a cobalamin-dependent methyl transferase, a reversible shuttle concept was investigated for isomerization of catechol monomethyl ethers. The methyl ether of substituted catechol derivatives was successfully transferred onto the adjacent hydroxy moiety. For instance, the cobalamin-dependent biocatalyst transformed isovanillin to its regioisomer vanillin with significant regioisomeric excess (68% vanillin). To the best of our knowledge, isomerization by methyl transfer employing a methyl transferase has not been reported before.
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Affiliation(s)
- Judith
E. Farnberger
- Austrian
Centre of Industrial Biotechnolgy, ACIB GmbH, c/o University of Graz, Heinrichstrasse 28, 8010 Graz, Austria
| | - Katharina Hiebler
- Institute
of Chemistry, Organic and Bioorganic Chemistry, NAWI Graz, BioTechMed
Graz, University of Graz, Heinrichstrasse 28, 8010 Graz, Austria
| | - Sarah Bierbaumer
- Institute
of Chemistry, Organic and Bioorganic Chemistry, NAWI Graz, BioTechMed
Graz, University of Graz, Heinrichstrasse 28, 8010 Graz, Austria
| | - Wolfgang Skibar
- Sandoz
GmbH, Biocatalysis Lab, Biochemiestrasse 10, 6250 Kundl, Austria
| | - Ferdinand Zepeck
- Sandoz
GmbH, Biocatalysis Lab, Biochemiestrasse 10, 6250 Kundl, Austria
| | - Wolfgang Kroutil
- Institute
of Chemistry, Organic and Bioorganic Chemistry, NAWI Graz, BioTechMed
Graz, University of Graz, Heinrichstrasse 28, 8010 Graz, Austria
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22
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Regnell O, Watras CJ. Microbial Mercury Methylation in Aquatic Environments: A Critical Review of Published Field and Laboratory Studies. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2019; 53:4-19. [PMID: 30525497 DOI: 10.1021/acs.est.8b02709] [Citation(s) in RCA: 103] [Impact Index Per Article: 20.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/21/2023]
Abstract
Methylmercury (MeHg) is an environmental contaminant of concern because it biomagnifies in aquatic food webs and poses a health hazard to aquatic biota, piscivorous wildlife and humans. The dominant source of MeHg to freshwater systems is the methylation of inorganic Hg (IHg) by anaerobic microorganisms; and it is widely agreed that in situ rates of Hg methylation depend on two general factors: the activity of Hg methylators and their uptake of IHg. A large body of research has focused on the biogeochemical processes that regulate these two factors in nature; and studies conducted within the past ten years have made substantial progress in identifying the genetic basis for intracellular methylation and defining the processes that govern the cellular uptake of IHg. Current evidence indicates that all Hg methylating anaerobes possess the gene pair hgcAB that encodes proteins essential for Hg methylation. These genes are found in a large variety of anaerobes, including iron reducers and methanogens; but sulfate reduction is the metabolic process most often reported to show strong links to MeHg production. The uptake of Hg substrate prior to methylation may occur by passive or active transport, or by a combination of both. Competitive inhibition of Hg uptake by Zn speaks in favor of active transport and suggests that essential metal transporters are involved. Shortly after its formation, MeHg is typically released from cells, but the efflux mechanisms are unknown. Although methylation facilitates Hg depuration from the cell, evidence suggests that the hgcAB genes are not induced or favored by Hg contamination. Instead, high MeHg production can be linked to high Hg bioavailability as a result of the formation of Hg(SH)2, HgS nanoparticles, and Hg-thiol complexes. It is also possible that sulfidic conditions require strong essential metal uptake systems that inadvertently bring Hg into the cytoplasm of Hg methylating microbes. In comparison with freshwaters, Hg methylation in open ocean waters appears less restricted to anoxic environments. It does seem to occur mainly in oxygen deficient zones (ODZs), and possibly within anaerobic microzones of settling organic matter, but MeHg (CH3Hg+) and Me2Hg ((CH3)2Hg) have been shown to form also in surface water samples from the euphotic zone. Future studies may disclose whether several different pathways lead to Hg methylation in marine waters and explain why Me2Hg is a significant Hg species in oceans but seemingly not in most freshwaters.
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Affiliation(s)
- Olof Regnell
- Department of Biology/Aquatic Ecology , Lund University , SE-223 62 Lund , Sweden
| | - Carl J Watras
- Bureau of Water Quality , Wisconsin Department of Natural Resources , Madison , Wisconsin 53703 , United States
- Center for Limnology , University of Wisconsin-Madison , 3110 Trout Lake Station Drive , Boulder Junction , Wisconsin 54512 , United States
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23
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Farnberger JE, Richter N, Hiebler K, Bierbaumer S, Pickl M, Skibar W, Zepeck F, Kroutil W. Biocatalytic methylation and demethylation via a shuttle catalysis concept involving corrinoid proteins. Commun Chem 2018. [DOI: 10.1038/s42004-018-0083-2] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
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24
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Yogavel M, Nettleship JE, Sharma A, Harlos K, Jamwal A, Chaturvedi R, Sharma M, Jain V, Chhibber-Goel J, Sharma A. Structure of 6-hydroxymethyl-7,8-dihydropterin pyrophosphokinase-dihydropteroate synthase from Plasmodium vivax sheds light on drug resistance. J Biol Chem 2018; 293:14962-14972. [PMID: 30104413 DOI: 10.1074/jbc.ra118.004558] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2018] [Revised: 08/08/2018] [Indexed: 11/06/2022] Open
Abstract
The genomes of the malaria-causing Plasmodium parasites encode a protein fused of 6-hydroxymethyl-7,8-dihydropterin pyrophosphokinase (HPPK) and dihydropteroate synthase (DHPS) domains that catalyze sequential reactions in the folate biosynthetic pathway. Whereas higher organisms derive folate from their diet and lack the enzymes for its synthesis, most eubacteria and a number of lower eukaryotes including malaria parasites synthesize tetrahydrofolate via DHPS. Plasmodium falciparum (Pf) and Plasmodium vivax (Pv) HPPK-DHPSs are currently targets of drugs like sulfadoxine (SDX). The SDX effectiveness as an antimalarial drug is increasingly diminished by the rise and spread of drug-resistant mutations. Here, we present the crystal structure of PvHPPK-DHPS in complex with four substrates/analogs, revealing the bifunctional PvHPPK-DHPS architecture in an unprecedented state of enzymatic activation. SDX's effect on HPPK-DHPS is due to 4-amino benzoic acid (pABA) mimicry, and the PvHPPK-DHPS structure sheds light on the SDX-binding cavity, as well as on mutations that effect SDX potency. We mapped five dominant drug resistance mutations in PvHPPK-DHPS: S382A, A383G, K512E/D, A553G, and V585A, most of which occur individually or in clusters proximal to the pABA-binding site. We found that these resistance mutations subtly alter the intricate enzyme/pABA/SDX interactions such that DHPS affinity for pABA is diminished only moderately, but its affinity for SDX is changed substantially. In conclusion, the PvHPPK-DHPS structure rationalizes and unravels the structural bases for SDX resistance mutations and highlights architectural features in HPPK-DHPSs from malaria parasites that can form the basis for developing next-generation anti-folate agents to combat malaria parasites.
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Affiliation(s)
- Manickam Yogavel
- From the Molecular Medicine-Structural Parasitology Group, International Centre for Genetic Engineering and Biotechnology, New Delhi 110067, India,
| | - Joanne E Nettleship
- the Division of Structural Biology, Wellcome Centre for Human Genetics, University of Oxford, Oxford OX3 7BN, United Kingdom, and.,the Oxford Protein Production Facility, United Kingdom Research Complex at Harwell, Rutherford Appleton Laboratory, Oxford OX11 0FA, United Kingdom
| | - Akansha Sharma
- From the Molecular Medicine-Structural Parasitology Group, International Centre for Genetic Engineering and Biotechnology, New Delhi 110067, India
| | - Karl Harlos
- the Division of Structural Biology, Wellcome Centre for Human Genetics, University of Oxford, Oxford OX3 7BN, United Kingdom, and
| | - Abhishek Jamwal
- From the Molecular Medicine-Structural Parasitology Group, International Centre for Genetic Engineering and Biotechnology, New Delhi 110067, India
| | - Rini Chaturvedi
- From the Molecular Medicine-Structural Parasitology Group, International Centre for Genetic Engineering and Biotechnology, New Delhi 110067, India
| | - Manmohan Sharma
- From the Molecular Medicine-Structural Parasitology Group, International Centre for Genetic Engineering and Biotechnology, New Delhi 110067, India
| | - Vitul Jain
- the Division of Structural Biology, Wellcome Centre for Human Genetics, University of Oxford, Oxford OX3 7BN, United Kingdom, and
| | - Jyoti Chhibber-Goel
- From the Molecular Medicine-Structural Parasitology Group, International Centre for Genetic Engineering and Biotechnology, New Delhi 110067, India
| | - Amit Sharma
- From the Molecular Medicine-Structural Parasitology Group, International Centre for Genetic Engineering and Biotechnology, New Delhi 110067, India
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25
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Abstract
The biosynthesis of B12, involving up to 30 different enzyme-mediated steps, only occurs in bacteria. Thus, most eukaryotes require an external source of B12, and yet the vitamin appears to have only two functions in eukaryotes: as a cofactor for the enzymes methionine synthase and methylmalonylCoA mutase. These two functions are crucial for normal health in humans, and in particular, the formation of methionine is essential for providing methyl groups for over 100 methylation processes. Interference with the methionine synthase reaction not only depletes the body of methyl groups but also leads to the accumulation of homocysteine, a risk factor for many diseases. The syndrome pernicious anemia, characterized by lack of intrinsic factor, leads to a severe, sometimes fatal form of B12 deficiency. However, there is no sharp cutoff for B12 deficiency; rather, there is a continuous inverse relationship between serum B12 and a variety of undesirable outcomes, including neural tube defects, stroke, and dementia. The brain is particularly vulnerable; in children, inadequate B12 stunts brain and intellectual development. Suboptimal B12 status (serum B12<300pmol/L) is very common, occurring in 30%-60% of the population, in particular in pregnant women and in less-developed countries. Thus, many tens of millions of people in the world may suffer harm from having a poor B12 status. Public health steps are urgently needed to correct this inadequacy.
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Affiliation(s)
- A David Smith
- Department of Pharmacology, University of Oxford, Oxford, United Kingdom.
| | - Martin J Warren
- School of Biosciences, University of Kent, Canterbury, Kent, United Kingdom
| | - Helga Refsum
- Department of Nutrition, University of Oslo, Oslo, Norway
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26
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Jiang H, Qin Y, Gadow SI, Ohnishi A, Fujimoto N, Li YY. Bio-hythane production from cassava residue by two-stage fermentative process with recirculation. BIORESOURCE TECHNOLOGY 2018; 247:769-775. [PMID: 30060412 DOI: 10.1016/j.biortech.2017.09.102] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/30/2017] [Revised: 09/14/2017] [Accepted: 09/15/2017] [Indexed: 06/08/2023]
Abstract
The two-stage hythane fermentation of cassava residue low in protein, rich in iron, and deficient in nickel and cobalt, resulted in failure after long-term operation, showing a radical decrease in methane production along with an increase in volatile fatty acids (VFAs) accumulation in the second stage. Based on the gap between theoretical demand and existing content of nutrients, the effect of their additions on hythane fermentation was validated in the repeated batch experiment and continuous experiment. The proliferation of hydrolysis bacteria, acidogens, and hydrogen producing bacteria and methanogens was guaranteed by sufficient N (0.7g/L), S (30mg/L), Ni (1.0mg/L), and Co (1.0mg/L), and the metabolism of a sustainable hythane fermentation was recovered. In this optimal nutrient combination of above trace elements, the highest hythane yield (426m3 hythane with 27.7% of hydrogen from 1ton of cassava residue) was obtained.
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Affiliation(s)
- Hongyu Jiang
- Department of Fermentation Science, Faculty of Applied Bio-science, Tokyo University of Agriculture, 1-1-1 Sakuragaoka, Setagaya-ku, Tokyo 1568502, Japan
| | - Yu Qin
- Department of Civil and Environmental Engineering, Graduate School of Engineering, Tohoku University, 6-6-06 Aza-Aoba, Aramaki, Aoba-ku, Sendai, Miyagi 980-8579, Japan
| | - S I Gadow
- Department of Agricultural Microbiology, Agriculture and Biology Research Division, National Research Centre, 33 EI Buhouth St., Dokki, Cairo 12622, Egypt
| | - Akihiro Ohnishi
- Department of Fermentation Science, Faculty of Applied Bio-science, Tokyo University of Agriculture, 1-1-1 Sakuragaoka, Setagaya-ku, Tokyo 1568502, Japan
| | - Naoshi Fujimoto
- Department of Fermentation Science, Faculty of Applied Bio-science, Tokyo University of Agriculture, 1-1-1 Sakuragaoka, Setagaya-ku, Tokyo 1568502, Japan
| | - Yu-You Li
- Department of Civil and Environmental Engineering, Graduate School of Engineering, Tohoku University, 6-6-06 Aza-Aoba, Aramaki, Aoba-ku, Sendai, Miyagi 980-8579, Japan.
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27
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Schubert T. The organohalide-respiring bacterium Sulfurospirillum multivorans: a natural source for unusual cobamides. World J Microbiol Biotechnol 2017; 33:93. [DOI: 10.1007/s11274-017-2258-x] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2017] [Accepted: 04/01/2017] [Indexed: 01/27/2023]
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28
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Qian C, Johs A, Chen H, Mann BF, Lu X, Abraham PE, Hettich RL, Gu B. Global Proteome Response to Deletion of Genes Related to Mercury Methylation and Dissimilatory Metal Reduction Reveals Changes in Respiratory Metabolism in Geobacter sulfurreducens PCA. J Proteome Res 2016; 15:3540-3549. [PMID: 27463218 DOI: 10.1021/acs.jproteome.6b00263] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Geobacter sulfurreducens PCA can reduce, sorb, and methylate mercury (Hg); however, the underlying biochemical mechanisms of these processes and interdependent metabolic pathways remain unknown. In this study, shotgun proteomics was used to compare global proteome profiles between wild-type G. sulfurreducens PCA and two mutant strains: a ΔhgcAB mutant, which is deficient in two genes known to be essential for Hg methylation and a ΔomcBESTZ mutant, which is deficient in five outer membrane c-type cytochromes and thus impaired in its ability for dissimilatory metal ion reduction. We were able to delineate the global response of G. sulfurreducens PCA in both mutants and identify cellular networks and metabolic pathways that were affected by the loss of these genes. Deletion of hgcAB increased the relative abundances of proteins implicated in extracellular electron transfer, including most of the c-type cytochromes, PilA-C, and OmpB, and is consistent with a previously observed increase in Hg reduction in the ΔhgcAB mutant. Deletion of omcBESTZ was found to significantly increase relative abundances of various methyltransferases, suggesting that a loss of dissimilatory reduction capacity results in elevated activity among one-carbon (C1) metabolic pathways and thus increased methylation. We show that G. sulfurreducens PCA encodes only the folate branch of the acetyl-CoA pathway, and proteins associated with the folate branch were found at lower abundance in the ΔhgcAB mutant strain than the wild type. This observation supports the hypothesis that the function of HgcA and HgcB is linked to C1 metabolism through the folate branch of the acetyl-CoA pathway by providing methyl groups required for Hg methylation.
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Affiliation(s)
- Chen Qian
- Chemical Sciences Division, Oak Ridge National Laboratory , Oak Ridge, Tennessee 37831, United States.,Graduate School of Genome Science and Technology, University of Tennessee , Knoxville, Tennessee 37996, United States
| | - Alexander Johs
- Environmental Sciences Division, Oak Ridge National Laboratory , Oak Ridge, Tennessee 37831, United States
| | - Hongmei Chen
- Environmental Sciences Division, Oak Ridge National Laboratory , Oak Ridge, Tennessee 37831, United States
| | - Benjamin F Mann
- Environmental Sciences Division, Oak Ridge National Laboratory , Oak Ridge, Tennessee 37831, United States
| | - Xia Lu
- Environmental Sciences Division, Oak Ridge National Laboratory , Oak Ridge, Tennessee 37831, United States
| | - Paul E Abraham
- Chemical Sciences Division, Oak Ridge National Laboratory , Oak Ridge, Tennessee 37831, United States
| | - Robert L Hettich
- Chemical Sciences Division, Oak Ridge National Laboratory , Oak Ridge, Tennessee 37831, United States.,Graduate School of Genome Science and Technology, University of Tennessee , Knoxville, Tennessee 37996, United States
| | - Baohua Gu
- Environmental Sciences Division, Oak Ridge National Laboratory , Oak Ridge, Tennessee 37831, United States
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29
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Thomas CM, Saulnier DMA, Spinler JK, Hemarajata P, Gao C, Jones SE, Grimm A, Balderas MA, Burstein MD, Morra C, Roeth D, Kalkum M, Versalovic J. FolC2-mediated folate metabolism contributes to suppression of inflammation by probiotic Lactobacillus reuteri. Microbiologyopen 2016; 5:802-818. [PMID: 27353144 PMCID: PMC5061717 DOI: 10.1002/mbo3.371] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/25/2015] [Revised: 03/20/2016] [Accepted: 03/30/2016] [Indexed: 12/16/2022] Open
Abstract
Bacterial‐derived compounds from the intestinal microbiome modulate host mucosal immunity. Identification and mechanistic studies of these compounds provide insights into host–microbial mutualism. Specific Lactobacillus reuteri strains suppress production of the proinflammatory cytokine, tumor necrosis factor (TNF), and are protective in a mouse model of colitis. Human‐derived L. reuteri strain ATCC PTA 6475 suppresses intestinal inflammation and produces 5,10‐methenyltetrahydrofolic acid polyglutamates. Insertional mutagenesis identified the bifunctional dihydrofolate synthase/folylpolyglutamate synthase type 2 (folC2) gene as essential for 5,10‐methenyltetrahydrofolic acid polyglutamate biosynthesis, as well as for suppression of TNF production by activated human monocytes, and for the anti‐inflammatory effect of L. reuteri 6475 in a trinitrobenzene sulfonic acid‐induced mouse model of acute colitis. In contrast, folC encodes the enzyme responsible for folate polyglutamylation but does not impact TNF suppression by L. reuteri. Comparative transcriptomics between wild‐type and mutant L. reuteri strains revealed additional genes involved in immunomodulation, including previously identified hdc genes involved in histidine to histamine conversion. The folC2 mutant yielded diminished hdc gene cluster expression and diminished histamine production, suggesting a link between folate and histadine/histamine metabolism. The identification of genes and gene networks regulating production of bacterial‐derived immunoregulatory molecules may lead to improved anti‐inflammatory strategies for digestive diseases.
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Affiliation(s)
- Carissa M Thomas
- Integrative Molecular and Biomedical Sciences (IMBS), Baylor College of Medicine, One Baylor Plaza, Houston, Texas, 77030
| | - Delphine M A Saulnier
- Department of Pathology & Immunology, Baylor College of Medicine, Houston, Texas.,Department of Pathology, Texas Children's Hospital, 1102 Bates Ave, Houston, Texas, 77030
| | - Jennifer K Spinler
- Department of Pathology & Immunology, Baylor College of Medicine, Houston, Texas.,Department of Pathology, Texas Children's Hospital, 1102 Bates Ave, Houston, Texas, 77030
| | - Peera Hemarajata
- Department of Molecular Virology and Microbiology, Baylor College of Medicine, Houston, Texas
| | - Chunxu Gao
- Department of Pathology & Immunology, Baylor College of Medicine, Houston, Texas.,Department of Pathology, Texas Children's Hospital, 1102 Bates Ave, Houston, Texas, 77030
| | - Sara E Jones
- Integrative Molecular and Biomedical Sciences (IMBS), Baylor College of Medicine, One Baylor Plaza, Houston, Texas, 77030
| | - Ashley Grimm
- Department of Pathology & Immunology, Baylor College of Medicine, Houston, Texas.,Department of Pathology, Texas Children's Hospital, 1102 Bates Ave, Houston, Texas, 77030
| | - Miriam A Balderas
- Department of Pathology & Immunology, Baylor College of Medicine, Houston, Texas.,Department of Pathology, Texas Children's Hospital, 1102 Bates Ave, Houston, Texas, 77030
| | - Matthew D Burstein
- Structural and Computational Biology and Molecular Biophysics Graduate Program, Baylor College of Medicine, Houston, Texas
| | - Christina Morra
- Integrative Molecular and Biomedical Sciences (IMBS), Baylor College of Medicine, One Baylor Plaza, Houston, Texas, 77030.,Department of Pathology, Texas Children's Hospital, 1102 Bates Ave, Houston, Texas, 77030
| | - Daniel Roeth
- Department of Molecular Immunology, Beckman Research Institute of the City of Hope, 1500 E Duarte Rd., Duarte, California, 91010
| | - Markus Kalkum
- Department of Molecular Immunology, Beckman Research Institute of the City of Hope, 1500 E Duarte Rd., Duarte, California, 91010
| | - James Versalovic
- Department of Pathology & Immunology, Baylor College of Medicine, Houston, Texas. .,Department of Pathology, Texas Children's Hospital, 1102 Bates Ave, Houston, Texas, 77030.
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Ding W, Li Q, Jia Y, Ji X, Qianzhu H, Zhang Q. Emerging Diversity of the Cobalamin-Dependent Methyltransferases Involving Radical-Based Mechanisms. Chembiochem 2016; 17:1191-7. [PMID: 27028019 DOI: 10.1002/cbic.201600107] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2016] [Indexed: 11/10/2022]
Abstract
Cobalamins comprise a group of cobalt-containing organometallic cofactors that play important roles in cellular metabolism. Although many cobalamin-dependent methyltransferases (e.g., methionine synthase MetH) have been extensively studied, a new group of methyltransferases that are cobalamin-dependent and utilize radical chemistry in catalysis is just beginning to be appreciated. In this Concept article, we summarize recent advances in the understanding of the radical-based and cobalamin-dependent methyltransferases and discuss the functional and mechanistic diversity of this emerging class of enzymes.
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Affiliation(s)
- Wei Ding
- Key Laboratory of Cell Activities and Stress Adaptations, (Ministry of Education), School of Life Sciences, Lanzhou University, Lanzhou, 730000, China.,Department of Chemistry, Fudan University, Shanghai, 200433, China
| | - Qien Li
- Key Laboratory of Cell Activities and Stress Adaptations, (Ministry of Education), School of Life Sciences, Lanzhou University, Lanzhou, 730000, China
| | - Youli Jia
- Key Laboratory of Cell Activities and Stress Adaptations, (Ministry of Education), School of Life Sciences, Lanzhou University, Lanzhou, 730000, China.,Department of Chemistry, Fudan University, Shanghai, 200433, China
| | - Xinjian Ji
- Department of Chemistry, Fudan University, Shanghai, 200433, China
| | - Haocheng Qianzhu
- Department of Chemistry, Fudan University, Shanghai, 200433, China
| | - Qi Zhang
- Department of Chemistry, Fudan University, Shanghai, 200433, China.
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Sjuts H, Dunstan MS, Fisher K, Leys D. Structures of the methyltransferase component of Desulfitobacterium hafniense DCB-2 O-demethylase shed light on methyltetrahydrofolate formation. ACTA ACUST UNITED AC 2015; 71:1900-8. [PMID: 26327380 DOI: 10.1107/s1399004715013061] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2015] [Accepted: 07/07/2015] [Indexed: 11/10/2022]
Abstract
O-Demethylation by acetogenic or organohalide-respiring bacteria leads to the formation of methyltetrahydrofolate from aromatic methyl ethers. O-Demethylases, which are cobalamin-dependent, three-component enzyme systems, catalyse methyl-group transfers from aromatic methyl ethers to tetrahydrofolate via methylcobalamin intermediates. In this study, crystal structures of the tetrahydrofolate-binding methyltransferase module from a Desulfitobacterium hafniense DCB-2 O-demethylase were determined both in complex with tetrahydrofolate and the product methyltetrahydrofolate. While these structures are similar to previously determined methyltransferase structures, the position of key active-site residues is subtly altered. A strictly conserved Asn is displaced to establish a putative proton-transfer network between the substrate N5 and solvent. It is proposed that this supports the efficient catalysis of methyltetrahydrofolate formation, which is necessary for efficient O-demethylation.
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Affiliation(s)
- Hanno Sjuts
- Manchester Institute of Biotechnology, Faculty of Life Sciences, University of Manchester, 131 Princess Street, Manchester M1 7DN, England
| | - Mark S Dunstan
- Manchester Institute of Biotechnology, Faculty of Life Sciences, University of Manchester, 131 Princess Street, Manchester M1 7DN, England
| | - Karl Fisher
- Manchester Institute of Biotechnology, Faculty of Life Sciences, University of Manchester, 131 Princess Street, Manchester M1 7DN, England
| | - David Leys
- Manchester Institute of Biotechnology, Faculty of Life Sciences, University of Manchester, 131 Princess Street, Manchester M1 7DN, England
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Yin S, Jiang H, Chen D, Murchie AIH. Substrate recognition and modification by the nosiheptide resistance methyltransferase. PLoS One 2015; 10:e0122972. [PMID: 25910005 PMCID: PMC4409310 DOI: 10.1371/journal.pone.0122972] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2015] [Accepted: 02/11/2015] [Indexed: 11/29/2022] Open
Abstract
Background The proliferation of antibiotic resistant pathogens is an increasing threat to the general public. Resistance may be conferred by a number of mechanisms including covalent or mutational modification of the antibiotic binding site, covalent modification of the drug, or the over-expression of efflux pumps. The nosiheptide resistance methyltransferase (NHR) confers resistance to the thiazole antibiotic nosiheptide in the nosiheptide producer organism Streptomyces actuosus through 2ʹO-methylation of 23S rRNA at the nucleotide A1067. Although the crystal structures of NHR and the closely related thiostrepton-resistance methyltransferase (TSR) in complex with the cofactor S-Adenosyl-L-methionine (SAM) are available, the principles behind NHR substrate recognition and catalysis remain unclear. Methodology/Principal Findings We have analyzed the binding interactions between NHR and model 58 and 29 nucleotide substrate RNAs by gel electrophoresis mobility shift assays (EMSA) and fluorescence anisotropy. We show that the enzyme binds to RNA as a dimer. By constructing a hetero-dimer complex composed of one wild-type subunit and one inactive mutant NHR-R135A subunit, we show that only one functional subunit of the NHR homodimer is required for its enzymatic activity. Mutational analysis suggests that the interactions between neighbouring bases (G1068 and U1066) and A1067 have an important role in methyltransfer activity, such that the substitution of a deoxy sugar spacer (5ʹ) to the target nucleotide achieved near wild-type levels of methylation. A series of atomic substitutions at specific positions on the substrate adenine show that local base-base interactions between neighbouring bases are important for methylation. Conclusion/Significance Taken together these data suggest that local base-base interactions play an important role in aligning the substrate 2’ hydroxyl group of A1067 for methyl group transfer. Methylation of nucleic acids is playing an increasingly important role in fundamental biological processes and we anticipate that the approach outlined in this manuscript may be useful for investigating other classes of nucleic acid methyltransferases.
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Affiliation(s)
- Sitao Yin
- Key Laboratory of Molecular Medicine, the Ministry of Education, Department of Biochemistry and Molecular Biology, Fudan University Shanghai Medical College, Shanghai 200032, PR China
- Institutes of Biomedical Sciences, Fudan University Shanghai Medical College, Shanghai 200032, PR China
| | - Hengyi Jiang
- Key Laboratory of Molecular Medicine, the Ministry of Education, Department of Biochemistry and Molecular Biology, Fudan University Shanghai Medical College, Shanghai 200032, PR China
- Institutes of Biomedical Sciences, Fudan University Shanghai Medical College, Shanghai 200032, PR China
| | - Dongrong Chen
- Key Laboratory of Molecular Medicine, the Ministry of Education, Department of Biochemistry and Molecular Biology, Fudan University Shanghai Medical College, Shanghai 200032, PR China
- Institutes of Biomedical Sciences, Fudan University Shanghai Medical College, Shanghai 200032, PR China
- * E-mail: (AM); (DC)
| | - Alastair I. H. Murchie
- Key Laboratory of Molecular Medicine, the Ministry of Education, Department of Biochemistry and Molecular Biology, Fudan University Shanghai Medical College, Shanghai 200032, PR China
- Institutes of Biomedical Sciences, Fudan University Shanghai Medical College, Shanghai 200032, PR China
- * E-mail: (AM); (DC)
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Site-directed mutagenesis of HgcA and HgcB reveals amino acid residues important for mercury methylation. Appl Environ Microbiol 2015; 81:3205-17. [PMID: 25724962 DOI: 10.1128/aem.00217-15] [Citation(s) in RCA: 57] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2015] [Accepted: 02/24/2015] [Indexed: 11/20/2022] Open
Abstract
Methylmercury is a potent neurotoxin that is produced by anaerobic microorganisms from inorganic mercury by a recently discovered pathway. A two-gene cluster, consisting of hgcA and hgcB, encodes two of the proteins essential for this activity. hgcA encodes a corrinoid protein with a strictly conserved cysteine proposed to be the ligand for cobalt in the corrinoid cofactor, whereas hgcB encodes a ferredoxin-like protein thought to be an electron donor to HgcA. Deletion of either gene eliminates mercury methylation by the methylator Desulfovibrio desulfuricans ND132. Here, site-directed mutants of HgcA and HgcB were constructed to determine amino acid residues essential for mercury methylation. Mutations of the strictly conserved residue Cys93 in HgcA, the proposed ligand for the corrinoid cobalt, to Ala or Thr completely abolished the methylation capacity, but a His substitution produced measurable methylmercury. Mutations of conserved amino acids near Cys93 had various impacts on the methylation capacity but showed that the structure of the putative "cap helix" region harboring Cys93 is crucial for methylation function. In the ferredoxin-like protein HgcB, only one of two conserved cysteines found at the C terminus was necessary for methylation, but either cysteine sufficed. An additional, strictly conserved cysteine, Cys73, was also determined to be essential for methylation. This study supports the previously predicted importance of Cys93 in HgcA for methylation of mercury and reveals additional residues in HgcA and HgcB that facilitate the production of this neurotoxin.
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Ubhi DK, Robertus JD. The Cobalamin-Independent Methionine Synthase Enzyme Captured in a Substrate-Induced Closed Conformation. J Mol Biol 2015; 427:901-909. [DOI: 10.1016/j.jmb.2014.12.014] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2014] [Revised: 12/19/2014] [Accepted: 12/21/2014] [Indexed: 10/24/2022]
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Chandra V, Hong KM. Effects of deranged metabolism on epigenetic changes in cancer. Arch Pharm Res 2015; 38:321-37. [PMID: 25628247 DOI: 10.1007/s12272-015-0561-3] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2014] [Accepted: 01/09/2015] [Indexed: 12/17/2022]
Abstract
The concept of epigenetics is now providing the mechanisms by which cells transfer their new environmental-change-induced phenotypes to their daughter cells. However, how extracellular or cytoplasmic environmental cues are connected to the nuclear epigenome remains incompletely understood. Recently emerging evidence suggests that epigenetic changes are correlated with metabolic changes via chromatin remodeling. As many human complex diseases including cancer harbor both epigenetic changes and metabolic dysregulation, understanding the molecular processes linking them has huge implications for disease pathogenesis and therapeutic intervention. In this review, the impacts of metabolic changes on cancer epigenetics are discussed, along with the current knowledge on cancer metabolism and epigenetics.
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Affiliation(s)
- Vishal Chandra
- Cancer Cell and Molecular Biology Branch, Research Institute, National Cancer Center, 323 Ilsan-ro, Ilsandong-gu, Goyang, 410-769, Korea
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Larabi R, Abtouche S, Brahimi M. Theoretical study of methyl group transfer assisted by proton transfer reaction in the N-acylated imidates. J Mol Model 2014; 20:2302. [DOI: 10.1007/s00894-014-2302-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2013] [Accepted: 05/12/2014] [Indexed: 11/28/2022]
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Zhang J, Klinman JP. Enzymatic methyl transfer: role of an active site residue in generating active site compaction that correlates with catalytic efficiency. J Am Chem Soc 2011; 133:17134-7. [PMID: 21958159 DOI: 10.1021/ja207467d] [Citation(s) in RCA: 70] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Human catechol-O-methyltransferase (COMT) catalyzes a methyl transfer from S-adenosylmethionine (AdoMet) to dopamine. Site-specific mutants at three positions (Tyr68, Trp38, and Val108) have been characterized with regard to product distribution, catalytic efficiency, and secondary kinetic isotope effects. The series of mutations at Tyr68 within wild-type protein and the common polymorphic variant (Val108Met) yields a linear correlation between the catalytic efficiency and the size of the secondary kinetic isotope effect. We conclude that active site compaction in COMT is modulated by a proximal side chain residing behind the sulfur-bearing methyl group of AdoMet. These findings are discussed in the context of the active site compression that has been postulated to accompany enzyme-supported hydrogen tunneling.
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Affiliation(s)
- Jianyu Zhang
- Department of Chemistry, University of California, Berkeley, California 94720, USA
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Bender G, Pierce E, Hill JA, Darty JE, Ragsdale SW. Metal centers in the anaerobic microbial metabolism of CO and CO2. Metallomics 2011; 3:797-815. [PMID: 21647480 PMCID: PMC3964926 DOI: 10.1039/c1mt00042j] [Citation(s) in RCA: 55] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
Carbon dioxide and carbon monoxide are important components of the carbon cycle. Major research efforts are underway to develop better technologies to utilize the abundant greenhouse gas, CO(2), for harnessing 'green' energy and producing biofuels. One strategy is to convert CO(2) into CO, which has been valued for many years as a synthetic feedstock for major industrial processes. Living organisms are masters of CO(2) and CO chemistry and, here, we review the elegant ways that metalloenzymes catalyze reactions involving these simple compounds. After describing the chemical and physical properties of CO and CO(2), we shift focus to the enzymes and the metal clusters in their active sites that catalyze transformations of these two molecules. We cover how the metal centers on CO dehydrogenase catalyze the interconversion of CO and CO(2) and how pyruvate oxidoreductase, which contains thiamin pyrophosphate and multiple Fe(4)S(4) clusters, catalyzes the addition and elimination of CO(2) during intermediary metabolism. We also describe how the nickel center at the active site of acetyl-CoA synthase utilizes CO to generate the central metabolite, acetyl-CoA, as part of the Wood-Ljungdahl pathway, and how CO is channelled from the CO dehydrogenase to the acetyl-CoA synthase active site. We cover how the corrinoid iron-sulfur protein interacts with acetyl-CoA synthase. This protein uses vitamin B(12) and a Fe(4)S(4) cluster to catalyze a key methyltransferase reaction involving an organometallic methyl-Co(3+) intermediate. Studies of CO and CO(2) enzymology are of practical significance, and offer fundamental insights into important biochemical reactions involving metallocenters that act as nucleophiles to form organometallic intermediates and catalyze C-C and C-S bond formations.
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Affiliation(s)
- Güneş Bender
- Department of Biological Chemistry, University of Michigan, Ann Arbor, Michigan 48109-0606, USA. Fax: +1 734-763-4581; Tel: +1 734-615-4621
| | - Elizabeth Pierce
- Department of Biological Chemistry, University of Michigan, Ann Arbor, Michigan 48109-0606, USA. Fax: +1 734-763-4581; Tel: +1 734-615-4621
| | - Jeffrey A. Hill
- Department of Biological Chemistry, University of Michigan, Ann Arbor, Michigan 48109-0606, USA. Fax: +1 734-763-4581; Tel: +1 734-615-4621
| | - Joseph E. Darty
- Department of Biological Chemistry, University of Michigan, Ann Arbor, Michigan 48109-0606, USA. Fax: +1 734-763-4581; Tel: +1 734-615-4621
| | - Stephen W. Ragsdale
- Department of Biological Chemistry, University of Michigan, Ann Arbor, Michigan 48109-0606, USA. Fax: +1 734-763-4581; Tel: +1 734-615-4621
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Abstract
Methanogenic archaea of the genus Methanosarcina possess a unique type of metabolism because they use H(2)+CO(2), methylated C(1)-compounds, or acetate as energy and carbon source for growth. The process of methanogenesis is fundamental for the global carbon cycle and represents the terminal step in the anaerobic breakdown of organic matter in freshwater sediments. Moreover, methane is an important greenhouse gas that directly contributes to climate change and global warming. Methanosarcina species convert the aforementioned substrates to CH(4) via the CO(2)-reducing, the methylotrophic, or the aceticlastic pathway. All methanogenic processes finally result in the oxidation of two thiol-containing cofactors (HS-CoM and HS-CoB), leading to the formation of the so-called heterodisulfide (CoM-S-S-CoB) that contains an intermolecular disulfide bridge. This molecule functions as the terminal electron acceptor of a branched respiratory chain. Molecular hydrogen, reduced coenzyme F(420), or reduced ferredoxin are used as electron donors. The key enzymes of the respiratory chain (Ech hydrogenase, F(420)-nonreducing hydrogenase, F(420)H(2) dehydrogenase, and heterodisulfide reductase) couple the redox reactions to proton translocation across the cytoplasmic membrane. The resulting electrochemical proton gradient is the driving force for ATP synthesis. Here, we describe the methods and techniques of how to analyze electron transfer reactions, the process of proton translocation, and the formation of ATP.
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Affiliation(s)
- Cornelia Welte
- Institute of Microbiology and Biotechnology, University of Bonn, Bonn, Germany
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Ragsdale SW, Pierce E. Acetogenesis and the Wood-Ljungdahl pathway of CO(2) fixation. BIOCHIMICA ET BIOPHYSICA ACTA 2008; 1784:1873-98. [PMID: 18801467 PMCID: PMC2646786 DOI: 10.1016/j.bbapap.2008.08.012] [Citation(s) in RCA: 712] [Impact Index Per Article: 44.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/02/2008] [Revised: 08/12/2008] [Accepted: 08/13/2008] [Indexed: 01/04/2023]
Abstract
Conceptually, the simplest way to synthesize an organic molecule is to construct it one carbon at a time. The Wood-Ljungdahl pathway of CO(2) fixation involves this type of stepwise process. The biochemical events that underlie the condensation of two one-carbon units to form the two-carbon compound, acetate, have intrigued chemists, biochemists, and microbiologists for many decades. We begin this review with a description of the biology of acetogenesis. Then, we provide a short history of the important discoveries that have led to the identification of the key components and steps of this usual mechanism of CO and CO(2) fixation. In this historical perspective, we have included reflections that hopefully will sketch the landscape of the controversies, hypotheses, and opinions that led to the key experiments and discoveries. We then describe the properties of the genes and enzymes involved in the pathway and conclude with a section describing some major questions that remain unanswered.
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Affiliation(s)
- Stephen W Ragsdale
- Department of Biological Chemistry, MSRB III, 5301, 1150 W. Medical Center Drive, University of Michigan, Ann Arbor, MI 48109-0606, USA.
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