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Phan HN, Manley OM, Skirboll SS, Cha L, Hilovsky D, Chang WC, Thompson PM, Liu X, Makris TM. Excision of a Protein-Derived Amine for p-Aminobenzoate Assembly by the Self-Sacrificial Heterobimetallic Protein CADD. Biochemistry 2023; 62:3276-3282. [PMID: 37936269 DOI: 10.1021/acs.biochem.3c00406] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2023]
Abstract
Chlamydia protein associating with death domains (CADD), the founding member of a recently discovered class of nonheme dimetal enzymes termed hemeoxygenase-like dimetaloxidases (HDOs), plays an indispensable role in pathogen survival. CADD orchestrates the biosynthesis of p-aminobenzoic acid (pABA) for integration into folate via the self-sacrificial excision of a protein-derived tyrosine (Tyr27) and several additional processing steps, the nature and timing of which have yet to be fully clarified. Nuclear magnetic resonance (NMR) and proteomics approaches reveal the source and probable timing of amine installation by a neighboring lysine (Lys152). Turnover studies using limiting O2 have identified a para-aminobenzaldehyde (pABCHO) metabolic intermediate that is formed on the path to pABA formation. The use of pABCHO and other probe substrates shows that the heterobimetallic Fe/Mn form of the enzyme is capable of oxygen insertion to generate the pABA-carboxylate.
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Affiliation(s)
- Han N Phan
- Department of Molecular and Structural Biochemistry, North Carolina State University, Raleigh, North Carolina 27695, United States
| | - Olivia M Manley
- Department of Molecular and Structural Biochemistry, North Carolina State University, Raleigh, North Carolina 27695, United States
| | - Sydney S Skirboll
- Department of Molecular and Structural Biochemistry, North Carolina State University, Raleigh, North Carolina 27695, United States
| | - Lide Cha
- Department of Chemistry, North Carolina State University, Raleigh, North Carolina 27695, United States
| | - Dalton Hilovsky
- Department of Molecular and Structural Biochemistry, North Carolina State University, Raleigh, North Carolina 27695, United States
| | - Wei-Chen Chang
- Department of Chemistry, North Carolina State University, Raleigh, North Carolina 27695, United States
| | - Peter M Thompson
- Department of Molecular and Structural Biochemistry, North Carolina State University, Raleigh, North Carolina 27695, United States
- The Molecular Education, Technology and Research Innovation Center (METRIC), North Carolina State University, Raleigh, North Carolina 27695, United States
| | - Xiaojing Liu
- Department of Molecular and Structural Biochemistry, North Carolina State University, Raleigh, North Carolina 27695, United States
| | - Thomas M Makris
- Department of Molecular and Structural Biochemistry, North Carolina State University, Raleigh, North Carolina 27695, United States
- Department of Chemistry, North Carolina State University, Raleigh, North Carolina 27695, United States
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Satoh Y, Fukui K, Koma D, Shen N, Lee TS. Engineered Escherichia coli platforms for tyrosine-derivative production from phenylalanine using phenylalanine hydroxylase and tetrahydrobiopterin-regeneration system. BIOTECHNOLOGY FOR BIOFUELS AND BIOPRODUCTS 2023; 16:115. [PMID: 37464414 DOI: 10.1186/s13068-023-02365-5] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/27/2023] [Accepted: 07/02/2023] [Indexed: 07/20/2023]
Abstract
BACKGROUND Aromatic compounds derived from tyrosine are important and diverse chemicals that have industrial and commercial applications. Although these aromatic compounds can be obtained by extraction from natural producers, their growth is slow, and their content is low. To overcome these problems, many of them have been chemically synthesized from petroleum-based feedstocks. However, because of the environmental burden and depleting availability of feedstock, microbial cell factories are attracting much attention as sustainable and environmentally friendly processes. RESULTS To facilitate development of microbial cell factories for producing tyrosine derivatives, we developed simple and convenient tyrosine-producing Escherichia coli platforms with a bacterial phenylalanine hydroxylase, which converted phenylalanine to tyrosine with tetrahydromonapterin as a cofactor, using a synthetic biology approach. By introducing a tetrahydrobiopterin-regeneration system, the tyrosine titer of the plasmid-based engineered strain was 4.63 g/L in a medium supplemented with 5.00 g/L phenylalanine with a test tube. The strains were successfully used to produce industrially attractive compounds, such as tyrosol with a yield of 1.58 g/L by installing a tyrosol-producing module consisting of genes encoding tyrosine decarboxylase and tyramine oxidase on a plasmid. Gene integration into E. coli chromosomes has an advantage over the use of plasmids because it increases genetic stability without antibiotic feeding to the culture media and enables more flexible pathway engineering by accepting more plasmids with artificial pathway genes. Therefore, we constructed a plasmid-free tyrosine-producing platform by integrating five modules, comprising genes encoding the phenylalanine hydroxylase and tetrahydrobiopterin-regeneration system, into the chromosome. The platform strain could produce 1.04 g/L of 3,4-dihydroxyphenylalanine, a drug medicine, by installing a gene encoding tyrosine hydroxylase and the tetrahydrobiopterin-regeneration system on a plasmid. Moreover, by installing the tyrosol-producing module, tyrosol was produced with a yield of 1.28 g/L. CONCLUSIONS We developed novel E. coli platforms for producing tyrosine from phenylalanine at multi-gram-per-liter levels in test-tube cultivation. The platforms allowed development and evaluation of microbial cell factories installing various designed tyrosine-derivative biosynthetic pathways at multi-grams-per-liter levels in test tubes.
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Affiliation(s)
- Yasuharu Satoh
- Faculty of Engineering, Hokkaido University, Sapporo, 060-8628, Japan.
- Graduate School of Chemical Sciences and Engineering, Hokkaido University, Sapporo, 060-8628, Japan.
| | - Keita Fukui
- Research Institute for Bioscience Products & Fine Chemicals, Ajinomoto Co., Inc., Kanagawa, 210-8681, Japan
| | - Daisuke Koma
- Osaka Research Institute of Industrial Science and Technology, Osaka, 536-8553, Japan
| | - Ning Shen
- Graduate School of Chemical Sciences and Engineering, Hokkaido University, Sapporo, 060-8628, Japan
| | - Taek Soon Lee
- Biological Systems and Engineering Division, Lawrence Berkeley National Laboratory, Berkeley, CA, 94720, USA
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Wooldridge R, Stone S, Pedraza A, Ray WK, Helm RF, Allen KD. The Chlamydia trachomatis p-aminobenzoate synthase CADD is a manganese-dependent oxygenase that uses its own amino acid residues as substrates. FEBS Lett 2023; 597:557-572. [PMID: 36647787 DOI: 10.1002/1873-3468.14573] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2022] [Revised: 12/28/2022] [Accepted: 01/02/2023] [Indexed: 01/18/2023]
Abstract
CADD (chlamydia protein associating with death domains) is a p-aminobenzoate (pAB) synthase involved in a noncanonical route for tetrahydrofolate biosynthesis in Chlamydia trachomatis. Although previously implicated to employ a diiron cofactor, here, we show that pAB synthesis by CADD requires manganese and the physiological cofactor is most likely a heterodinuclear Mn/Fe cluster. Isotope-labeling experiments revealed that the two oxygen atoms in the carboxylic acid portion of pAB are derived from molecular oxygen. Further, mass spectrometry-based proteomic analyses of CADD-derived peptides demonstrated a glycine substitution at Tyr27, providing strong evidence that this residue is sacrificed for pAB synthesis. Additionally, Lys152 was deaminated and oxidized to aminoadipic acid, supporting its proposed role as a sacrificial amino group donor.
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Affiliation(s)
| | - Spenser Stone
- Department of Biochemistry, Virginia Tech, Blacksburg, VA, USA
| | - Andrew Pedraza
- Department of Biochemistry, Virginia Tech, Blacksburg, VA, USA
| | - W Keith Ray
- Department of Biochemistry, Virginia Tech, Blacksburg, VA, USA
| | - Richard F Helm
- Department of Biochemistry, Virginia Tech, Blacksburg, VA, USA
| | - Kylie D Allen
- Department of Biochemistry, Virginia Tech, Blacksburg, VA, USA
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Self-sacrificial tyrosine cleavage by an Fe:Mn oxygenase for the biosynthesis of para-aminobenzoate in Chlamydia trachomatis. Proc Natl Acad Sci U S A 2022; 119:e2210908119. [PMID: 36122239 PMCID: PMC9522330 DOI: 10.1073/pnas.2210908119] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Chlamydia protein associating with death domains (CADD) is involved in the biosynthesis of para-aminobenzoate (pABA), an essential component of the folate cofactor that is required for the survival and proliferation of the human pathogen Chlamydia trachomatis. The pathway used by Chlamydiae for pABA synthesis differs from the canonical multi-enzyme pathway used by most bacteria that relies on chorismate as a metabolic precursor. Rather, recent work showed pABA formation by CADD derives from l-tyrosine. As a member of the emerging superfamily of heme oxygenase-like diiron oxidases (HDOs), CADD was proposed to use a diiron cofactor for catalysis. However, we report maximal pABA formation by CADD occurs upon the addition of both iron and manganese, which implicates a heterobimetallic Fe:Mn cluster is the catalytically active form. Isotopic labeling experiments and proteomics studies show that CADD generates pABA from a protein-derived tyrosine (Tyr27), a residue that is ∼14 Å from the dimetal site. We propose that this self-sacrificial reaction occurs through O2 activation by a probable Fe:Mn cluster through a radical relay mechanism that connects to the "substrate" Tyr, followed by amination and direct oxygen insertion. These results provide the molecular basis for pABA formation in C. trachomatis, which will inform the design of novel therapeutics.
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Manley OM, Tang H, Xue S, Guo Y, Chang WC, Makris TM. BesC Initiates C-C Cleavage through a Substrate-Triggered and Reactive Diferric-Peroxo Intermediate. J Am Chem Soc 2021; 143:21416-21424. [PMID: 34898198 PMCID: PMC8876372 DOI: 10.1021/jacs.1c11109] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
BesC catalyzes the iron- and O2-dependent cleavage of 4-chloro-l-lysine to form 4-chloro-l-allylglycine, formaldehyde, and ammonia. This process is a critical step for a biosynthetic pathway that generates a terminal alkyne amino acid which can be leveraged as a useful bio-orthogonal handle for protein labeling. As a member of an emerging family of diiron enzymes that are typified by their heme oxygenase-like fold and a very similar set of coordinating ligands, recently termed HDOs, BesC performs an unusual type of carbon-carbon cleavage reaction that is a significant departure from reactions catalyzed by canonical dinuclear-iron enzymes. Here, we show that BesC activates O2 in a substrate-gated manner to generate a diferric-peroxo intermediate. Examination of the reactivity of the peroxo intermediate with a series of lysine derivatives demonstrates that BesC initiates this unique reaction trajectory via cleavage of the C4-H bond; this process represents the rate-limiting step in a single turnover reaction. The observed reactivity of BesC represents the first example of a dinuclear-iron enzyme that utilizes a diferric-peroxo intermediate to capably cleave a C-H bond as part of its native function, thus circumventing the formation of a high-valent intermediate more commonly associated with substrate monooxygenations.
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Affiliation(s)
- Olivia M. Manley
- Department of Molecular and Structural Biochemistry, North Carolina State University, Raleigh, North Carolina 27695, United States
| | - Haoyu Tang
- Department of Chemistry, North Carolina State University, Raleigh, North Carolina 27695, United States
| | - Shan Xue
- Department of Chemistry, Carnegie Mellon University, Pittsburgh, Pennsylvania 15213, United States
| | - Yisong Guo
- Department of Chemistry, Carnegie Mellon University, Pittsburgh, Pennsylvania 15213, United States
| | - Wei-chen Chang
- Department of Chemistry, North Carolina State University, Raleigh, North Carolina 27695, United States
| | - Thomas M. Makris
- Department of Molecular and Structural Biochemistry, North Carolina State University, Raleigh, North Carolina 27695, United States,Department of Chemistry, North Carolina State University, Raleigh, North Carolina 27695, United States
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An Unusual Route for p-Aminobenzoate Biosynthesis in Chlamydia trachomatis Involves a Probable Self-Sacrificing Diiron Oxygenase. J Bacteriol 2020; 202:JB.00319-20. [PMID: 32967910 DOI: 10.1128/jb.00319-20] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2020] [Accepted: 07/23/2020] [Indexed: 11/20/2022] Open
Abstract
Chlamydia trachomatis lacks the canonical genes required for the biosynthesis of p-aminobenzoate (pABA), a component of essential folate cofactors. Previous studies revealed a single gene from C. trachomatis, the CT610 gene, that rescues Escherichia coli ΔpabA, ΔpabB, and ΔpabC mutants, which are otherwise auxotrophic for pABA. CT610 shares low sequence similarity to nonheme diiron oxygenases, and the previously solved crystal structure revealed a diiron active site. Genetic studies ruled out several potential substrates for CT610-dependent pABA biosynthesis, including chorismate and other shikimate pathway intermediates, leaving the actual precursor(s) unknown. Here, we supplied isotopically labeled potential precursors to E. coli ΔpabA cells expressing CT610 and found that the aromatic portion of tyrosine was highly incorporated into pABA, indicating that tyrosine is a precursor for CT610-dependent pABA biosynthesis. Additionally, in vitro enzymatic experiments revealed that purified CT610 exhibits low pABA synthesis activity under aerobic conditions in the absence of tyrosine or other potential substrates, where only the addition of a reducing agent such as dithiothreitol appears to stimulate pABA production. Furthermore, site-directed mutagenesis studies revealed that two conserved active site tyrosine residues are essential for the pABA synthesis reaction in vitro Thus, the current data are most consistent with CT610 being a unique self-sacrificing enzyme that utilizes its own active site tyrosine residue(s) for pABA biosynthesis in a reaction that requires O2 and a reduced diiron cofactor.IMPORTANCE Chlamydia trachomatis is the most reported sexually transmitted infection in the United States and the leading cause of infectious blindness worldwide. Unlike many other intracellular pathogens that have undergone reductive evolution, C. trachomatis is capable of de novo biosynthesis of the essential cofactor tetrahydrofolate using a noncanonical pathway. Here, we identify the biosynthetic precursor to the p-aminobenzoate (pABA) portion of folate in a process that requires the CT610 enzyme from C. trachomatis We further provide evidence that CT610 is a self-sacrificing or "suicide" enzyme that uses its own amino acid residue(s) as the substrate for pABA synthesis. This work provides the foundation for future investigation of this chlamydial pABA synthase, which could lead to new therapeutic strategies for C. trachomatis infections.
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Saubade F, Hemery YM, Guyot JP, Humblot C. Lactic acid fermentation as a tool for increasing the folate content of foods. Crit Rev Food Sci Nutr 2018; 57:3894-3910. [PMID: 27351520 DOI: 10.1080/10408398.2016.1192986] [Citation(s) in RCA: 60] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
Abstract
Folate is an essential micronutrient involved in numerous vital biological reactions. The dietary consumption of naturally occurring vitamin B9 is often inadequate in many countries, and supplementation or fortification programs (using synthetic folic acid) are implemented to alleviate folate deficiency. Other food-based alternatives are possible, such as the use of lactic acid bacteria (LAB) to synthesize folate during fermentation. Many studies have been conducted on this topic, and promising results were reported for some fermented dairy products. However, in other studies, folate consumption by LAB or rather low folate production were observed, resulting in fermented foods that may not significantly contribute to the recommended B9 intake. In addition, the optimum conditions for folate biosynthesis by LAB are still not clear. The aim of this review was thus to (i) clarify the ability of LAB to produce folate in food products, (ii) check if the production of folate by LAB in various fermented foods is sufficient to meet human vitamin B9 requirements and (iii) suggest ways to optimize folate production by LAB in fermented food products.
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Affiliation(s)
- Fabien Saubade
- a Institute of Research for Development (IRD); UMR 204 Food and Nutrition Research in the Global South (NUTRIPASS) , IRD/University of Montpellier/SupAgro , Montpellier , France
| | - Youna M Hemery
- a Institute of Research for Development (IRD); UMR 204 Food and Nutrition Research in the Global South (NUTRIPASS) , IRD/University of Montpellier/SupAgro , Montpellier , France
| | - Jean-Pierre Guyot
- a Institute of Research for Development (IRD); UMR 204 Food and Nutrition Research in the Global South (NUTRIPASS) , IRD/University of Montpellier/SupAgro , Montpellier , France
| | - Christèle Humblot
- a Institute of Research for Development (IRD); UMR 204 Food and Nutrition Research in the Global South (NUTRIPASS) , IRD/University of Montpellier/SupAgro , Montpellier , France
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8
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Wholly Rickettsia! Reconstructed Metabolic Profile of the Quintessential Bacterial Parasite of Eukaryotic Cells. mBio 2017; 8:mBio.00859-17. [PMID: 28951473 PMCID: PMC5615194 DOI: 10.1128/mbio.00859-17] [Citation(s) in RCA: 85] [Impact Index Per Article: 12.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023] Open
Abstract
Reductive genome evolution has purged many metabolic pathways from obligate intracellular Rickettsia (Alphaproteobacteria; Rickettsiaceae). While some aspects of host-dependent rickettsial metabolism have been characterized, the array of host-acquired metabolites and their cognate transporters remains unknown. This dearth of information has thwarted efforts to obtain an axenic Rickettsia culture, a major impediment to conventional genetic approaches. Using phylogenomics and computational pathway analysis, we reconstructed the Rickettsia metabolic and transport network, identifying 51 host-acquired metabolites (only 21 previously characterized) needed to compensate for degraded biosynthesis pathways. In the absence of glycolysis and the pentose phosphate pathway, cell envelope glycoconjugates are synthesized from three imported host sugars, with a range of additional host-acquired metabolites fueling the tricarboxylic acid cycle. Fatty acid and glycerophospholipid pathways also initiate from host precursors, and import of both isoprenes and terpenoids is required for the synthesis of ubiquinone and the lipid carrier of lipid I and O-antigen. Unlike metabolite-provisioning bacterial symbionts of arthropods, rickettsiae cannot synthesize B vitamins or most other cofactors, accentuating their parasitic nature. Six biosynthesis pathways contain holes (missing enzymes); similar patterns in taxonomically diverse bacteria suggest alternative enzymes that await discovery. A paucity of characterized and predicted transporters emphasizes the knowledge gap concerning how rickettsiae import host metabolites, some of which are large and not known to be transported by bacteria. Collectively, our reconstructed metabolic network offers clues to how rickettsiae hijack host metabolic pathways. This blueprint for growth determinants is an important step toward the design of axenic media to rescue rickettsiae from the eukaryotic cell. A hallmark of obligate intracellular bacteria is the tradeoff of metabolic genes for the ability to acquire host metabolites. For species of Rickettsia, arthropod-borne parasites with the potential to cause serious human disease, the range of pilfered host metabolites is unknown. This information is critical for dissociating rickettsiae from eukaryotic cells to facilitate rickettsial genetic manipulation. In this study, we reconstructed the Rickettsia metabolic network and identified 51 host metabolites required to compensate patchwork Rickettsia biosynthesis pathways. Remarkably, some metabolites are not known to be transported by any bacteria, and overall, few cognate transporters were identified. Several pathways contain missing enzymes, yet similar pathways in unrelated bacteria indicate convergence and possible novel enzymes awaiting characterization. Our work illuminates the parasitic nature by which rickettsiae hijack host metabolism to counterbalance numerous disintegrated biosynthesis pathways that have arisen through evolution within the eukaryotic cell. This metabolic blueprint reveals what a Rickettsia axenic medium might entail.
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Underlying mechanisms for syntrophic metabolism of essential enzyme cofactors in microbial communities. ISME JOURNAL 2017; 11:1434-1446. [PMID: 28186498 DOI: 10.1038/ismej.2017.2] [Citation(s) in RCA: 64] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/31/2016] [Revised: 11/11/2016] [Accepted: 12/19/2016] [Indexed: 12/31/2022]
Abstract
Many microorganisms are unable to synthesize essential B vitamin-related enzyme cofactors de novo. The underlying mechanisms by which such microbes survive in multi-species communities are largely unknown. We previously reported the near-complete genome sequence of two ~18-member unicyanobacterial microbial consortia that maintain stable membership on defined medium lacking vitamins. Here we have used genome analysis and growth studies on isolates derived from the consortia to reconstruct pathways for biogenesis of eight essential cofactors and predict cofactor usage and precursor exchange in these communities. Our analyses revealed that all but the two Halomonas and cyanobacterial community members were auxotrophic for at least one cofactor. We also observed a mosaic distribution of salvage routes for a variety of cofactor precursors, including those produced by photolysis. Potentially bidirectional transporters were observed to be preferentially in prototrophs, suggesting a mechanism for controlled precursor release. Furthermore, we found that Halomonas sp. do not require cobalamin nor control its synthesis, supporting the hypothesis that they overproduce and export vitamins. Collectively, these observations suggest that the consortia rely on syntrophic metabolism of cofactors as a survival strategy for optimization of metabolic exchange within a shared pool of micronutrients.
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Adams NE, Thiaville JJ, Proestos J, Juárez-Vázquez AL, McCoy AJ, Barona-Gómez F, Iwata-Reuyl D, de Crécy-Lagard V, Maurelli AT. Promiscuous and adaptable enzymes fill "holes" in the tetrahydrofolate pathway in Chlamydia species. mBio 2014; 5:e01378-14. [PMID: 25006229 PMCID: PMC4161248 DOI: 10.1128/mbio.01378-14] [Citation(s) in RCA: 40] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2014] [Accepted: 06/03/2014] [Indexed: 11/20/2022] Open
Abstract
Folates are tripartite molecules comprising pterin, para-aminobenzoate (PABA), and glutamate moieties, which are essential cofactors involved in DNA and amino acid synthesis. The obligately intracellular Chlamydia species have lost several biosynthetic pathways for essential nutrients which they can obtain from their host but have retained the capacity to synthesize folate. In most bacteria, synthesis of the pterin moiety of folate requires the FolEQBK enzymes, while synthesis of the PABA moiety is carried out by the PabABC enzymes. Bioinformatic analyses reveal that while members of Chlamydia are missing the genes for FolE (GTP cyclohydrolase) and FolQ, which catalyze the initial steps in de novo synthesis of the pterin moiety, they have genes for the rest of the pterin pathway. We screened a chlamydial genomic library in deletion mutants of Escherichia coli to identify the "missing genes" and identified a novel enzyme, TrpFCtL2, which has broad substrate specificity. TrpFCtL2, in combination with GTP cyclohydrolase II (RibA), the first enzyme of riboflavin synthesis, provides a bypass of the first two canonical steps in folate synthesis catalyzed by FolE and FolQ. Notably, TrpFCtL2 retains the phosphoribosyl anthranilate isomerase activity of the original annotation. Additionally, we independently confirmed the recent discovery of a novel enzyme, CT610, which uses an unknown precursor to synthesize PABA and complements E. coli mutants with deletions of pabA, pabB, or pabC. Thus, Chlamydia species have evolved a variant folate synthesis pathway that employs a patchwork of promiscuous and adaptable enzymes recruited from other biosynthetic pathways. Importance: Collectively, the involvement of TrpFCtL2 and CT610 in the tetrahydrofolate pathway completes our understanding of folate biosynthesis in Chlamydia. Moreover, the novel roles for TrpFCtL2 and CT610 in the tetrahydrofolate pathway are sophisticated examples of how enzyme evolution plays a vital role in the adaptation of obligately intracellular organisms to host-specific niches. Enzymes like TrpFCtL2 which possess an enzyme fold common to many other enzymes are highly versatile and possess the capacity to evolve to catalyze related reactions in two different metabolic pathways. The continued identification of unique enzymes such as these in bacterial pathogens is important for development of antimicrobial compounds, as drugs that inhibit such enzymes would likely not have any targets in the host or the host's normal microbial flora.
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Affiliation(s)
- Nancy E Adams
- Department of Microbiology and Immunology, F. Edward Hébert School of Medicine, Uniformed Services University, Bethesda, Maryland, USA
| | - Jennifer J Thiaville
- Department of Microbiology and Cell Science, University of Florida, Gainesville, Florida, USA
| | - James Proestos
- Department of Chemistry, Portland State University, Portland, Oregon, USA
| | - Ana L Juárez-Vázquez
- Evolution of Metabolic Diversity Laboratory, Laboratorio Nacional de Genómica para la Biodiversidad (Langebio), Cinvestav-IPN, Irapuato, Mexico
| | - Andrea J McCoy
- Department of Microbiology and Immunology, F. Edward Hébert School of Medicine, Uniformed Services University, Bethesda, Maryland, USA
| | - Francisco Barona-Gómez
- Evolution of Metabolic Diversity Laboratory, Laboratorio Nacional de Genómica para la Biodiversidad (Langebio), Cinvestav-IPN, Irapuato, Mexico
| | - Dirk Iwata-Reuyl
- Department of Chemistry, Portland State University, Portland, Oregon, USA
| | - Valérie de Crécy-Lagard
- Department of Microbiology and Cell Science, University of Florida, Gainesville, Florida, USA
| | - Anthony T Maurelli
- Department of Microbiology and Immunology, F. Edward Hébert School of Medicine, Uniformed Services University, Bethesda, Maryland, USA
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de Crécy-Lagard V. Variations in metabolic pathways create challenges for automated metabolic reconstructions: Examples from the tetrahydrofolate synthesis pathway. Comput Struct Biotechnol J 2014; 10:41-50. [PMID: 25210598 PMCID: PMC4151868 DOI: 10.1016/j.csbj.2014.05.008] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022] Open
Abstract
The availability of thousands of sequenced genomes has revealed the diversity of biochemical solutions to similar chemical problems. Even for molecules at the heart of metabolism, such as cofactors, the pathway enzymes first discovered in model organisms like Escherichia coli or Saccharomyces cerevisiae are often not universally conserved. Tetrahydrofolate (THF) (or its close relative tetrahydromethanopterin) is a universal and essential C1-carrier that most microbes and plants synthesize de novo. The THF biosynthesis pathway and enzymes are, however, not universal and alternate solutions are found for most steps, making this pathway a challenge to annotate automatically in many genomes. Comparing THF pathway reconstructions and functional annotations of a chosen set of folate synthesis genes in specific prokaryotes revealed the strengths and weaknesses of different microbial annotation platforms. This analysis revealed that most current platforms fail in metabolic reconstruction of variant pathways. However, all the pieces are in place to quickly correct these deficiencies if the different databases were built on each other's strengths.
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Affiliation(s)
- Valérie de Crécy-Lagard
- Department of Microbiology and Cell Science and Genetics Institute, University of Florida, Gainesville, FL, United States
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