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Wienhausen G, Moraru C, Bruns S, Tran DQ, Sultana S, Wilkes H, Dlugosch L, Azam F, Simon M. Ligand cross-feeding resolves bacterial vitamin B 12 auxotrophies. Nature 2024; 629:886-892. [PMID: 38720071 DOI: 10.1038/s41586-024-07396-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2021] [Accepted: 04/08/2024] [Indexed: 05/24/2024]
Abstract
Cobalamin (vitamin B12, herein referred to as B12) is an essential cofactor for most marine prokaryotes and eukaryotes1,2. Synthesized by a limited number of prokaryotes, its scarcity affects microbial interactions and community dynamics2-4. Here we show that two bacterial B12 auxotrophs can salvage different B12 building blocks and cooperate to synthesize B12. A Colwellia sp. synthesizes and releases the activated lower ligand α-ribazole, which is used by another B12 auxotroph, a Roseovarius sp., to produce the corrin ring and synthesize B12. Release of B12 by Roseovarius sp. happens only in co-culture with Colwellia sp. and only coincidently with the induction of a prophage encoded in Roseovarius sp. Subsequent growth of Colwellia sp. in these conditions may be due to the provision of B12 by lysed cells of Roseovarius sp. Further evidence is required to support a causative role for prophage induction in the release of B12. These complex microbial interactions of ligand cross-feeding and joint B12 biosynthesis seem to be widespread in marine pelagic ecosystems. In the western and northern tropical Atlantic Ocean, bacteria predicted to be capable of salvaging cobinamide and synthesizing only the activated lower ligand outnumber B12 producers. These findings add new players to our understanding of B12 supply to auxotrophic microorganisms in the ocean and possibly in other ecosystems.
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Affiliation(s)
- Gerrit Wienhausen
- Institute for Chemistry and Biology of the Marine Environment (ICBM), School of Mathematics and Science, Carl von Ossietzky Universität Oldenburg, Oldenburg, Germany.
- Scripps Institution of Oceanography, Marine Biology Research Division, University of California San Diego, La Jolla, CA, USA.
| | - Cristina Moraru
- Institute for Chemistry and Biology of the Marine Environment (ICBM), School of Mathematics and Science, Carl von Ossietzky Universität Oldenburg, Oldenburg, Germany
- Environmental Metagenomics, Research Center One Health Ruhr of the University Alliance Ruhr, Faculty of Chemistry, University of Duisburg-Essen, Essen, Germany
| | - Stefan Bruns
- Institute for Chemistry and Biology of the Marine Environment (ICBM), School of Mathematics and Science, Carl von Ossietzky Universität Oldenburg, Oldenburg, Germany
| | - Den Quoc Tran
- Institute for Chemistry and Biology of the Marine Environment (ICBM), School of Mathematics and Science, Carl von Ossietzky Universität Oldenburg, Oldenburg, Germany
| | - Sabiha Sultana
- Institute for Chemistry and Biology of the Marine Environment (ICBM), School of Mathematics and Science, Carl von Ossietzky Universität Oldenburg, Oldenburg, Germany
| | - Heinz Wilkes
- Institute for Chemistry and Biology of the Marine Environment (ICBM), School of Mathematics and Science, Carl von Ossietzky Universität Oldenburg, Oldenburg, Germany
| | - Leon Dlugosch
- Institute for Chemistry and Biology of the Marine Environment (ICBM), School of Mathematics and Science, Carl von Ossietzky Universität Oldenburg, Oldenburg, Germany
| | - Farooq Azam
- Scripps Institution of Oceanography, Marine Biology Research Division, University of California San Diego, La Jolla, CA, USA
| | - Meinhard Simon
- Institute for Chemistry and Biology of the Marine Environment (ICBM), School of Mathematics and Science, Carl von Ossietzky Universität Oldenburg, Oldenburg, Germany.
- Helmholtz Institute for Functional Marine Biodiversity at the University of Oldenburg (HIFMB), Oldenburg, Germany.
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2
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Mathur Y, Hazra AB. Methylations in vitamin B 12 biosynthesis and catalysis. Curr Opin Struct Biol 2022; 77:102490. [PMID: 36371846 DOI: 10.1016/j.sbi.2022.102490] [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: 05/10/2022] [Revised: 09/30/2022] [Accepted: 10/04/2022] [Indexed: 11/12/2022]
Abstract
Vitamin B12 is an essential biomolecule that assists in the catalysis of methyl transfer and radical-based reactions in cellular metabolism. The structure of B12 is characterized by a tetrapyrrolic corrin ring with a central cobalt ion coordinated with an upper ligand, and a lower ligand anchored via a nucleotide loop. Multiple methyl groups decorate B12, and their presence (or absence) have structural and functional consequences. In this minireview, we focus on the methyl groups that distinguish vitamin B12 from other tetrapyrrolic biomolecules and from its own naturally occurring analogues called cobamides. We draw information from recent advances in the field to understand the origins of these methyl groups and the enzymes that incorporate them, and discuss their biological significance.
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Affiliation(s)
- Yamini Mathur
- Department of Biology, Indian Institute of Science Education and Research, Pune, India. https://twitter.com/yaminipmathur
| | - Amrita B Hazra
- Department of Biology, Indian Institute of Science Education and Research, Pune, India; Department of Chemistry, Indian Institute of Science Education and Research, Pune, India.
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3
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Abstract
The skin microbiome is a key player in human health, with diverse functions ranging from defense against pathogens to education of the immune system. While recent studies have begun to shed light on the valuable role that skin microorganisms have in maintaining the skin barrier, a detailed understanding of the complex interactions that shape healthy skin microbial communities is limited. Cobamides, the vitamin B12 class of cofactor, are essential for organisms across the tree of life. Because this vitamin is only produced by a limited fraction of prokaryotes, cobamide sharing is predicted to mediate community dynamics within microbial communities. Here, we provide the first large-scale metagenomic assessment of cobamide biosynthesis and utilization in the skin microbiome. We show that while numerous and diverse taxa across the major bacterial phyla on the skin encode cobamide-dependent enzymes, relatively few species encode de novo cobamide biosynthesis. We show that cobamide producers and users are integrated into the network structure of microbial communities across the different microenvironments of the skin and that changes in microbiome community structure and diversity are associated with the abundance of cobamide producers in the Corynebacterium genus, for both healthy and diseased skin states. Finally, we find that de novo cobamide biosynthesis is enriched only in Corynebacterium species associated with hosts, including those prevalent on human skin. We confirm that the cofactor is produced in excess through quantification of cobamide production by human skin-associated species isolated in the laboratory. Taken together, our results reveal the potential for cobamide sharing within skin microbial communities, which we hypothesize mediates microbiome community dynamics and host interactions. IMPORTANCE The skin microbiome is essential for maintaining skin health and function. However, the microbial interactions that dictate microbiome structure, stability, and function are not well understood. Here, we investigate the biosynthesis and use of cobamides, a cofactor needed by many organisms but only produced by select prokaryotes, within the human skin microbiome. We found that while a large proportion of skin taxa encode cobamide-dependent enzymes, only a select few encode de novo cobamide biosynthesis. Further, the abundance of cobamide-producing Corynebacterium species is associated with skin microbiome diversity and structure, and within this genus, de novo biosynthesis is enriched in host-associated species compared to environment-associated species. These findings identify cobamides as a potential mediator of skin microbiome dynamics and skin health.
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Cobalamin Riboswitches Are Broadly Sensitive to Corrinoid Cofactors to Enable an Efficient Gene Regulatory Strategy. mBio 2022; 13:e0112122. [PMID: 35993747 PMCID: PMC9600662 DOI: 10.1128/mbio.01121-22] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023] Open
Abstract
In bacteria, many essential metabolic processes are controlled by riboswitches, gene regulatory RNAs that directly bind and detect metabolites. Highly specific effector binding enables riboswitches to respond to a single biologically relevant metabolite. Cobalamin riboswitches are a potential exception because over a dozen chemically similar but functionally distinct cobalamin variants (corrinoid cofactors) exist in nature. Here, we measured cobalamin riboswitch activity in vivo using a Bacillus subtilis fluorescent reporter system and found, among 38 tested riboswitches, a subset responded to corrinoids promiscuously, while others were semiselective. Analyses of chimeric riboswitches and structural models indicate, unlike other riboswitch classes, cobalamin riboswitches indirectly differentiate among corrinoids by sensing differences in their structural conformation. This regulatory strategy aligns riboswitch-corrinoid specificity with cellular corrinoid requirements in a B. subtilis model. Thus, bacteria can employ broadly sensitive riboswitches to cope with the chemical diversity of essential metabolites. IMPORTANCE Some bacterial mRNAs contain a region called a riboswitch which controls gene expression by binding to a metabolite in the cell. Typically, riboswitches sense and respond to a limited range of cellular metabolites, often just one type. In this work, we found the cobalamin (vitamin B12) riboswitch class is an exception, capable of sensing and responding to multiple variants of B12-collectively called corrinoids. We found cobalamin riboswitches vary in corrinoid specificity with some riboswitches responding to each of the corrinoids we tested, while others responding only to a subset of corrinoids. Our results suggest the latter class of riboswitches sense intrinsic conformational differences among corrinoids in order to support the corrinoid-specific needs of the cell. These findings provide insight into how bacteria sense and respond to an exceptionally diverse, often essential set of enzyme cofactors.
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5
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Abstract
All organisms rely on complex metabolites such as amino acids, nucleotides, and cofactors for essential metabolic processes. Some microbes synthesize these fundamental ingredients of life de novo, while others rely on uptake to fulfill their metabolic needs. Although certain metabolic processes are inherently "leaky," the mechanisms enabling stable metabolite provisioning among microbes in the absence of a host remain largely unclear. In particular, how can metabolite provisioning among free-living bacteria be maintained under the evolutionary pressure to economize resources? Salvaging, the process of "recycling and reusing," can be a metabolically efficient route to obtain access to required resources. Here, we show experimentally how precursor salvaging in engineered Escherichia coli populations can lead to stable, long-term metabolite provisioning. We find that salvaged cobamides (vitamin B12 and related enzyme cofactors) are readily made available to nonproducing population members, yet salvagers are strongly protected from overexploitation. We also describe a previously unnoted benefit of precursor salvaging, namely, the removal of the nonfunctional, proliferation-inhibiting precursor. As long as compatible precursors are present, any microbe possessing the terminal steps of a biosynthetic process can, in principle, forgo de novo biosynthesis in favor of salvaging. Consequently, precursor salvaging likely represents a potent, yet overlooked, alternative to de novo biosynthesis for the acquisition and provisioning of metabolites in free-living bacterial populations. IMPORTANCE Recycling gives new life to old things. Bacteria have the ability to recycle and reuse complex molecules they encounter in their environment to fulfill their basic metabolic needs in a resource-efficient way. By studying the salvaging (recycling and reusing) of vitamin B12 precursors, we found that metabolite salvaging can benefit others and provide stability to a bacterial community at the same time. Salvagers of vitamin B12 precursors freely share the result of their labor yet cannot be outcompeted by freeloaders, likely because salvagers retain preferential access to the salvaging products. Thus, salvaging may represent an effective, yet overlooked, mechanism of acquiring and provisioning nutrients in microbial populations.
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Mathur Y, Vartak AR, Hazra AB. Guardian of cobamide diversity: Probing the role of CobT in lower ligand activation in the biosynthesis of vitamin B 12 and other cobamide cofactors. Methods Enzymol 2022; 668:25-59. [PMID: 35589196 DOI: 10.1016/bs.mie.2022.01.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
Enzymes catalyze a wide variety of reactions with exquisite precision under crowded conditions within cellular environments. When encountered with a choice of small molecules in their vicinity, even though most enzymes continue to be specific about the substrate they pick, some others are able to accept a range of substrates and subsequently produce a variety of products. The biosynthesis of Vitamin B12, an essential nutrient required by humans involves a multi-substrate α-phosphoribosyltransferase enzyme CobT that activates the lower ligand of B12. Vitamin B12 is a member of the cobamide family of cofactors which share a common tetrapyrrolic corrin scaffold with a centrally coordinated cobalt ion, and an upper and a lower ligand. The structural difference between B12 and other cobamides mainly arises from variations in the lower ligand, which is attached to the activated corrin ring by CobT and other downstream enzymes. In this chapter, we describe the steps involved in identifying and reconstituting the activity of new CobT homologs by deriving lessons from those previously characterized. We then highlight biochemical techniques to study the unique properties of these homologs. Finally, we describe a pairwise substrate competition assay to rank CobT substrate preference, a general method that can be applied for the study of other multi-substrate enzymes. Overall, the analysis with CobT provides insights into the range of cobamides that can be synthesized by an organism or a community, complementing efforts to predict cobamide diversity from complex metagenomic data.
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Affiliation(s)
- Yamini Mathur
- Department of Biology, Indian Institute of Science Education and Research Pune, Pune, India
| | - Aniket R Vartak
- Department of Biology, Indian Institute of Science Education and Research Pune, Pune, India
| | - Amrita B Hazra
- Department of Biology, Indian Institute of Science Education and Research Pune, Pune, India; Department of Chemistry, Indian Institute of Science Education and Research Pune, Pune, India.
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7
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Ma AT, Kantner DS, Beld J. Cobamide remodeling. VITAMINS AND HORMONES 2022; 119:43-63. [PMID: 35337629 DOI: 10.1016/bs.vh.2022.01.004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
Cobamides are a family of structurally-diverse cofactors which includes vitamin B12 and over a dozen natural analogs. Within the nucleotide loop structure, cobamide analogs have variable lower ligands that fall into three categories: benzimidazoles, purines, and phenols. The range of cobamide analogs that can be utilized by an organism is dependent on the specificity of its cobamide-dependent enzymes, and most bacteria are able to utilize multiple analogs but not all. Some bacteria have pathways for cobamide remodeling, a process in which imported cobamides are converted into compatible analogs. Here we discuss cobamide analog diversity and three pathways for cobamide remodeling, mediated by amidohydrolase CbiZ, phosphodiesterase CbiR, and some homologs of cobamide synthase CobS. Remodeling proteins exhibit varying degrees of specificity for cobamide substrates, reflecting different strategies to ensure that imported cobamides can be utilized.
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Affiliation(s)
- Amy T Ma
- Department of Microbiology and Immunology, Center for Advanced Microbial Processing, Institute for Molecular Medicine and Infectious Disease, Drexel University College of Medicine, Philadelphia, PA, United States.
| | - Daniel S Kantner
- Department of Microbiology and Immunology, Center for Advanced Microbial Processing, Institute for Molecular Medicine and Infectious Disease, Drexel University College of Medicine, Philadelphia, PA, United States
| | - Joris Beld
- Department of Microbiology and Immunology, Center for Advanced Microbial Processing, Institute for Molecular Medicine and Infectious Disease, Drexel University College of Medicine, Philadelphia, PA, United States
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8
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Direct Cobamide Remodeling via Additional Function of Cobamide Biosynthesis Protein CobS from Vibrio cholerae. J Bacteriol 2021; 203:e0017221. [PMID: 34031037 DOI: 10.1128/jb.00172-21] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
Vitamin B12 belongs to a family of structurally diverse cofactors with over a dozen natural analogs, collectively referred to as cobamides. Most bacteria encode cobamide-dependent enzymes, many of which can only utilize a subset of cobamide analogs. Some bacteria employ a mechanism called cobamide remodeling, a process in which cobamides are converted into other analogs to ensure that compatible cobamides are available in the cell. Here, we characterize an additional pathway for cobamide remodeling that is distinct from the previously characterized ones. Cobamide synthase (CobS) is an enzyme required for cobamide biosynthesis that attaches the lower ligand moiety in which the base varies between analogs. In a heterologous model system, we previously showed that Vibrio cholerae CobS (VcCobS) unexpectedly conferred remodeling activity in addition to performing the known cobamide biosynthesis reaction. Here, we show that additional Vibrio species perform the same remodeling reaction, and we further characterize VcCobS-mediated remodeling using bacterial genetics and in vitro assays. We demonstrate that VcCobS acts upon the cobamide pseudocobalamin directly to remodel it, a mechanism which differs from the known remodeling pathways in which cobamides are first cleaved into biosynthetic intermediates. This suggests that some CobS homologs have the additional function of cobamide remodeling, and we propose the term "direct remodeling" for this process. This characterization of yet another pathway for remodeling suggests that cobamide profiles are highly dynamic in polymicrobial environments, with remodeling pathways conferring a competitive advantage. IMPORTANCE Cobamides are widespread cofactors that mediate metabolic interactions in complex microbial communities. Few studies directly examine cobamide profiles, but several have shown that mammalian gastrointestinal tracts are rich in cobamide analogs. Studies of intestinal bacteria, including beneficial commensals and pathogens, show variation in the ability to produce and utilize different cobamides. Some bacteria can convert imported cobamides into compatible analogs in a process called remodeling. Recent discoveries of additional cobamide remodeling pathways, including this work, suggest that remodeling is an important factor in cobamide dynamics. Characterization of such pathways is critical in understanding cobamide flux and nutrient cross-feeding in polymicrobial communities, and it facilitates the establishment of microbiome manipulation strategies via modulation of cobamide profiles.
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9
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Law KP, He W, Tao J, Zhang C. Characterization of the Exometabolome of Nitrosopumilus maritimus SCM1 by Liquid Chromatography-Ion Mobility Mass Spectrometry. Front Microbiol 2021; 12:658781. [PMID: 34276593 PMCID: PMC8281238 DOI: 10.3389/fmicb.2021.658781] [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: 01/26/2021] [Accepted: 05/04/2021] [Indexed: 11/13/2022] Open
Abstract
Marine Thaumarchaeota (formerly known as the marine group I archaea) have received much research interest in recent years since these chemolithoautotrophic organisms are abundant in the subsurface ocean and oxidize ammonium to nitrite, which makes them a major contributor to the marine carbon and nitrogen cycles. However, few studies have investigated the chemical composition of their exometabolome and their contributions to the pool of dissolved organic matter (DOM) in seawater. This study exploits the recent advances in ion mobility mass spectrometry (IM-MS) and integrates this instrumental capability with bioinformatics to reassess the exometabolome of a model ammonia-oxidizing archaeon, Nitrosopumilus maritimus strain SCM1. Our method has several advantages over the conventional approach using an Orbitrap or ion cyclotron resonance mass analyzer and allows assignments or annotations of spectral features to known metabolites confidently and indiscriminately, as well as distinction of biological molecules from background organics. Consistent with the results of a previous report, the SPE-extracted exometabolome of N. maritimus is dominated by biologically active nitrogen-containing metabolites, in addition to peptides secreted extracellularly. Cobalamin and associated intermediates, including α-ribazole and α-ribazole 5′-phosphate, are major components of the SPE-extracted exometabolome of N. maritimus. This supports the proposition that Thaumarchaeota have the capacity of de novo biosynthesizing cobalamin. Other biologically significant metabolites, such as agmatidine and medicagenate, predicted by genome screening are also detected, which indicates that Thaumarchaeota have remarkable metabolic potentials, underlining their importance in driving elemental cycles critical to biological processes in the ocean.
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Affiliation(s)
- Kai P Law
- SUSTech Academy for Advanced Interdisciplinary Studies, Southern University of Science and Technology, Shenzhen, China.,Shenzhen Key Laboratory of Marine Geo-Omics Research, Southern University of Science and Technology, Shenzhen, China.,Department of Ocean Science and Engineering, Southern University of Science and Technology, Shenzhen, China
| | - Wei He
- Shenzhen Key Laboratory of Marine Geo-Omics Research, Southern University of Science and Technology, Shenzhen, China.,Department of Ocean Science and Engineering, Southern University of Science and Technology, Shenzhen, China
| | - Jianchang Tao
- Shenzhen Key Laboratory of Marine Geo-Omics Research, Southern University of Science and Technology, Shenzhen, China.,Department of Ocean Science and Engineering, Southern University of Science and Technology, Shenzhen, China
| | - Chuanlun Zhang
- Shenzhen Key Laboratory of Marine Geo-Omics Research, Southern University of Science and Technology, Shenzhen, China.,Department of Ocean Science and Engineering, Southern University of Science and Technology, Shenzhen, China.,Southern Marine Science and Engineering Guangdong Laboratory (Guangzhou), Guangzhou, China.,Shanghai Sheshan National Geophysical Observatory, Shanghai, China
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10
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Mattes TA, Malalasekara L, Escalante-Semerena JC. Functional Studies of α-Riboside Activation by the α-Ribazole Kinase (CblS) from Geobacillus kaustophilus. Biochemistry 2021; 60:2011-2021. [PMID: 34105957 DOI: 10.1021/acs.biochem.1c00119] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
We report the initial characterization of the α-ribazole (α-R) kinase enzyme of Geobacillus kaustophilus (GkCblS), which converts α-R to α-R-phosphate (α-RP) during the synthesis of cobamides. We implemented a continuous spectrophotometric assay to obtain kinetic parameters for several potential substrates and to study the specificity of the enzyme for α-N-linked ribosides. The apparent Km values for α-R and ATP were 358 and 297 μM, respectively. We also report methods for synthesizing and quantifying non-commercially available α-ribosides and β-ribazole (β-R). Purified GkCblS activated α-R and other α-ribosides, including α-adenosine (α-Ado). GkCblS did not phosphorylate β-N-linked glycosides like β-adenosine or β-R. Expression of G. kaustophilus cblS+ in a Salmonella enterica subsp. enterica sv Typhimurium LT2 (S. enterica) strain lacking the nicotinate mononucleotide:5,6-dimethylbenzimidazole phosphoribosyl transferase (CobT) enzyme resulted in the activation of various benzimidazole α-ribosides, and the synthesis of benzimidazolyl cobamides to levels that supported robust growth. Notably, α-Ado did not support growth under similar conditions, in spite of the fact that GkCblS phosphorylated α-Ado in vitro. When α-Ado was provided at a very high concentration, growth was observed. This result suggested that in S. enterica α-Ado transport may be inefficient. We conclude that GkCblS has specificity for α-N-glycosidic bonds, but not for the base in α-ribosides.
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Affiliation(s)
- Theodoric A Mattes
- Department of Microbiology, University of Georgia, Athens, Georgia 30602, United States
| | - Lahiru Malalasekara
- Department of Microbiology, University of Georgia, Athens, Georgia 30602, United States
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11
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Mathur Y, Sreyas S, Datar PM, Sathian MB, Hazra AB. CobT and BzaC catalyze the regiospecific activation and methylation of the 5-hydroxybenzimidazole lower ligand in anaerobic cobamide biosynthesis. J Biol Chem 2020; 295:10522-10534. [PMID: 32503839 PMCID: PMC7397103 DOI: 10.1074/jbc.ra120.014197] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2020] [Revised: 06/01/2020] [Indexed: 11/06/2022] Open
Abstract
Vitamin B12 and other cobamides are essential cofactors required by many organisms and are synthesized by a subset of prokaryotes via distinct aerobic and anaerobic routes. The anaerobic biosynthesis of 5,6-dimethylbenzimidazole (DMB), the lower ligand of vitamin B12, involves five reactions catalyzed by the bza operon gene products, namely the hydroxybenzimidazole synthase BzaAB/BzaF, phosphoribosyltransferase CobT, and three methyltransferases, BzaC, BzaD, and BzaE, that conduct three distinct methylation steps. Of these, the methyltransferases that contribute to benzimidazole lower ligand diversity in cobamides remain to be characterized, and the precise role of the bza operon protein CobT is unclear. In this study, we used the bza operon from the anaerobic bacterium Moorella thermoacetica (comprising bzaA-bzaB-cobT-bzaC) to examine the role of CobT and investigate the activity of the first methyltransferase, BzaC. We studied the phosphoribosylation catalyzed by MtCobT and found that it regiospecifically activates 5-hydroxybenzimidazole (5-OHBza) to form the 5-OHBza-ribotide (5-OHBza-RP) isomer as the sole product. Next, we characterized the domains of MtBzaC and reconstituted its methyltransferase activity with the predicted substrate 5-OHBza and with two alternative substrates, the MtCobT product 5-OHBza-RP and its riboside derivative 5-OHBza-R. Unexpectedly, we found that 5-OHBza-R is the most favored MtBzaC substrate. Our results collectively explain the long-standing observation that the attachment of the lower ligand in anaerobic cobamide biosynthesis is regiospecific. In conclusion, we validate MtBzaC as a SAM:hydroxybenzimidazole-riboside methyltransferase (HBIR-OMT). Finally, we propose a new pathway for the synthesis and activation of the benzimidazolyl lower ligand in anaerobic cobamide biosynthesis.
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Affiliation(s)
- Yamini Mathur
- Department of Biology, Indian Institute of Science Education and Research, Pune, India
| | - Sheryl Sreyas
- Department of Chemistry, Indian Institute of Science Education and Research, Pune, India
| | - Prathamesh M Datar
- Department of Chemistry, Indian Institute of Science Education and Research, Pune, India
| | - Manjima B Sathian
- Department of Chemistry, Indian Institute of Science Education and Research, Pune, India
| | - Amrita B Hazra
- Department of Biology, Indian Institute of Science Education and Research, Pune, India
- Department of Chemistry, Indian Institute of Science Education and Research, Pune, India
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12
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Sokolovskaya OM, Shelton AN, Taga ME. Sharing vitamins: Cobamides unveil microbial interactions. Science 2020; 369:369/6499/eaba0165. [PMID: 32631870 DOI: 10.1126/science.aba0165] [Citation(s) in RCA: 88] [Impact Index Per Article: 22.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Microbial communities are essential to fundamental processes on Earth. Underlying the compositions and functions of these communities are nutritional interdependencies among individual species. One class of nutrients, cobamides (the family of enzyme cofactors that includes vitamin B12), is widely used for a variety of microbial metabolic functions, but these structurally diverse cofactors are synthesized by only a subset of bacteria and archaea. Advances at different scales of study-from individual isolates, to synthetic consortia, to complex communities-have led to an improved understanding of cobamide sharing. Here, we discuss how cobamides affect microbes at each of these three scales and how integrating different approaches leads to a more complete understanding of microbial interactions.
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Affiliation(s)
- Olga M Sokolovskaya
- Department of Plant & Microbial Biology, University of California, Berkeley, Berkeley, CA, USA
| | - Amanda N Shelton
- Department of Plant & Microbial Biology, University of California, Berkeley, Berkeley, CA, USA
| | - Michiko E Taga
- Department of Plant & Microbial Biology, University of California, Berkeley, Berkeley, CA, USA.
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13
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Perruchon C, Vasileiadis S, Papadopoulou ES, Karpouzas DG. Genome-Based Metabolic Reconstruction Unravels the Key Role of B12 in Methionine Auxotrophy of an Ortho-Phenylphenol-Degrading Sphingomonas haloaromaticamans. Front Microbiol 2020; 10:3009. [PMID: 31998277 PMCID: PMC6970198 DOI: 10.3389/fmicb.2019.03009] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2019] [Accepted: 12/16/2019] [Indexed: 12/30/2022] Open
Abstract
Auxotrophy to amino acids and vitamins is a common feature in the bacterial world shaping microbial communities through cross-feeding relations. The amino acid auxotrophy of pollutant-degrading bacteria could hamper their bioremediation potential, however, the underlying mechanisms of auxotrophy remain unexplored. We employed genome sequence-based metabolic reconstruction to identify potential mechanisms driving the amino acid auxotrophy of a Sphingomonas haloaromaticamans strain degrading the fungicide ortho-phenylphenol (OPP) and provided further verification for the identified mechanisms via in vitro bacterial assays. The analysis identified potential gaps in the biosynthesis of isoleucine, phenylalanine and tyrosine, while methionine biosynthesis was potentially effective, relying though in the presence of B12. Supplementation of the bacterium with the four amino acids in all possible combinations rescued its degrading capacity only with methionine. Genome sequence-based metabolic reconstruction and analysis suggested that the bacterium was incapable of de novo biosynthesis of B12 (missing genes for the construction of the corrin ring) but carried a complete salvage pathway for corrinoids uptake from the environment, transmembrane transportation and biosynthesis of B12. In line with this the bacterium maintained its degrading capacity and growth when supplied with environmentally relevant B12 concentrations (i.e., 0.1 ng ml–1). Using genome-based metabolic reconstruction and in vitro testing we unraveled the mechanism driving the auxotrophy of a pesticide-degrading S. haloaromaticamans. Further studies will investigate the corrinoids preferences of S. haloaromaticamans for optimum growth and OPP degradation.
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Affiliation(s)
- Chiara Perruchon
- Laboratory of Plant and Environmental Biotechnology, Department of Biochemistry and Biotechnology, University of Thessaly, Larissa, Greece
| | - Sotirios Vasileiadis
- Laboratory of Plant and Environmental Biotechnology, Department of Biochemistry and Biotechnology, University of Thessaly, Larissa, Greece
| | - Evangelia S Papadopoulou
- Laboratory of Plant and Environmental Biotechnology, Department of Biochemistry and Biotechnology, University of Thessaly, Larissa, Greece
| | - Dimitrios G Karpouzas
- Laboratory of Plant and Environmental Biotechnology, Department of Biochemistry and Biotechnology, University of Thessaly, Larissa, Greece
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14
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Flexible Cobamide Metabolism in Clostridioides ( Clostridium) difficile 630 Δ erm. J Bacteriol 2020; 202:JB.00584-19. [PMID: 31685533 DOI: 10.1128/jb.00584-19] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2019] [Accepted: 10/26/2019] [Indexed: 01/05/2023] Open
Abstract
Clostridioides (Clostridium) difficile is an opportunistic pathogen known for its ability to colonize the human gut under conditions of dysbiosis. Several aspects of its carbon and amino acid metabolism have been investigated, but its cobamide (vitamin B12 and related cofactors) metabolism remains largely unexplored. C. difficile has seven predicted cobamide-dependent pathways encoded in its genome in addition to a nearly complete cobamide biosynthesis pathway and a cobamide uptake system. To address the importance of cobamides to C. difficile, we studied C. difficile 630 Δerm and mutant derivatives under cobamide-dependent conditions in vitro Our results show that C. difficile can use a surprisingly diverse array of cobamides for methionine and deoxyribonucleotide synthesis and can use alternative metabolites or enzymes, respectively, to bypass these cobamide-dependent processes. C. difficile 630 Δerm produces the cobamide pseudocobalamin when provided the early precursor 5-aminolevulinic acid or the late intermediate cobinamide (Cbi) and produces other cobamides if provided an alternative lower ligand. The ability of C. difficile 630 Δerm to take up cobamides and Cbi at micromolar or lower concentrations requires the transporter BtuFCD. Genomic analysis revealed genetic variations in the btuFCD loci of different C. difficile strains, which may result in differences in the ability to take up cobamides and Cbi. These results together demonstrate that, like other aspects of its physiology, cobamide metabolism in C. difficile is versatile.IMPORTANCE The ability of the opportunistic pathogen Clostridioides difficile to cause disease is closely linked to its propensity to adapt to conditions created by dysbiosis of the human gut microbiota. The cobamide (vitamin B12) metabolism of C. difficile has been underexplored, although it has seven metabolic pathways that are predicted to require cobamide-dependent enzymes. Here, we show that C. difficile cobamide metabolism is versatile, as it can use a surprisingly wide variety of cobamides and has alternative functions that can bypass some of its cobamide requirements. Furthermore, C. difficile does not synthesize cobamides de novo but produces them when given cobamide precursors. A better understanding of C. difficile cobamide metabolism may lead to new strategies to treat and prevent C. difficile-associated disease.
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15
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Torres AC, Elean M, Hebert EM, Saavedra L, Taranto MP. Metabolic shift in the production of corrinoid compounds by Lactobacillus coryniformis in the absence of purines. Biochimie 2020; 168:185-189. [DOI: 10.1016/j.biochi.2019.11.003] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2019] [Accepted: 11/05/2019] [Indexed: 11/25/2022]
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16
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Ma AT, Tyrell B, Beld J. Specificity of cobamide remodeling, uptake and utilization in Vibrio cholerae. Mol Microbiol 2019; 113:89-102. [PMID: 31609521 DOI: 10.1111/mmi.14402] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/11/2019] [Indexed: 12/11/2022]
Abstract
Cobamides are a group of compounds including vitamin B12 that can vary at the lower base position of the nucleotide loop. They are synthesized de novo by only a subset of prokaryotes, but some organisms encode partial biosynthesis pathways for converting one variant to another (remodeling) or completing biosynthesis from an intermediate (corrinoid salvaging). Here, we explore the cobamide specificity in Vibrio cholerae through examination of three natural variants representing major cobamide groups: commercially available cobalamin, and isolated pseudocobalamin and p-cresolylcobamide. We show that BtuB, the outer membrane corrinoid transporter, mediates the uptake of all three variants and the intermediate cobinamide. Our previous work suggested that V. cholerae could convert pseudocobalamin produced by cyanobacteria into cobalamin. In this work, cobamide specificity in V. cholerae is demonstrated by remodeling of pseudocobalamin and salvaging of cobinamide to produce cobalamin. Cobamide remodeling in V. cholerae is distinct from the canonical pathway requiring amidohydrolase CbiZ, and heterologous expression of V. cholerae CobS was sufficient for remodeling. Furthermore, function of V. cholerae cobamide-dependent methionine synthase MetH was robustly supported by cobalamin and p-cresolylcobamide, but not pseudocobalamin. Notably, the inability of V. cholerae to produce and utilize pseudocobalamin contrasts with enteric bacteria like Salmonella.
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Affiliation(s)
- Amy T Ma
- Department of Microbiology and Immunology, Drexel University College of Medicine, Philadelphia, PA, 19102, USA
| | - Breanna Tyrell
- Department of Microbiology and Immunology, Drexel University College of Medicine, Philadelphia, PA, 19102, USA
| | - Joris Beld
- Department of Microbiology and Immunology, Drexel University College of Medicine, Philadelphia, PA, 19102, USA
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17
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Sokolovskaya OM, Mok KC, Park JD, Tran JLA, Quanstrom KA, Taga ME. Cofactor Selectivity in Methylmalonyl Coenzyme A Mutase, a Model Cobamide-Dependent Enzyme. mBio 2019; 10:e01303-19. [PMID: 31551329 PMCID: PMC6759758 DOI: 10.1128/mbio.01303-19] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2019] [Accepted: 08/23/2019] [Indexed: 12/25/2022] Open
Abstract
Cobamides, a uniquely diverse family of enzyme cofactors related to vitamin B12, are produced exclusively by bacteria and archaea but used in all domains of life. While it is widely accepted that cobamide-dependent organisms require specific cobamides for their metabolism, the biochemical mechanisms that make cobamides functionally distinct are largely unknown. Here, we examine the effects of cobamide structural variation on a model cobamide-dependent enzyme, methylmalonyl coenzyme A (CoA) mutase (MCM). The in vitro binding affinity of MCM for cobamides can be dramatically influenced by small changes in the structure of the lower ligand of the cobamide, and binding selectivity differs between bacterial orthologs of MCM. In contrast, variations in the lower ligand have minor effects on MCM catalysis. Bacterial growth assays demonstrate that cobamide requirements of MCM in vitro largely correlate with in vivo cobamide dependence. This result underscores the importance of enzyme selectivity in the cobamide-dependent physiology of bacteria.IMPORTANCE Cobamides, including vitamin B12, are enzyme cofactors used by organisms in all domains of life. Cobamides are structurally diverse, and microbial growth and metabolism vary based on cobamide structure. Understanding cobamide preference in microorganisms is important given that cobamides are widely used and appear to mediate microbial interactions in host-associated and aquatic environments. Until now, the biochemical basis for cobamide preferences was largely unknown. In this study, we analyzed the effects of the structural diversity of cobamides on a model cobamide-dependent enzyme, methylmalonyl-CoA mutase (MCM). We found that very small changes in cobamide structure could dramatically affect the binding affinity of cobamides to MCM. Strikingly, cobamide-dependent growth of a model bacterium, Sinorhizobium meliloti, largely correlated with the cofactor binding selectivity of S. meliloti MCM, emphasizing the importance of cobamide-dependent enzyme selectivity in bacterial growth and cobamide-mediated microbial interactions.
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Affiliation(s)
- Olga M Sokolovskaya
- Department of Plant & Microbial Biology, University of California Berkeley, Berkeley, California, USA
- Department of Chemistry, University of California Berkeley, Berkeley, California, USA
| | - Kenny C Mok
- Department of Plant & Microbial Biology, University of California Berkeley, Berkeley, California, USA
| | - Jong Duk Park
- Department of Plant & Microbial Biology, University of California Berkeley, Berkeley, California, USA
| | - Jennifer L A Tran
- Department of Plant & Microbial Biology, University of California Berkeley, Berkeley, California, USA
| | - Kathryn A Quanstrom
- Department of Plant & Microbial Biology, University of California Berkeley, Berkeley, California, USA
| | - Michiko E Taga
- Department of Plant & Microbial Biology, University of California Berkeley, Berkeley, California, USA
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18
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Schubert T, von Reuß SH, Kunze C, Paetz C, Kruse S, Brand‐Schön P, Nelly AM, Nüske J, Diekert G. Guided cobamide biosynthesis for heterologous production of reductive dehalogenases. Microb Biotechnol 2019; 12:346-359. [PMID: 30549216 PMCID: PMC6389850 DOI: 10.1111/1751-7915.13339] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2018] [Revised: 10/23/2018] [Accepted: 10/30/2018] [Indexed: 12/01/2022] Open
Abstract
Cobamides (Cbas) are essential cofactors of reductive dehalogenases (RDases) in organohalide-respiring bacteria (OHRB). Changes in the Cba structure can influence RDase function. Here, we report on the cofactor versatility or selectivity of Desulfitobacterium RDases produced either in the native organism or heterologously. The susceptibility of Desulfitobacterium hafniense strain DCB-2 to guided Cba biosynthesis (i.e. incorporation of exogenous Cba lower ligand base precursors) was analysed. Exogenous benzimidazoles, azabenzimidazoles and 4,5-dimethylimidazole were incorporated by the organism into Cbas. When the type of Cba changed, no effect on the turnover rate of the 3-chloro-4-hydroxy-phenylacetate-converting enzyme RdhA6 and the 3,5-dichlorophenol-dehalogenating enzyme RdhA3 was observed. The impact of the amendment of Cba lower ligand precursors on RDase function was also investigated in Shimwellia blattae, the Cba producer used for the heterologous production of Desulfitobacterium RDases. The recombinant tetrachloroethene RDase (PceAY51 ) appeared to be non-selective towards different Cbas. However, the functional production of the 1,2-dichloroethane-dihaloeliminating enzyme (DcaA) of Desulfitobacterium dichloroeliminans was completely prevented in cells producing 5,6-dimethylbenzimidazolyl-Cba, but substantially enhanced in cells that incorporated 5-methoxybenzimidazole into the Cba cofactor. The results of the study indicate the utilization of a range of different Cbas by Desulfitobacterium RDases with selected representatives apparently preferring distinct Cbas.
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Affiliation(s)
- Torsten Schubert
- Department of Applied and Ecological MicrobiologyInstitute of MicrobiologyFriedrich Schiller UniversityPhilosophenweg 12D‐07743JenaGermany
| | - Stephan H. von Reuß
- Department of Bioorganic ChemistryMax Planck Institute for Chemical EcologyHans‐Knöll‐Straße 8D‐07745JenaGermany
- Present address:
Laboratory for Bioanalytical ChemistryInstitute of ChemistryUniversity of NeuchâtelAvenue de Bellevaux 512000NeuchâtelSwitzerland
| | - Cindy Kunze
- Department of Applied and Ecological MicrobiologyInstitute of MicrobiologyFriedrich Schiller UniversityPhilosophenweg 12D‐07743JenaGermany
- Present address:
DECHEMA‐ForschungsinstitutTheodor‐Heuss‐Allee 25D‐60486Frankfurt am MainGermany
| | - Christian Paetz
- Research Group Biosynthesis/NMRMax Planck Institute for Chemical EcologyHans‐Knöll‐Straße 8D‐07745JenaGermany
| | - Stefan Kruse
- Department of Applied and Ecological MicrobiologyInstitute of MicrobiologyFriedrich Schiller UniversityPhilosophenweg 12D‐07743JenaGermany
| | - Peggy Brand‐Schön
- Department of Applied and Ecological MicrobiologyInstitute of MicrobiologyFriedrich Schiller UniversityPhilosophenweg 12D‐07743JenaGermany
| | - Anita Mac Nelly
- Department of Applied and Ecological MicrobiologyInstitute of MicrobiologyFriedrich Schiller UniversityPhilosophenweg 12D‐07743JenaGermany
| | - Jörg Nüske
- Department of Applied and Ecological MicrobiologyInstitute of MicrobiologyFriedrich Schiller UniversityPhilosophenweg 12D‐07743JenaGermany
| | - Gabriele Diekert
- Department of Applied and Ecological MicrobiologyInstitute of MicrobiologyFriedrich Schiller UniversityPhilosophenweg 12D‐07743JenaGermany
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19
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Jeter VL, Mattes TA, Beattie NR, Escalante-Semerena JC. A New Class of Phosphoribosyltransferases Involved in Cobamide Biosynthesis Is Found in Methanogenic Archaea and Cyanobacteria. Biochemistry 2019; 58:951-964. [PMID: 30640434 DOI: 10.1021/acs.biochem.8b01253] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
Cobamides are coenzymes used by cells from all domains of life but made de novo by only some bacteria and archaea. The last steps of the cobamide biosynthetic pathway activate the corrin ring and the lower ligand base, condense the activated intermediates, and dephosphorylate the product prior to the release of the biologically active coenzyme. In bacteria, a phosphoribosyltransferase (PRTase) enyzme activates the base into its α-mononucleotide. The enzyme from Salmonella enterica ( SeCobT) has been extensively biochemically and structurally characterized. The crystal structure of the putative PRTase from the archaeum Methanocaldococcus jannaschii ( MjCobT) is known, but its function has not been validated. Here we report the in vivo and in vitro characterization of MjCobT. In vivo, in vitro, and phylogenetic data reported here show that MjCobT belongs to a new class of NaMN-dependent PRTases. We also show that the Synechococcus sp. WH7803 CobT protein has PRTase activity in vivo. Lastly, results of isothermal titration calorimetry and analytical ultracentrifugation analysis show that the biologically active form of MjCobT is a dimer, not a trimer, as suggested by its crystal structure.
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20
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Uneven distribution of cobamide biosynthesis and dependence in bacteria predicted by comparative genomics. ISME JOURNAL 2018; 13:789-804. [PMID: 30429574 PMCID: PMC6461909 DOI: 10.1038/s41396-018-0304-9] [Citation(s) in RCA: 118] [Impact Index Per Article: 19.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/07/2018] [Revised: 09/14/2018] [Accepted: 10/04/2018] [Indexed: 11/08/2022]
Abstract
The vitamin B12 family of cofactors known as cobamides are essential for a variety of microbial metabolisms. We used comparative genomics of 11,000 bacterial species to analyze the extent and distribution of cobamide production and use across bacteria. We find that 86% of bacteria in this data set have at least one of 15 cobamide-dependent enzyme families, but only 37% are predicted to synthesize cobamides de novo. The distribution of cobamide biosynthesis and use vary at the phylum level. While 57% of Actinobacteria are predicted to biosynthesize cobamides, only 0.6% of Bacteroidetes have the complete pathway, yet 96% of species in this phylum have cobamide-dependent enzymes. The form of cobamide produced by the bacteria could be predicted for 58% of cobamide-producing species, based on the presence of signature lower ligand biosynthesis and attachment genes. Our predictions also revealed that 17% of bacteria have partial biosynthetic pathways, yet have the potential to salvage cobamide precursors. Bacteria with a partial cobamide biosynthesis pathway include those in a newly defined, experimentally verified category of bacteria lacking the first step in the biosynthesis pathway. These predictions highlight the importance of cobamide and cobamide precursor salvaging as examples of nutritional dependencies in bacteria.
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21
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Torres AC, Vannini V, Font G, Saavedra L, Taranto MP. Novel Pathway for Corrinoid Compounds Production in Lactobacillus. Front Microbiol 2018; 9:2256. [PMID: 30319575 PMCID: PMC6167548 DOI: 10.3389/fmicb.2018.02256] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2018] [Accepted: 09/05/2018] [Indexed: 12/22/2022] Open
Abstract
Vitamin B12 or cobalamin is an essential metabolite for humans, which makes it an interesting compound for many research groups that focus in different producer-strains synthesis pathways. In this work, we report the influence of key intermediaries for cobalamin synthesis added to the culture medium in two Lactobacillus (L.) strains, L. reuteri CRL 1098 and L. coryniformis CRL 1001. Here, we report that addition of Co2+ and 5,6-dimethylbenzimidazole increased the corrinoid compounds production in both strains while addition of L-threonine increased only the corrinoid compounds production by CRL 1001 strain. Then, we purified and characterized by LC-MS the corrinoid compounds obtained. Physiological studies besides in silico analysis revealed that L. reuteri CRL 1098 and L. coryniformis CRL 1001 follow different pathways for the last steps of the corrinoid compounds synthesis.
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Affiliation(s)
- Andrea Carolina Torres
- Centro de Referencia para Lactobacilos (CERELA)-CONICET, San Miguel de Tucumán, Argentina
| | - Verónica Vannini
- Centro de Referencia para Lactobacilos (CERELA)-CONICET, San Miguel de Tucumán, Argentina
| | - Graciela Font
- Centro de Referencia para Lactobacilos (CERELA)-CONICET, San Miguel de Tucumán, Argentina
| | - Lucila Saavedra
- Centro de Referencia para Lactobacilos (CERELA)-CONICET, San Miguel de Tucumán, Argentina
| | - María Pía Taranto
- Centro de Referencia para Lactobacilos (CERELA)-CONICET, San Miguel de Tucumán, Argentina
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22
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Chittim CL, Irwin SM, Balskus EP. Deciphering Human Gut Microbiota-Nutrient Interactions: A Role for Biochemistry. Biochemistry 2018; 57:2567-2577. [PMID: 29669199 DOI: 10.1021/acs.biochem.7b01277] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
The human gut contains trillions of microorganisms that play a central role in many aspects of host biology, including the provision of key nutrients from the diet. However, our appreciation of how gut microbes and their extensive metabolic capabilities affect the nutritional status of the human host is in its infancy. In this Perspective, we highlight how recent efforts to elucidate the biochemical basis for gut microbial metabolism of dietary components are reshaping our view of these organisms' roles in host nutrition. Gaining a molecular understanding of gut microbe-nutrient interactions will enhance our knowledge of how diet affects host health and disease, ultimately enabling personalized nutrition and therapeutics.
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Affiliation(s)
- Carina L Chittim
- Department of Chemistry and Chemical Biology , Harvard University , 12 Oxford Street , Cambridge , Massachusetts 02138 , United States
| | - Stephania M Irwin
- Department of Chemistry and Chemical Biology , Harvard University , 12 Oxford Street , Cambridge , Massachusetts 02138 , United States
| | - Emily P Balskus
- Department of Chemistry and Chemical Biology , Harvard University , 12 Oxford Street , Cambridge , Massachusetts 02138 , United States
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23
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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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24
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Ghazi Z, Jahanshahi S, Li Y. RiboFACSeq: A new method for investigating metabolic and transport pathways in bacterial cells by combining a riboswitch-based sensor, fluorescence-activated cell sorting and next-generation sequencing. PLoS One 2017; 12:e0188399. [PMID: 29211762 PMCID: PMC5718407 DOI: 10.1371/journal.pone.0188399] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2017] [Accepted: 11/06/2017] [Indexed: 12/02/2022] Open
Abstract
The elucidation of the cellular processes involved in vitamin and cofactor biosynthesis is a challenging task. The conventional approaches to these investigations rely on the discovery and purification of the products (i.e proteins and metabolites) of a particular transport or biosynthetic pathway, prior to their subsequent analysis. However, the purification of low-abundance proteins or metabolites is a formidable undertaking that presents considerable technical challenges. As a solution, we present an alternative approach to such studies that circumvents the purification step. The proposed approach takes advantage of: (1) the molecular detection capabilities of a riboswitch-based sensor to detect the cellular levels of its cognate molecule, as a means to probe the integrity of the transport and biosynthetic pathways of the target molecule in cells, (2) the high-throughput screening ability of fluorescence-activated cell sorters to isolate cells in which only these specific pathways are disrupted, and (3) the ability of next-generation sequencing to quickly identify the genes of the FACS-sorted populations. This approach was named “RiboFACSeq”. Following their identification by RiboFACSeq, the role of these genes in the presumed pathway needs to be verified through appropriate functional assays. To demonstrate the utility of our approach, an adenosylcobalamin (AdoCbl)-responsive riboswitch-based sensor was used in this study to demonstrate that RiboFACSeq can be used to track and sort cells carrying genetic mutations in known AdoCbl transport and biosynthesis genes with desirable sensitivity and specificity. This method could potentially be used to elucidate any pathway of interest, as long as a suitable riboswitch-based sensor can be created. We believe that RiboFACSeq would be especially useful for the elucidation of biological pathways in which the proteins and/or their metabolites are present at very low physiological concentrations in cells, as is the case with vitamin and cofactor biosynthesis.
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Affiliation(s)
- Zohaib Ghazi
- Department of Biochemistry and Biomedical Sciences, McMaster University, Hamilton, Ontario, Canada
| | - Shahrzad Jahanshahi
- School of Biomedical Engineering, McMaster University, Hamilton, Ontario, Canada
| | - Yingfu Li
- Department of Biochemistry and Biomedical Sciences, McMaster University, Hamilton, Ontario, Canada
- School of Biomedical Engineering, McMaster University, Hamilton, Ontario, Canada
- * E-mail:
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25
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Yan J, Bi M, Bourdon AK, Farmer AT, Wang PH, Molenda O, Quaile AT, Jiang N, Yang Y, Yin Y, Şimşir B, Campagna SR, Edwards EA, Löffler FE. Purinyl-cobamide is a native prosthetic group of reductive dehalogenases. Nat Chem Biol 2017; 14:8-14. [PMID: 29106396 PMCID: PMC6081238 DOI: 10.1038/nchembio.2512] [Citation(s) in RCA: 46] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2017] [Accepted: 10/02/2017] [Indexed: 01/21/2023]
Abstract
Cobamides such as vitamin B12 are structurally conserved, cobalt-containing tetrapyrrole biomolecules that have essential biochemical functions in all domains of life. In organohalide respiration, a vital biological process for the global cycling of natural and anthropogenic organohalogens, cobamides are the requisite prosthetic groups for carbon-halogen bond-cleaving reductive dehalogenases. This study reports the biosynthesis of a new cobamide with unsubstituted purine as the lower base and assigns unsubstituted purine a biological function by demonstrating that Coα-purinyl-cobamide (purinyl-Cba) is the native prosthetic group in catalytically active tetrachloroethene reductive dehalogenases of Desulfitobacterium hafniense. Cobamides featuring different lower bases are not functionally equivalent, and purinyl-Cba elicits different physiological responses in corrinoid-auxotrophic, organohalide-respiring bacteria. Given that cobamide-dependent enzymes catalyze key steps in essential metabolic pathways, the discovery of a novel cobamide structure and the realization that lower bases can effectively modulate enzyme activities generate opportunities to manipulate functionalities of microbiomes.
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Affiliation(s)
- Jun Yan
- Department of Microbiology, University of Tennessee, Knoxville, Tennessee, USA.,Key Laboratory of Pollution Ecology and Environmental Engineering, Institute of Applied Ecology, Chinese Academy of Sciences, Shenyang, Liaoning, P.R. China.,Center for Environmental Biotechnology, University of Tennessee, Knoxville, Tennessee, USA.,Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee, USA.,Joint Institute for Biological Sciences (JIBS), Oak Ridge National Laboratory, Oak Ridge, Tennessee, USA
| | - Meng Bi
- Department of Microbiology, University of Tennessee, Knoxville, Tennessee, USA
| | - Allen K Bourdon
- Department of Chemistry, University of Tennessee, Knoxville, Tennessee, USA
| | - Abigail T Farmer
- Department of Chemistry, University of Tennessee, Knoxville, Tennessee, USA
| | - Po-Hsiang Wang
- Department of Chemical Engineering and Applied Chemistry, University of Toronto, Toronto, Ontario, Canada
| | - Olivia Molenda
- Department of Chemical Engineering and Applied Chemistry, University of Toronto, Toronto, Ontario, Canada
| | - Andrew T Quaile
- Department of Chemical Engineering and Applied Chemistry, University of Toronto, Toronto, Ontario, Canada
| | - Nannan Jiang
- Center for Environmental Biotechnology, University of Tennessee, Knoxville, Tennessee, USA.,Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee, USA.,Joint Institute for Biological Sciences (JIBS), Oak Ridge National Laboratory, Oak Ridge, Tennessee, USA.,Bredesen Center for Interdisciplinary Research and Graduate Education, University of Tennessee, Knoxville, Tennessee, USA
| | - Yi Yang
- Center for Environmental Biotechnology, University of Tennessee, Knoxville, Tennessee, USA.,Department of Civil and Environmental Engineering, University of Tennessee, Knoxville, Tennessee, USA
| | - Yongchao Yin
- Department of Microbiology, University of Tennessee, Knoxville, Tennessee, USA
| | - Burcu Şimşir
- Center for Environmental Biotechnology, University of Tennessee, Knoxville, Tennessee, USA.,Department of Civil and Environmental Engineering, University of Tennessee, Knoxville, Tennessee, USA
| | - Shawn R Campagna
- Department of Chemistry, University of Tennessee, Knoxville, Tennessee, USA
| | - Elizabeth A Edwards
- Department of Chemical Engineering and Applied Chemistry, University of Toronto, Toronto, Ontario, Canada
| | - Frank E Löffler
- Department of Microbiology, University of Tennessee, Knoxville, Tennessee, USA.,Center for Environmental Biotechnology, University of Tennessee, Knoxville, Tennessee, USA.,Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee, USA.,Joint Institute for Biological Sciences (JIBS), Oak Ridge National Laboratory, Oak Ridge, Tennessee, USA.,Bredesen Center for Interdisciplinary Research and Graduate Education, University of Tennessee, Knoxville, Tennessee, USA.,Department of Civil and Environmental Engineering, University of Tennessee, Knoxville, Tennessee, USA.,Department of Biosystems Engineering and Soil Science, University of Tennessee, Knoxville, Tennessee, USA
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26
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An Amoebal Grazer of Cyanobacteria Requires Cobalamin Produced by Heterotrophic Bacteria. Appl Environ Microbiol 2017; 83:AEM.00035-17. [PMID: 28283521 DOI: 10.1128/aem.00035-17] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2017] [Accepted: 03/03/2017] [Indexed: 01/22/2023] Open
Abstract
Amoebae are unicellular eukaryotes that consume microbial prey through phagocytosis, playing a role in shaping microbial food webs. Many amoebal species can be cultivated axenically in rich media or monoxenically with a single bacterial prey species. Here, we characterize heterolobosean amoeba LPG3, a recent natural isolate, which is unable to grow on unicellular cyanobacteria, its primary food source, in the absence of a heterotrophic bacterium, a Pseudomonas species coisolate. To investigate the molecular basis of this requirement for heterotrophic bacteria, we performed a screen using the defined nonredundant transposon library of Vibrio cholerae, which implicated genes in corrinoid uptake and biosynthesis. Furthermore, cobalamin synthase deletion mutations in V. cholerae and the Pseudomonas species coisolate do not support the growth of amoeba LPG3 on cyanobacteria. While cyanobacteria are robust producers of a corrinoid variant called pseudocobalamin, this variant does not support the growth of amoeba LPG3. Instead, we show that it requires cobalamin that is produced by the Pseudomonas species coisolate. The diversity of eukaryotes utilizing corrinoids is poorly understood, and this amoebal corrinoid auxotroph serves as a model for examining predator-prey interactions and micronutrient transfer in bacterivores underpinning microbial food webs.IMPORTANCE Cyanobacteria are important primary producers in aquatic environments, where they are grazed upon by a variety of phagotrophic protists and, hence, have an impact on nutrient flux at the base of microbial food webs. Here, we characterize amoebal isolate LPG3, which consumes cyanobacteria as its primary food source but also requires heterotrophic bacteria as a source of corrinoid vitamins. Amoeba LPG3 specifically requires the corrinoid variant produced by heterotrophic bacteria and cannot grow on cyanobacteria alone, as they produce a different corrinoid variant. This same corrinoid specificity is also exhibited by other eukaryotes, including humans and algae. This amoebal model system allows us to dissect predator-prey interactions to uncover factors that may shape microbial food webs while also providing insight into corrinoid specificity in eukaryotes.
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Fang H, Kang J, Zhang D. Microbial production of vitamin B 12: a review and future perspectives. Microb Cell Fact 2017; 16:15. [PMID: 28137297 PMCID: PMC5282855 DOI: 10.1186/s12934-017-0631-y] [Citation(s) in RCA: 182] [Impact Index Per Article: 26.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2016] [Accepted: 01/20/2017] [Indexed: 12/21/2022] Open
Abstract
Vitamin B12 is an essential vitamin that is widely used in medical and food industries. Vitamin B12 biosynthesis is confined to few bacteria and archaea, and as such its production relies on microbial fermentation. Rational strain engineering is dependent on efficient genetic tools and a detailed knowledge of metabolic pathways, regulation of which can be applied to improve product yield. Recent advances in synthetic biology and metabolic engineering have been used to efficiently construct many microbial chemical factories. Many published reviews have probed the vitamin B12 biosynthetic pathway. To maximize the potential of microbes for vitamin B12 production, new strategies and tools are required. In this review, we provide a comprehensive understanding of advances in the microbial production of vitamin B12, with a particular focus on establishing a heterologous host for the vitamin B12 production, as well as on strategies and tools that have been applied to increase microbial cobalamin production. Several worthy strategies employed for other products are also included.
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Affiliation(s)
- Huan Fang
- Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin, 300308 China
- Key Laboratory of Systems Microbial Biotechnology, Chinese Academy of Sciences, Tianjin, 300308 China
- University of Chinese Academy of Sciences, Beijing, 100049 China
| | - Jie Kang
- Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin, 300308 China
- College of Biotechnology and Food Science, Tianjin University of Commerce, Tianjin, 300134 China
| | - Dawei Zhang
- Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin, 300308 China
- Key Laboratory of Systems Microbial Biotechnology, Chinese Academy of Sciences, Tianjin, 300308 China
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Refined experimental annotation reveals conserved corrinoid autotrophy in chloroform-respiring Dehalobacter isolates. ISME JOURNAL 2016; 11:626-640. [PMID: 27898054 DOI: 10.1038/ismej.2016.158] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/30/2016] [Revised: 09/25/2016] [Accepted: 10/07/2016] [Indexed: 11/08/2022]
Abstract
Two novel chlorinated alkane-respiring Dehalobacter restrictus strains CF and DCA were isolated from the same enrichment culture, ACT-3, and characterized. The closed genomes of these highly similar sister strains were previously assembled from metagenomic sequence data and annotated. The isolation of the strains enabled experimental verification of predicted annotations, particularly focusing on irregularities or predicted gaps in central metabolic pathways and cofactor biosynthesis. Similar to D. restrictus strain PER-K23, strains CF and DCA require arginine, histidine and threonine for growth, although the corresponding biosynthesis pathways are predicted to be functional. Using strain CF to experimentally verify annotations, we determined that the predicted defective serine biosynthesis pathway can be rescued with a promiscuous serine hydroxymethyltransferase. Strain CF grew without added thiamine although the thiamine biosynthesis pathway is predicted to be absent; intracellular thiamine diphosphate, the cofactor of carboxylases in central metabolism, was not detected in cell extracts. Thus, strain CF may use amino acids to replenish central metabolites, portending entangled metabolite exchanges in ACT-3. Consistent with annotation, strain CF possesses a functional corrinoid biosynthesis pathway, demonstrated by increasing corrinoid content during growth and guided cobalamin biosynthesis in corrinoid-free medium. Chloroform toxicity to corrinoid-producing methanogens and acetogens may drive the conservation of corrinoid autotrophy in Dehalobacter strains. Heme detection in strain CF cell extracts suggests the 'archaeal' heme biosynthesis pathway also functions in anaerobic Firmicutes. This study reinforces the importance of incorporating enzyme promiscuity and cofactor availability in genome-scale functional predictions and identifies essential nutrient interdependencies in anaerobic dechlorinating microbial communities.
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Abreu NA, Taga ME. Decoding molecular interactions in microbial communities. FEMS Microbiol Rev 2016; 40:648-63. [PMID: 27417261 DOI: 10.1093/femsre/fuw019] [Citation(s) in RCA: 54] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/06/2016] [Indexed: 12/21/2022] Open
Abstract
Microbial communities govern numerous fundamental processes on earth. Discovering and tracking molecular interactions among microbes is critical for understanding how single species and complex communities impact their associated host or natural environment. While recent technological developments in DNA sequencing and functional imaging have led to new and deeper levels of understanding, we are limited now by our inability to predict and interpret the intricate relationships and interspecies dependencies within these communities. In this review, we highlight the multifaceted approaches investigators have taken within their areas of research to decode interspecies molecular interactions that occur between microbes. Understanding these principles can give us greater insight into ecological interactions in natural environments and within synthetic consortia.
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Affiliation(s)
- Nicole A Abreu
- Department of Plant and Microbial Biology, University of California, Berkeley, CA 94720-3102, USA
| | - Michiko E Taga
- Department of Plant and Microbial Biology, University of California, Berkeley, CA 94720-3102, USA
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Deptula P, Kylli P, Chamlagain B, Holm L, Kostiainen R, Piironen V, Savijoki K, Varmanen P. BluB/CobT2 fusion enzyme activity reveals mechanisms responsible for production of active form of vitamin B₁₂ by Propionibacterium freudenreichii. Microb Cell Fact 2015; 14:186. [PMID: 26597297 PMCID: PMC4657239 DOI: 10.1186/s12934-015-0363-9] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2015] [Accepted: 10/18/2015] [Indexed: 01/02/2023] Open
Abstract
Background Propionibacterium freudenreichii is a food grade bacterium that has gained attention as a producer of appreciable amounts of cobalamin, a cobamide with activity of vitamin B12. Production of active form of vitamin is a prerequisite for attempts to naturally fortify foods with B12 by microbial fermentation. Active vitamin B12 is distinguished from the pseudovitamin by the presence of 5,6-dimethylbenzimidazole (DMBI) as the lower ligand. Genomic data indicate that P. freudenreichii possesses a fusion gene, bluB/cobT2, coding for a predicted phosphoribosyltransferase/nitroreductase, which is presumably involved in production of vitamin B12. Understanding the mechanisms affecting the synthesis of different vitamin forms is useful for rational strain selection and essential for engineering of strains with improved B12 production properties. Results Here, we investigated the activity of heterologously expressed and purified fusion enzyme BluB/CobT2. Our results show that BluB/CoBT2 is responsible for the biosynthesis of the DMBI base and its activation into α-ribazole phosphate, preparing it for attachment as the lower ligand of cobalamin. The fusion enzyme was found to be efficient in metabolite channeling and the enzymes’ inability to react with adenine, a lower ligand present in the pseudovitamin, revealed a mechanism favoring the production of the active form of the vitamin. P. freudenreichii did not produce cobalamin under strictly anaerobic conditions, confirming the requirement of oxygen for DMBI synthesis. In vivo experiments also revealed a clear preference for incorporating DMBI over adenine into cobamide under both microaerobic and anaerobic conditions. Conclusions The herein described BluB/CobT2 is responsible for the production and activation of DMBI. Fusing those two activities results in high pressure towards production of the true vitamin B12 by efficiently activating DMBI formed within the same enzymatic complex. This indicates that BluB/CobT2 is the crucial enzyme in the B12 biosynthetic pathway of P. freudenreichii. The GRAS organism status and the preference for synthesizing active vitamin form make P. freudenreichii a unique candidate for the in situ production of vitamin B12 within food products. Electronic supplementary material The online version of this article (doi:10.1186/s12934-015-0363-9) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Paulina Deptula
- Department of Food and Environmental Sciences, University of Helsinki, 00014, Helsinki, Finland.
| | - Petri Kylli
- Division of Pharmaceutical Chemistry and Technology, University of Helsinki, 00014, Helsinki, Finland.
| | - Bhawani Chamlagain
- Department of Food and Environmental Sciences, University of Helsinki, 00014, Helsinki, Finland.
| | - Liisa Holm
- Institute of Biotechnology, University of Helsinki, 00014, Helsinki, Finland.
| | - Risto Kostiainen
- Division of Pharmaceutical Chemistry and Technology, University of Helsinki, 00014, Helsinki, Finland.
| | - Vieno Piironen
- Department of Food and Environmental Sciences, University of Helsinki, 00014, Helsinki, Finland.
| | - Kirsi Savijoki
- Department of Food and Environmental Sciences, University of Helsinki, 00014, Helsinki, Finland.
| | - Pekka Varmanen
- Department of Food and Environmental Sciences, University of Helsinki, 00014, Helsinki, Finland.
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Supplementing lactating dairy cows with a vitamin B12 precursor, 5,6-dimethylbenzimidazole, increases the apparent ruminal synthesis of vitamin B12. Animal 2015; 9:67-75. [DOI: 10.1017/s1751731114002201] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022] Open
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Crofts TS, Hazra AB, Tran JLA, Sokolovskaya OM, Osadchiy V, Ad O, Pelton J, Bauer S, Taga ME. Regiospecific Formation of Cobamide Isomers Is Directed by CobT. Biochemistry 2014; 53:7805-15. [DOI: 10.1021/bi501147d] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Terence S. Crofts
- Department of Plant and Microbial Biology, ∥Department of Chemistry, ⊥QB3 Institute, and #Energy Biosciences Institute, University of California, Berkeley, United States
| | - Amrita B. Hazra
- Department of Plant and Microbial Biology, ∥Department of Chemistry, ⊥QB3 Institute, and #Energy Biosciences Institute, University of California, Berkeley, United States
| | - Jennifer LA Tran
- Department of Plant and Microbial Biology, ∥Department of Chemistry, ⊥QB3 Institute, and #Energy Biosciences Institute, University of California, Berkeley, United States
| | - Olga M. Sokolovskaya
- Department of Plant and Microbial Biology, ∥Department of Chemistry, ⊥QB3 Institute, and #Energy Biosciences Institute, University of California, Berkeley, United States
| | - Vadim Osadchiy
- Department of Plant and Microbial Biology, ∥Department of Chemistry, ⊥QB3 Institute, and #Energy Biosciences Institute, University of California, Berkeley, United States
| | - Omer Ad
- Department of Plant and Microbial Biology, ∥Department of Chemistry, ⊥QB3 Institute, and #Energy Biosciences Institute, University of California, Berkeley, United States
| | - Jeffrey Pelton
- Department of Plant and Microbial Biology, ∥Department of Chemistry, ⊥QB3 Institute, and #Energy Biosciences Institute, University of California, Berkeley, United States
| | - Stefan Bauer
- Department of Plant and Microbial Biology, ∥Department of Chemistry, ⊥QB3 Institute, and #Energy Biosciences Institute, University of California, Berkeley, United States
| | - Michiko E. Taga
- Department of Plant and Microbial Biology, ∥Department of Chemistry, ⊥QB3 Institute, and #Energy Biosciences Institute, University of California, Berkeley, United States
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Crofts TS, Men Y, Alvarez-Cohen L, Taga ME. A bioassay for the detection of benzimidazoles reveals their presence in a range of environmental samples. Front Microbiol 2014; 5:592. [PMID: 25431570 PMCID: PMC4230183 DOI: 10.3389/fmicb.2014.00592] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2014] [Accepted: 10/20/2014] [Indexed: 12/13/2022] Open
Abstract
Cobamides are a family of enzyme cofactors that include vitamin B12 (cobalamin) and are produced solely by prokaryotes. Structural variability in the lower axial ligand has been observed in cobamides produced by diverse organisms. Of the three classes of lower ligands, the benzimidazoles are uniquely found in cobamides, whereas the purine and phenolic bases have additional biological functions. Many organisms acquire cobamides by salvaging and remodeling cobamides or their precursors from the environment. These processes require free benzimidazoles for incorporation as lower ligands, though the presence of benzimidazoles in the environment has not been previously investigated. Here, we report a new purification method and bioassay to measure the total free benzimidazole content of samples from microbial communities and laboratory media components. The bioassay relies on the “calcofluor-bright” phenotype of a bluB mutant of the model cobalamin-producing bacterium Sinorhizobium meliloti. The concentrations of individual benzimidazoles in these samples were measured by liquid chromatography-tandem mass spectrometry. Several benzimidazoles were detected in subpicomolar to subnanomolar concentrations in host-associated and environmental samples. In addition, benzimidazoles were found to be common contaminants of laboratory media components. These results suggest that benzimidazoles present in the environment and in laboratory media have the potential to influence microbial metabolic activities.
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Affiliation(s)
- Terence S Crofts
- Department of Plant and Microbial Biology, University of California at Berkeley Berkeley, CA, USA
| | - Yujie Men
- Department of Civil and Environmental Engineering, University of California at Berkeley Berkeley, CA, USA
| | - Lisa Alvarez-Cohen
- Department of Civil and Environmental Engineering, University of California at Berkeley Berkeley, CA, USA
| | - Michiko E Taga
- Department of Plant and Microbial Biology, University of California at Berkeley Berkeley, CA, USA
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Renpenning J, Keller S, Cretnik S, Shouakar-Stash O, Elsner M, Schubert T, Nijenhuis I. Combined C and Cl isotope effects indicate differences between corrinoids and enzyme (Sulfurospirillum multivorans PceA) in reductive dehalogenation of tetrachloroethene, but not trichloroethene. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2014; 48:11837-11845. [PMID: 25216120 DOI: 10.1021/es503306g] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
The role of the corrinoid cofactor in reductive dehalogenation catalysis by tetrachloroethene reductive dehalogenase (PceA) of Sulfurospirillum multivorans was investigated using isotope analysis of carbon and chlorine. Crude extracts containing PceA--harboring either a native norpseudo-B12 or the alternative nor-B12 cofactor--were applied for dehalogenation of tetrachloroethene (PCE) or trichloroethene (TCE), and compared to abiotic dehalogenation with the respective purified corrinoids (norpseudovitamin B12 and norvitamin B12), as well as several commercially available cobalamins and cobinamide. Dehalogenation of TCE resulted in a similar extent of C and Cl isotope fractionation, and in similar dual-element isotope slopes (εC/εCl) of 5.0-5.3 for PceA enzyme and 3.7-4.5 for the corrinoids. Both observations support an identical reaction mechanism. For PCE, in contrast, observed C and Cl isotope fractionation was smaller in enzymatic dehalogenation, and dual-element isotope slopes (2.2-2.8) were distinctly different compared to dehalogenation mediated by corrinoids (4.6-7.0). Remarkably, εC/εCl of PCE depended in addition on the corrinoid type: εC/εCl values of 4.6 and 5.0 for vitamin B12 and norvitamin B12 were significantly different compared to values of 6.9 and 7.0 for norpseudovitamin B12 and dicyanocobinamide. Our results therefore suggest mechanistic and/or kinetic differences in catalytic PCE dehalogenation by enzymes and different corrinoids, whereas such differences were not observed for TCE.
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Affiliation(s)
- Julian Renpenning
- Department for Isotope Biogeochemistry, Helmholtz-Centre for Environmental Research - UFZ , Permoserstrasse 15, D-04318 Leipzig, Germany
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Crofts TS, Seth EC, Hazra AB, Taga ME. Cobamide structure depends on both lower ligand availability and CobT substrate specificity. ACTA ACUST UNITED AC 2013; 20:1265-74. [PMID: 24055007 DOI: 10.1016/j.chembiol.2013.08.006] [Citation(s) in RCA: 58] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2013] [Revised: 07/01/2013] [Accepted: 08/05/2013] [Indexed: 11/16/2022]
Abstract
Cobamides are members of the vitamin B12 family of cofactors that function in a variety of metabolic processes and are synthesized only by prokaryotes. Cobamides produced by different organisms vary in the structure of the lower axial ligand. Here we explore the molecular factors that control specificity in the incorporation of lower ligand bases into cobamides. We find that the cobT gene product, which activates lower ligand bases for attachment, limits the range of lower ligand bases that can be incorporated by bacteria. Furthermore, we demonstrate that the substrate specificity of CobT can be predictably altered by changing two active site residues. These results demonstrate that sequence variations in cobT homologs contribute to cobamide structural diversity. This analysis could open new routes to engineering specific cobamide production and understanding cobamide-dependent processes.
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Affiliation(s)
- Terence S Crofts
- Department of Plant and Microbial Biology, University of California, Berkeley, Berkeley, CA 94720, USA
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