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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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Mok KC, Hallberg ZF, Procknow RR, Taga ME. Laboratory evolution of E. coli with a natural vitamin B 12 analog reveals roles for cobamide uptake and adenosylation in methionine synthase-dependent growth. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.01.04.574217. [PMID: 38260444 PMCID: PMC10802341 DOI: 10.1101/2024.01.04.574217] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/24/2024]
Abstract
The majority of bacteria use cobamides as cofactors for methionine synthesis or other diverse metabolic processes. Cobamides are a structurally diverse family of cofactors related to vitamin B12 (cobalamin), and most bacteria studied to date grow most robustly with particular cobamides. Because different environments contain varying abundances of distinct cobamides, bacteria are likely to encounter cobamides that do not function efficiently for their metabolism. Here, we performed a laboratory evolution of a cobamide-dependent strain of Escherichia coli with pseudocobalamin (pCbl), a cobamide that E. coli uses less effectively than cobalamin for MetH-dependent methionine synthesis, to identify genetic adaptations that lead to improved growth with less-preferred cobamides. After propagating and sequencing nine independent lines and validating the results by constructing targeted mutations, we found that increasing expression of the outer membrane cobamide transporter BtuB is beneficial during growth under cobamide-limiting conditions. Unexpectedly, we also found that overexpression of the cobamide adenosyltransferase BtuR confers a specific growth advantage in pCbl. Characterization of this phenotype revealed that BtuR and adenosylated cobamides contribute to optimal MetH-dependent growth. Together, these findings improve our understanding of how bacteria expand their cobamide-dependent metabolic potential.
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Affiliation(s)
- Kenny C. Mok
- Department of Plant & Microbial Biology, University of California, Berkeley, Berkeley, CA U.S.A
| | - Zachary F. Hallberg
- Department of Plant & Microbial Biology, University of California, Berkeley, Berkeley, CA U.S.A
| | - Rebecca R. Procknow
- Department of Plant & Microbial Biology, University of California, Berkeley, Berkeley, CA U.S.A
| | - Michiko E. Taga
- Department of Plant & Microbial Biology, University of California, Berkeley, Berkeley, CA U.S.A
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3
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Hallberg ZF, Seth EC, Thevasundaram K, Taga ME. Comparative Analysis of Corrinoid Profiles across Host-Associated and Environmental Samples. Biochemistry 2022; 61:2791-2796. [PMID: 36037062 DOI: 10.1021/acs.biochem.2c00367] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
Vitamin B12 (the cyanated form of cobalamin cofactors) is best known for its essential role in human health. In addition to its function in human metabolism, cobalamin also plays important roles in microbial metabolism and can impact microbial community function. Cobalamin is a member of the structurally diverse family of cofactors known as cobamides that are produced exclusively by certain prokaryotes. Cobamides are considered shared nutrients in microbial communities because the majority of bacteria that possess cobamide-dependent enzymes cannot synthesize cobamides de novo. Furthermore, different microbes have evolved metabolic specificity for particular cobamides, and therefore, the availability of cobamides in the environment is important for cobamide-dependent microbes. Determining the cobamides present in an environment of interest is essential for understanding microbial metabolic interactions. By examining the abundances of different cobamides in diverse environments, including 10 obtained in this study, we find that, contrary to its preeminence in human metabolism, cobalamin is relatively rare in many microbial habitats. Comparison of cobamide profiles of mammalian gastrointestinal samples and wood-feeding insects reveals that host-associated cobamide abundances vary and that fecal cobamide profiles differ from those of their host gastrointestinal tracts. Environmental cobamide profiles obtained from aquatic, soil, and contaminated groundwater samples reveal that the cobamide compositions of environmental samples are highly variable. As the only commercially available cobamide, cobalamin is routinely supplied during microbial culturing efforts. However, these findings suggest that cobamides specific to a given microbiome may yield greater insight into nutrient utilization and physiological processes that occur in these habitats.
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Affiliation(s)
- Zachary F Hallberg
- Department of Plant & Microbial Biology, University of California, Berkeley, Berkeley, California 94720, United States
| | - Erica C Seth
- Department of Plant & Microbial Biology, University of California, Berkeley, Berkeley, California 94720, United States
| | - Kersh Thevasundaram
- Department of Molecular & Cell Biology, University of California, Berkeley, Berkeley, California 94720, United States
| | - Michiko E Taga
- Department of Plant & Microbial Biology, University of California, Berkeley, Berkeley, California 94720, United States
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4
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Intraintestinal Analysis of the Functional Activity of Microbiomes and Its Application to the Common Marmoset Intestine. mSystems 2022; 7:e0052022. [PMID: 36005400 PMCID: PMC9601136 DOI: 10.1128/msystems.00520-22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
The intestinal microbiome is closely related to host health, and metatranscriptomic analysis can be used to assess the functional activity of microbiomes by quantifying microbial gene expression levels, helping elucidate the interactions between the microbiome and the environment. However, the functional changes in the microbiome along the host intestinal tract remain unknown, and previous analytical methods have limitations, such as potentially overlooking unknown genes due to dependence on existing databases. The objective of this study is to develop a computational pipeline combined with next-generation sequencing for spatial covariation analysis of the functional activity of microbiomes at multiple intestinal sites (biogeographic locations) within the same individual. This method reconstructs a reference metagenomic sequence across multiple intestinal sites and integrates the metagenome and metatranscriptome, allowing the gene expression levels of the microbiome, including unknown bacterial genes, to be compared among multiple sites. When this method was applied to metatranscriptomic analysis in the intestinal tract of common marmosets, a New World monkey, the reconstructed metagenome covered most of the expressed genes and revealed that the differences in microbial gene expression among the cecum, transverse colon, and feces were more dynamic and sensitive to environmental shifts than the abundances of the genes. In addition, metatranscriptomic profiling at three intestinal sites of the same individual enabled covariation analysis incorporating spatial relevance, accurately predicting the function of a total of 10,856 unknown genes. Our findings demonstrate that our proposed analytical method captures functional changes in microbiomes at the gene resolution level. IMPORTANCE We developed an analysis method that integrates metagenomes and metatranscriptomes from multiple intestinal sites to elucidate how microbial function varies along the intestinal tract. This method enables spatial covariation analysis of the functional activity of microbiomes and accurate identification of gene expression changes among intestinal sites, including changes in the expression of unknown bacterial genes. Moreover, we applied this method to the investigation of the common marmoset intestine, which is anatomically and pharmacologically similar to that of humans. Our findings indicate the expression pattern of the microbiome varies in response to changes in the internal environment along the intestinal tract, and this microbial change may affect the intestinal environment.
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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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Uptake of Phytoplankton-Derived Carbon and Cobalamins by Novel Acidobacteria Genera in Microcystis Blooms Inferred from Metagenomic and Metatranscriptomic Evidence. Appl Environ Microbiol 2022; 88:e0180321. [PMID: 35862730 PMCID: PMC9317899 DOI: 10.1128/aem.01803-21] [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: 01/07/2023] Open
Abstract
Interactions between bacteria and phytoplankton can influence primary production, community composition, and algal bloom development. However, these interactions are poorly described for many consortia, particularly for freshwater bloom-forming cyanobacteria. Here, we assessed the gene content and expression of two uncultivated Acidobacteria from Lake Erie Microcystis blooms. These organisms were targeted because they were previously identified as important catalase producers in Microcystis blooms, suggesting that they protect Microcystis from H2O2. Metatranscriptomics revealed that both Acidobacteria transcribed genes for uptake of organic compounds that are known cyanobacterial products and exudates, including lactate, glycolate, amino acids, peptides, and cobalamins. Expressed genes for amino acid metabolism and peptide transport and degradation suggest that use of amino acids and peptides by Acidobacteria may regenerate nitrogen for cyanobacteria and other organisms. The Acidobacteria genomes lacked genes for biosynthesis of cobalamins but expressed genes for its transport and remodeling. This indicates that the Acidobacteria obtained cobalamins externally, potentially from Microcystis, which has a complete gene repertoire for pseudocobalamin biosynthesis; expressed them in field samples; and produced pseudocobalamin in axenic culture. Both Acidobacteria were detected in Microcystis blooms worldwide. Together, the data support the hypotheses that uncultured and previously unidentified Acidobacteria taxa exchange metabolites with phytoplankton during harmful cyanobacterial blooms and influence nitrogen available to phytoplankton. Thus, novel Acidobacteria may play a role in cyanobacterial physiology and bloom development. IMPORTANCE Interactions between heterotrophic bacteria and phytoplankton influence competition and successions between phytoplankton taxa, thereby influencing ecosystem-wide processes such as carbon cycling and algal bloom development. The cyanobacterium Microcystis forms harmful blooms in freshwaters worldwide and grows in buoyant colonies that harbor other bacteria in their phycospheres. Bacteria in the phycosphere and in the surrounding community likely influence Microcystis physiology and ecology and thus the development of freshwater harmful cyanobacterial blooms. However, the impacts and mechanisms of interaction between bacteria and Microcystis are not fully understood. This study explores the mechanisms of interaction between Microcystis and uncultured members of its phycosphere in situ with population genome resolution to investigate the cooccurrence of Microcystis and freshwater Acidobacteria in blooms worldwide.
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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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Panwar P, Allen MA, Williams TJ, Haque S, Brazendale S, Hancock AM, Paez-Espino D, Cavicchioli R. Remarkably coherent population structure for a dominant Antarctic Chlorobium species. MICROBIOME 2021; 9:231. [PMID: 34823595 PMCID: PMC8620254 DOI: 10.1186/s40168-021-01173-z] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/06/2021] [Accepted: 10/09/2021] [Indexed: 05/22/2023]
Abstract
BACKGROUND In Antarctica, summer sunlight enables phototrophic microorganisms to drive primary production, thereby "feeding" ecosystems to enable their persistence through the long, dark winter months. In Ace Lake, a stratified marine-derived system in the Vestfold Hills of East Antarctica, a Chlorobium species of green sulphur bacteria (GSB) is the dominant phototroph, although its seasonal abundance changes more than 100-fold. Here, we analysed 413 Gb of Antarctic metagenome data including 59 Chlorobium metagenome-assembled genomes (MAGs) from Ace Lake and nearby stratified marine basins to determine how genome variation and population structure across a 7-year period impacted ecosystem function. RESULTS A single species, Candidatus Chlorobium antarcticum (most similar to Chlorobium phaeovibrioides DSM265) prevails in all three aquatic systems and harbours very little genomic variation (≥ 99% average nucleotide identity). A notable feature of variation that did exist related to the genomic capacity to biosynthesize cobalamin. The abundance of phylotypes with this capacity changed seasonally ~ 2-fold, consistent with the population balancing the value of a bolstered photosynthetic capacity in summer against an energetic cost in winter. The very high GSB concentration (> 108 cells ml-1 in Ace Lake) and seasonal cycle of cell lysis likely make Ca. Chlorobium antarcticum a major provider of cobalamin to the food web. Analysis of Ca. Chlorobium antarcticum viruses revealed the species to be infected by generalist (rather than specialist) viruses with a broad host range (e.g., infecting Gammaproteobacteria) that were present in diverse Antarctic lakes. The marked seasonal decrease in Ca. Chlorobium antarcticum abundance may restrict specialist viruses from establishing effective lifecycles, whereas generalist viruses may augment their proliferation using other hosts. CONCLUSION The factors shaping Antarctic microbial communities are gradually being defined. In addition to the cold, the annual variation in sunlight hours dictates which phototrophic species can grow and the extent to which they contribute to ecosystem processes. The Chlorobium population studied was inferred to provide cobalamin, in addition to carbon, nitrogen, hydrogen, and sulphur cycling, as critical ecosystem services. The specific Antarctic environmental factors and major ecosystem benefits afforded by this GSB likely explain why such a coherent population structure has developed in this Chlorobium species. Video abstract.
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Affiliation(s)
- Pratibha Panwar
- School of Biotechnology and Biomolecular Sciences, UNSW Sydney, Sydney, New South Wales, 2052, Australia
| | - Michelle A Allen
- School of Biotechnology and Biomolecular Sciences, UNSW Sydney, Sydney, New South Wales, 2052, Australia
| | - Timothy J Williams
- School of Biotechnology and Biomolecular Sciences, UNSW Sydney, Sydney, New South Wales, 2052, Australia
| | - Sabrina Haque
- School of Biotechnology and Biomolecular Sciences, UNSW Sydney, Sydney, New South Wales, 2052, Australia
- Present address: Department of Molecular Sciences, Macquarie University, Sydney, New South Wales, 2109, Australia
| | - Sarah Brazendale
- School of Biotechnology and Biomolecular Sciences, UNSW Sydney, Sydney, New South Wales, 2052, Australia
- , Present address: Pegarah, Australia
| | - Alyce M Hancock
- School of Biotechnology and Biomolecular Sciences, UNSW Sydney, Sydney, New South Wales, 2052, Australia
- Present address: Institute for Marine and Antarctic Studies, University of Tasmania, 20 Castray Esplanade, Battery Point, Tasmania, Australia
| | - David Paez-Espino
- Department of Energy Joint Genome Institute, Berkeley, CA, USA
- Present address: Mammoth Biosciences, Inc., 1000 Marina Blvd. Suite 600, Brisbane, CA, USA
| | - Ricardo Cavicchioli
- School of Biotechnology and Biomolecular Sciences, UNSW Sydney, Sydney, New South Wales, 2052, Australia.
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9
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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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Kruse S, Türkowsky D, Birkigt J, Matturro B, Franke S, Jehmlich N, von Bergen M, Westermann M, Rossetti S, Nijenhuis I, Adrian L, Diekert G, Goris T. Interspecies metabolite transfer and aggregate formation in a co-culture of Dehalococcoides and Sulfurospirillum dehalogenating tetrachloroethene to ethene. THE ISME JOURNAL 2021; 15:1794-1809. [PMID: 33479489 PMCID: PMC8163811 DOI: 10.1038/s41396-020-00887-6] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/26/2020] [Revised: 12/04/2020] [Accepted: 12/16/2020] [Indexed: 01/30/2023]
Abstract
Microbial communities involving dehalogenating bacteria assist in bioremediation of areas contaminated with halocarbons. To understand molecular interactions between dehalogenating bacteria, we co-cultured Sulfurospirillum multivorans, dechlorinating tetrachloroethene (PCE) to cis-1,2-dichloroethene (cDCE), and Dehalococcoides mccartyi strains BTF08 or 195, dehalogenating PCE to ethene. The co-cultures were cultivated with lactate as electron donor. In co-cultures, the bacterial cells formed aggregates and D. mccartyi established an unusual, barrel-like morphology. An extracellular matrix surrounding bacterial cells in the aggregates enhanced cell-to-cell contact. PCE was dehalogenated to ethene at least three times faster in the co-culture. The dehalogenation was carried out via PceA of S. multivorans, and PteA (a recently described PCE dehalogenase) and VcrA of D. mccartyi BTF08, as supported by protein abundance. The co-culture was not dependent on exogenous hydrogen and acetate, suggesting a syntrophic relationship in which the obligate hydrogen consumer D. mccartyi consumes hydrogen and acetate produced by S. multivorans. The cobamide cofactor of the reductive dehalogenase-mandatory for D. mccartyi-was also produced by S. multivorans. D. mccartyi strain 195 dechlorinated cDCE in the presence of norpseudo-B12 produced by S. multivorans, but D. mccartyi strain BTF08 depended on an exogenous lower cobamide ligand. This observation is important for bioremediation, since cofactor supply in the environment might be a limiting factor for PCE dehalogenation to ethene, described for D. mccartyi exclusively. The findings from this co-culture give new insights into aggregate formation and the physiology of D. mccartyi within a bacterial community.
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Affiliation(s)
- Stefan Kruse
- grid.9613.d0000 0001 1939 2794Department of Applied and Ecological Microbiology, Institute of Microbiology, Friedrich Schiller University, Jena, Germany
| | - Dominique Türkowsky
- grid.7492.80000 0004 0492 3830Department Molecular Systems Biology, Helmholtz Centre for Environmental Research – UFZ, Leipzig, Germany
| | - Jan Birkigt
- grid.7492.80000 0004 0492 3830Department of Isotope Biogeochemistry, Helmholtz Centre for Environmental Research – UFZ, Leipzig, Germany
| | - Bruna Matturro
- grid.435629.f0000 0004 1755 3971Water Research Institute, IRSA-CNR, Monterotondo, Rome, Italy
| | - Steffi Franke
- grid.7492.80000 0004 0492 3830Department of Isotope Biogeochemistry, Helmholtz Centre for Environmental Research – UFZ, Leipzig, Germany ,Present Address: Eurofins Institute Dr. Appelt Leipzig, Leipzig, Germany
| | - Nico Jehmlich
- grid.7492.80000 0004 0492 3830Department Molecular Systems Biology, Helmholtz Centre for Environmental Research – UFZ, Leipzig, Germany
| | - Martin von Bergen
- grid.7492.80000 0004 0492 3830Department Molecular Systems Biology, Helmholtz Centre for Environmental Research – UFZ, Leipzig, Germany ,grid.9647.c0000 0004 7669 9786Institute of Biochemistry, Faculty of Life Sciences, University of Leipzig, Leipzig, Germany
| | - Martin Westermann
- grid.275559.90000 0000 8517 6224Center for Electron Microscopy of the University Hospital Jena, Jena, Germany
| | - Simona Rossetti
- grid.435629.f0000 0004 1755 3971Water Research Institute, IRSA-CNR, Monterotondo, Rome, Italy
| | - Ivonne Nijenhuis
- grid.7492.80000 0004 0492 3830Department of Isotope Biogeochemistry, Helmholtz Centre for Environmental Research – UFZ, Leipzig, Germany
| | - Lorenz Adrian
- grid.6734.60000 0001 2292 8254Chair of Geobiotechnology, Technische Universität Berlin, Berlin, Germany ,grid.7492.80000 0004 0492 3830Department of Environmental Biotechnology, Helmholtz Centre for Environmental Research - UFZ, Leipzig, Germany
| | - Gabriele Diekert
- grid.9613.d0000 0001 1939 2794Department of Applied and Ecological Microbiology, Institute of Microbiology, Friedrich Schiller University, Jena, Germany
| | - Tobias Goris
- grid.9613.d0000 0001 1939 2794Department of Applied and Ecological Microbiology, Institute of Microbiology, Friedrich Schiller University, Jena, Germany ,grid.418213.d0000 0004 0390 0098Present Address: German Institute of Human Nutrition, Department Molecular Toxicology, Research Group Intestinal Microbiology, Potsdam-Rehbrücke, Nuthetal, Germany
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11
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Identification of a Novel Cobamide Remodeling Enzyme in the Beneficial Human Gut Bacterium Akkermansia muciniphila. mBio 2020; 11:mBio.02507-20. [PMID: 33293380 PMCID: PMC7733943 DOI: 10.1128/mbio.02507-20] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
Cobamides, comprising the vitamin B12 family of cobalt-containing cofactors, are required for metabolism in all domains of life, including most bacteria. Cobamides have structural variability in the lower ligand, and selectivity for particular cobamides has been observed in most organisms studied to date. The beneficial human gut bacterium Akkermansia muciniphila provides metabolites to other members of the gut microbiota by breaking down host mucin, but most of its other metabolic functions have not been investigated. A. muciniphila strain MucT is known to use cobamides, the vitamin B12 family of cofactors with structural diversity in the lower ligand. However, A. muciniphila MucT is unable to synthesize cobamides de novo, and the specific forms that can be used by A. muciniphila have not been examined. We found that the levels of growth of A. muciniphila MucT were nearly identical with each of seven cobamides tested, in contrast to nearly all bacteria that had been studied previously. Unexpectedly, this promiscuity is due to cobamide remodeling—the removal and replacement of the lower ligand—despite the absence of the canonical remodeling enzyme CbiZ in A. muciniphila. We identified a novel enzyme, CbiR, that is capable of initiating the remodeling process by hydrolyzing the phosphoribosyl bond in the nucleotide loop of cobamides. CbiR does not share similarity with other cobamide remodeling enzymes or B12-binding domains and is instead a member of the apurinic/apyrimidinic (AP) endonuclease 2 enzyme superfamily. We speculate that CbiR enables bacteria to repurpose cobamides that they cannot otherwise use in order to grow under cobamide-requiring conditions; this function was confirmed by heterologous expression of cbiR in Escherichia coli. Homologs of CbiR are found in over 200 microbial taxa across 22 phyla, suggesting that many bacteria may use CbiR to gain access to the diverse cobamides present in their environment.
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Baum C, Menezes RC, Svatoš A, Schubert T. Cobamide remodeling in the freshwater microalga Chlamydomonas reinhardtii. FEMS Microbiol Lett 2020; 367:5932200. [DOI: 10.1093/femsle/fnaa171] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2020] [Accepted: 10/16/2020] [Indexed: 11/13/2022] Open
Abstract
ABSTRACTMicroalgae are not able to produce cobamides (Cbas, B12 vitamers) de novo. Hence, the production of catalytically active Cba-containing methionine synthase (MetH), which is present in selected representatives, is dependent on the availability of exogenous B12 vitamers. Preferences in the utilization of exogenous Cbas equipped with either adenine or 5,6-dimethylbenzimidazole as lower base have been reported for some microalgae. Here, we investigated the utilization of norcobamides (NorCbas) for growth by the Cba-dependent Chlamydomonas reinhardtii mutant strain (ΔmetE). The growth yields in the presence of NorCbas were lower in comparison to those achieved with Cbas. NorCbas lack a methyl group in the linker moiety of the nucleotide loop. C. reinhardtii was also tested for the remodeling of NorCbas (e.g. adeninyl-norcobamide) in the presence of different benzimidazoles. Extraction of the NorCbas from C. reinhardtii, their purification, and identification confirmed the exchange of the lower base of the vitamers. However, the linker moiety of the NorCbas nucleotide loop was not exchanged. This observation strongly indicates the presence of an alternative mode of Cba deconstruction in C. reinhardtii that differs from the amidohydrolase (CbiZ)-dependent pathway described in Cba-remodeling bacteria and archaea.
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Affiliation(s)
- Christoph Baum
- Research Group Anaerobic Microbiology, Institute of Microbiology, Friedrich Schiller University, Philosophenweg 12, D-07743 Jena, Germany
| | - Riya C Menezes
- Research Group Mass Spectrometry, Max Planck Institute for Chemical Ecology, Hans-Knöll-Straße 8, D-07745 Jena, Germany
| | - Aleš Svatoš
- Research Group Mass Spectrometry, Max Planck Institute for Chemical Ecology, Hans-Knöll-Straße 8, D-07745 Jena, Germany
| | - Torsten Schubert
- Research Group Anaerobic Microbiology, Institute of Microbiology, Friedrich Schiller University, Philosophenweg 12, D-07743 Jena, Germany
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González-Montaña JR, Escalera-Valente F, Alonso AJ, Lomillos JM, Robles R, Alonso ME. Relationship between Vitamin B12 and Cobalt Metabolism in Domestic Ruminant: An Update. Animals (Basel) 2020; 10:E1855. [PMID: 33053716 PMCID: PMC7601760 DOI: 10.3390/ani10101855] [Citation(s) in RCA: 42] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2020] [Revised: 09/25/2020] [Accepted: 10/01/2020] [Indexed: 12/12/2022] Open
Abstract
Cobalt, as a trace element, is essential for rumen microorganisms for the formation of vitamin B12. In the metabolism of mammals, vitamin B12 is an essential part of two enzymatic systems involved in multiple metabolic reactions, such as in the metabolism of carbohydrates, lipids, some amino acids and DNA. Adenosylcobalamin and methylcobalamin are coenzymes of methylmalonyl coenzyme A (CoA) mutase and methionine synthetase and are essential for obtaining energy through ruminal metabolism. Signs of cobalt deficiency range from hyporexia, reduced growth and weight loss to liver steatosis, anemia, impaired immune function, impaired reproductive function and even death. Cobalt status in ruminant animals can be assessed by direct measurement of blood or tissue concentrations of cobalt or vitamin B12, as well as the level of methylmalonic acid, homocysteine or transcobalamin in blood; methylmalonic acid in urine; some variables hematological; food consumption or growth of animals. In general, it is assumed that the requirement for cobalt (Co) is expressed around 0.11 ppm (mg/kg) in the dry matter (DM) diet; current recommendations seem to advise increasing Co supplementation and placing it around 0.20 mg Co/kg DM. Although there is no unanimous criterion about milk production, fattening or reproductive rates in response to increased supplementation with Co, in some investigations, when the total Co of the diet was approximately 1 to 1.3 ppm (mg/kg), maximum responses were observed in the milk production.
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Affiliation(s)
- Jose-Ramiro González-Montaña
- Medicine, Surgery and Anatomy Veterinary Department, Veterinary Faculty, University of León, 24071 León, Spain; (A.J.A.); (R.R.)
| | - Francisco Escalera-Valente
- Academic Unit of Veterinary Medicine and Zootechnics, Autonomous University of Nayarit, Tepic 69130, Nayarit, Mexico;
| | - Angel J. Alonso
- Medicine, Surgery and Anatomy Veterinary Department, Veterinary Faculty, University of León, 24071 León, Spain; (A.J.A.); (R.R.)
| | - Juan M. Lomillos
- Production and Health Animal, Public Health Veterinary and Science and Technology of Food Department, Veterinary Faculty, Cardenal Herrera-CEU University, 46115 Valencia, Spain;
| | - Roberto Robles
- Medicine, Surgery and Anatomy Veterinary Department, Veterinary Faculty, University of León, 24071 León, Spain; (A.J.A.); (R.R.)
| | - Marta E. Alonso
- Animal Production Department, Veterinary Faculty, Veterinary Faculty, University of León, 24071 León, Spain;
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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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Abstract
In this paper, we examined the microbiome of the bovine rumen, feces, and milk and attempted to understand how the bacterial communities at each site affected the production and movement of vitamin B12 around the animal’s body. It was determined that the composition of the bovine rumen microbiome correlates well with vitamin B12 concentration, indicating that the rumen microbiota may be a good target for manipulation to improve production of this important vitamin. Vitamin B12 is synthesized by prokaryotes in the rumens of dairy cows—and this has implications in human nutrition since humans rely on consumption of dairy products for vitamin B12 acquisition. However, the concentration of vitamin B12 in milk is highly variable, and there is interest in determining what causes vitamin B12 variability. We collected 92 temporally linked rumen, fecal, blood, and milk sample sets from Holstein cows at various stages of lactation fitted with rumen cannula and attempted to define which bacterial genera correlated well with vitamin B12 abundance. The level of vitamin B12 present in each sample was measured, and the bacterial population of each rumen, fecal, and milk sample (n = 263) was analyzed by 16S rRNA-targeted amplicon sequencing of the V4 region. The bacterial populations present in the rumen, small intestine, and milk were highly dissimilar. Combined diet and lactation status had significant effects on the composition of the microbiota in the rumen and in the feces. A high ruminal concentration of vitamin B12 was correlated with the increased abundance of Prevotella, while a low ruminal concentration of vitamin B12 was correlated with increased abundance of Bacteroidetes, Ruminiclostridium, and Butyrivibrio. The ultimate concentration of vitamin B12 is controlled by the complex interaction of several factors, including the composition of the microbiota. Bacterial consumption of vitamin B12 in the rumen may be more important in determining overall levels than bacterial production. IMPORTANCE In this paper, we examined the microbiome of the bovine rumen, feces, and milk and attempted to understand how the bacterial communities at each site affected the production and movement of vitamin B12 around the animal’s body. It was determined that the composition of the bovine rumen microbiome correlates well with vitamin B12 concentration, indicating that the rumen microbiota may be a good target for manipulation to improve production of this important vitamin.
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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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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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Gude S, Taga ME. Multi-faceted approaches to discovering and predicting microbial nutritional interactions. Curr Opin Biotechnol 2019; 62:58-64. [PMID: 31597114 DOI: 10.1016/j.copbio.2019.08.005] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2019] [Revised: 08/08/2019] [Accepted: 08/20/2019] [Indexed: 01/07/2023]
Abstract
Nearly all microbes rely on other species in their environment to provide nutrients they are unable to produce. Nutritional interactions include not only the exchange of carbon and nitrogen compounds, but also amino acids and cofactors. Interactions involving cross-feeding of cobamides, the vitamin B12 family of cofactors, have been developed as a model for nutritional interactions across species and environments. In addition to experimental studies, new developments in culture-independent methodologies such as genomics and modeling now enable the prediction of nutritional interactions in a broad range of organisms including those that cannot be cultured in the laboratory. New insights into the mechanisms and evolution of microbial nutritional interactions are beginning to emerge by combining experimental, genomic, and modeling approaches.
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Affiliation(s)
- Sebastian Gude
- Department of Plant & Microbial Biology, University of California, Berkeley, CA USA
| | - Michiko E Taga
- Department of Plant & Microbial Biology, University of California, Berkeley, CA USA.
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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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20
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Tavares NK, VanDrisse CM, Escalante-Semerena JC. Rhodobacterales use a unique L-threonine kinase for the assembly of the nucleotide loop of coenzyme B 12. Mol Microbiol 2018; 110:239-261. [PMID: 30098062 DOI: 10.1111/mmi.14100] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
Several of the enzymes involved in the conversion of adenosylcobyric acid (AdoCby) to adenosylcobamide (AdoCba) are yet to be identified and characterized in some cobamide (Cba)-producing prokaryotes. Using a bioinformatics approach, we identified the bluE gene (locus tag RSP_0788) of Rhodobacter sphaeroides 2.4.1 as a putative functional homolog of the L-threonine kinase enzyme (PduX, EC 2.7.1.177) of S. enterica. In AdoCba, (R)-1-aminopropan-2-ol O-phosphate (AP-P) links the nucleotide loop to the corrin ring; most known AdoCba producers derive AP-P from L-Thr-O-3-phosphate (L-Thr-P). Here, we show that RsBluE has L-Thr-independent ATPase activity in vivo and in vitro. We used 31 P-NMR spectroscopy to show that RsBluE generates L-Thr-P at the expense of ATP and is unable to use L-Ser as a substrate. BluE from R. sphaeroides or Rhodobacter capsulatus restored AdoCba biosynthesis in S. enterica ΕpduX and R. sphaeroides ΕbluE mutant strains. R. sphaeroides ΕbluE strains exhibited a decreased pigment phenotype that was restored by complementation with BluE. Finally, phylogenetic analyses revealed that bluE was restricted to the genomes of a few Rhodobacterales that appear to have a preference for a specific form of Cba, namely Coᴽ-(ᴽ-5,6-dimethylbenzimidazolyl-Coᵦ-adenosylcobamide (a.k.a. adenosylcobalamin, AdoCbl; coenzyme B12 , CoB12 ).
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Frank SA. Receptor uptake arrays for vitamin B 12, siderophores, and glycans shape bacterial communities. Ecol Evol 2017; 7:10175-10195. [PMID: 29238546 PMCID: PMC5723603 DOI: 10.1002/ece3.3544] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2017] [Revised: 08/20/2017] [Accepted: 09/28/2017] [Indexed: 01/15/2023] Open
Abstract
Molecular variants of vitamin B12, siderophores, and glycans occur. To take up variant forms, bacteria may express an array of receptors. The gut microbe Bacteroides thetaiotaomicron has three different receptors to take up variants of vitamin B12 and 88 receptors to take up various glycans. The design of receptor arrays reflects key processes that shape cellular evolution. Competition may focus each species on a subset of the available nutrient diversity. Some gut bacteria can take up only a narrow range of carbohydrates, whereas species such as B. thetaiotaomicron can digest many different complex glycans. Comparison of different nutrients, habitats, and genomes provides opportunity to test hypotheses about the breadth of receptor arrays. Another important process concerns fluctuations in nutrient availability. Such fluctuations enhance the value of cellular sensors, which gain information about environmental availability and adjust receptor deployment. Bacteria often adjust receptor expression in response to fluctuations of particular carbohydrate food sources. Some species may adjust expression of uptake receptors for specific siderophores. How do cells use sensor information to control the response to fluctuations? This question about regulatory wiring relates to problems that arise in control theory and artificial intelligence. Control theory clarifies how to analyze environmental fluctuations in relation to the design of sensors and response systems. Recent advances in deep learning studies of artificial intelligence focus on the architecture of regulatory wiring and the ways in which complex control networks represent and classify environmental states. I emphasize the similar design problems that arise in cellular evolution, control theory, and artificial intelligence. I connect those broad conceptual aspects to many testable hypotheses for bacterial uptake of vitamin B12, siderophores, and glycans.
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Affiliation(s)
- Steven A. Frank
- Department of Ecology and Evolutionary BiologyUniversity of CaliforniaIrvineCAUSA
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23
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Deptula P, Chamlagain B, Edelmann M, Sangsuwan P, Nyman TA, Savijoki K, Piironen V, Varmanen P. Food-Like Growth Conditions Support Production of Active Vitamin B12 by Propionibacterium freudenreichii 2067 without DMBI, the Lower Ligand Base, or Cobalt Supplementation. Front Microbiol 2017; 8:368. [PMID: 28337185 PMCID: PMC5340759 DOI: 10.3389/fmicb.2017.00368] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2017] [Accepted: 02/22/2017] [Indexed: 01/01/2023] Open
Abstract
Propionibacterium freudenreichii is a traditional dairy bacterium and a producer of short chain fatty acids (propionic and acetic acids) as well as vitamin B12. In food applications, it is a promising organism for in situ fortification with B12 vitamin since it is generally recognized as safe (GRAS) and it is able to synthesize biologically active form of the vitamin. In the present study, vitamin B12 and pseudovitamin biosynthesis by P. freudenreichii was monitored by UHPLC as a function of growth in food-like conditions using a medium mimicking cheese environment, without cobalt or 5,6-dimethylbenzimidazole (DMBI) supplementation. Parallel growth experiments were performed in industrial-type medium known to support the biosynthesis of vitamin B12. The production of other key metabolites in the two media were determined by HPLC, while the global protein production was compared by gel-based proteomics to assess the effect of growth conditions on the physiological status of the strain and on the synthesis of different forms of vitamin. The results revealed distinct protein and metabolite production, which reflected the growth conditions and the potential of P. freudenreichii for synthesizing nutritionally relevant amounts of active vitamin B12 regardless of the metabolic state of the cells.
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Affiliation(s)
- Paulina Deptula
- Department of Food and Environmental Sciences, University of Helsinki Helsinki, Finland
| | - Bhawani Chamlagain
- Department of Food and Environmental Sciences, University of Helsinki Helsinki, Finland
| | - Minnamari Edelmann
- Department of Food and Environmental Sciences, University of Helsinki Helsinki, Finland
| | - Panchanit Sangsuwan
- Department of Food and Environmental Sciences, University of Helsinki Helsinki, Finland
| | - Tuula A Nyman
- Proteomics Unit, Institute of Biotechnology, University of Helsinki Helsinki, Finland
| | - Kirsi Savijoki
- Department of Food and Environmental Sciences, University of Helsinki Helsinki, Finland
| | - Vieno Piironen
- Department of Food and Environmental Sciences, University of Helsinki Helsinki, Finland
| | - Pekka Varmanen
- Department of Food and Environmental Sciences, University of Helsinki Helsinki, Finland
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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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Helliwell KE, Lawrence AD, Holzer A, Kudahl UJ, Sasso S, Kräutler B, Scanlan DJ, Warren MJ, Smith AG. Cyanobacteria and Eukaryotic Algae Use Different Chemical Variants of Vitamin B12. Curr Biol 2016; 26:999-1008. [PMID: 27040778 PMCID: PMC4850488 DOI: 10.1016/j.cub.2016.02.041] [Citation(s) in RCA: 132] [Impact Index Per Article: 16.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2016] [Revised: 02/15/2016] [Accepted: 02/17/2016] [Indexed: 01/04/2023]
Abstract
Eukaryotic microalgae and prokaryotic cyanobacteria are the major components of the phytoplankton. Determining factors that govern growth of these primary producers, and how they interact, is therefore essential to understanding aquatic ecosystem productivity. Over half of microalgal species representing marine and freshwater habitats require for growth the corrinoid cofactor B12, which is synthesized de novo only by certain prokaryotes, including the majority of cyanobacteria. There are several chemical variants of B12, which are not necessarily functionally interchangeable. Cobalamin, the form bioavailable to humans, has as its lower axial ligand 5,6-dimethylbenzimidazole (DMB). Here, we show that the abundant marine cyanobacterium Synechococcus synthesizes only pseudocobalamin, in which the lower axial ligand is adenine. Moreover, bioinformatic searches of over 100 sequenced cyanobacterial genomes for B12 biosynthesis genes, including those involved in nucleotide loop assembly, suggest this is the form synthesized by cyanobacteria more broadly. We further demonstrate that pseudocobalamin is several orders of magnitude less bioavailable than cobalamin to several B12-dependent microalgae representing diverse lineages. This indicates that the two major phytoplankton groups use a different B12 currency. However, in an intriguing twist, some microalgal species can use pseudocobalamin if DMB is provided, suggesting that they are able to remodel the cofactor, whereas Synechococcus cannot. This species-specific attribute implicates algal remodelers as novel and keystone players of the B12 cycle, transforming our perception of the dynamics and complexity of the flux of this nutrient in aquatic ecosystems. Dominant marine cyanobacteria synthesize only pseudocobalamin Pseudocobalamin is orders of magnitude less bioavailable to eukaryotic algae Certain algae can remodel pseudocobalamin to a bioavailable form This implies a complex B12 cycle between microbes in the photic zone
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Affiliation(s)
| | | | - Andre Holzer
- Department of Plant Sciences, University of Cambridge, Cambridge CB2 3EA, UK; Institute of Pharmacy and Molecular Biotechnology, Ruprecht-Karls University Heidelberg, Im Neuenheimer Feld 364, 69120 Heidelberg, Germany
| | - Ulrich Johan Kudahl
- Department of Plant Sciences, University of Cambridge, Cambridge CB2 3EA, UK
| | - Severin Sasso
- Department of Plant Sciences, University of Cambridge, Cambridge CB2 3EA, UK
| | - Bernhard Kräutler
- Institute of Organic Chemistry and Centre of Molecular Biosciences, University of Innsbruck, Innrain 80/82, 6020 Innsbruck, Austria
| | | | | | - Alison Gail Smith
- Department of Plant Sciences, University of Cambridge, Cambridge CB2 3EA, UK.
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Zelder F. Recent trends in the development of vitamin B12 derivatives for medicinal applications. Chem Commun (Camb) 2015; 51:14004-17. [PMID: 26287029 DOI: 10.1039/c5cc04843e] [Citation(s) in RCA: 68] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
This Feature Article highlights recent developments in the field of vitamin B12 derivatives for medicinal applications. The following topics are emphasized: (1) the development of aquacorrinoids for cyanide detection and detoxification, (2) the use of vitamin B12 conjugates and (3) antivitamins B12 for therapy and diagnosis, and (4) the design of corrinoids as activators of soluble guanylyl cyclase (sGC).
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Affiliation(s)
- Felix Zelder
- Department of Chemistry, University of Zürich, Winterthurerstr. 190, CH-8057 Zürich, Switzerland.
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Abstract
The microbial mechanisms and key metabolites that shape the composition of the human gut microbiota are largely unknown, impeding efforts to manipulate dysbiotic microbial communities toward stability and health. Vitamins, which by definition are not synthesized in sufficient quantities by the host and can mediate fundamental biological processes in microbes, represent an attractive target for reshaping microbial communities. Here, we discuss how vitamin B12 (cobalamin) impacts diverse host-microbe symbioses. Although cobalamin is synthesized by some human gut microbes, it is a precious resource in the gut and is likely not provisioned to the host in significant quantities. However, this vitamin may make an unrecognized contribution in shaping the structure and function of human gut microbial communities.
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Affiliation(s)
- Patrick H Degnan
- Department of Microbiology, University of Illinois at Urbana-Champaign, Urbana, IL 61801, USA
| | - Michiko E Taga
- Department of Plant & Microbial Biology, University of California, Berkeley, Berkeley, CA 94720, USA
| | - Andrew L Goodman
- Department of Microbial Pathogenesis and Microbial Sciences Institute, Yale University, New Haven, CT 06516, USA.
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Seth EC, Taga ME. Nutrient cross-feeding in the microbial world. Front Microbiol 2014; 5:350. [PMID: 25071756 PMCID: PMC4086397 DOI: 10.3389/fmicb.2014.00350] [Citation(s) in RCA: 183] [Impact Index Per Article: 18.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2014] [Accepted: 06/23/2014] [Indexed: 12/25/2022] Open
Abstract
The stability and function of a microbial community depends on nutritional interactions among community members such as the cross-feeding of essential small molecules synthesized by a subset of the population. In this review, we describe examples of microbe–microbe and microbe–host cofactor cross-feeding, a type of interaction that influences the forms of metabolism carried out within a community. Cofactor cross-feeding can contribute to both the health and nutrition of a host organism, the virulence and persistence of pathogens, and the composition and function of environmental communities. By examining the impact of shared cofactors on microbes from pure culture to natural communities, we stand to gain a better understanding of the interactions that link microbes together, which may ultimately be a key to developing strategies for manipulating microbial communities with human health, agricultural, and environmental implications.
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Affiliation(s)
- Erica C Seth
- Department of Plant and Microbial Biology, University of California, Berkeley, Berkeley, CA USA
| | - Michiko E Taga
- Department of Plant and Microbial Biology, University of California, Berkeley, Berkeley, CA USA
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Men Y, Seth EC, Yi S, Crofts TS, Allen RH, Taga ME, Alvarez-Cohen L. Identification of specific corrinoids reveals corrinoid modification in dechlorinating microbial communities. Environ Microbiol 2014; 17:4873-84. [PMID: 24803319 DOI: 10.1111/1462-2920.12500] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2013] [Revised: 04/16/2014] [Accepted: 04/30/2014] [Indexed: 11/27/2022]
Abstract
Cobalamin and other corrinoids are essential cofactors for many organisms. The majority of microbes with corrinoid-dependent enzymes do not produce corrinoids de novo, and instead must acquire corrinoids produced by other organisms in their environment. However, the profile of corrinoids produced in corrinoid-dependent microbial communities, as well as the exchange and modification of corrinoids among community members have not been well studied. In this study, we applied a newly developed liquid chromatography tandem mass spectrometry-based corrinoid detection method to examine relationships among corrinoids, their lower ligand bases and specific microbial groups in microbial communities containing Dehalococcoides mccartyi that has an obligate requirement for benzimidazole-containing corrinoids for trichloroethene respiration. We found that p-cresolylcobamide ([p-Cre]Cba) and cobalamin were the most abundant corrinoids in the communities. It suggests that members of the family Veillonellaceae are associated with the production of [p-Cre]Cba. The decrease of supernatant-associated [p-Cre]Cba and the increase of biomass-associated cobalamin were correlated with the growth of D. mccartyi by dechlorination. This supports the hypothesis that D. mccartyi is capable of fulfilling its corrinoid requirements in a community through corrinoid remodelling, in this case, by importing extracellular [p-Cre]Cba and 5,6-dimethylbenzimidazole (DMB) (the lower ligand of cobalamin), to produce cobalamin as a cofactor for dechlorination. This study also highlights the role of DMB, the lower ligand produced in all of the studied communities, in corrinoid remodelling. These findings provide novel insights on roles played by different phylogenetic groups in corrinoid production and corrinoid exchange within microbial communities. This study may also have implications for optimizing chlorinated solvent bioremediation.
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Affiliation(s)
- Yujie Men
- Department of Civil and Environmental Engineering, University of California, Berkeley, CA, 94720, USA
| | - Erica C Seth
- Department of Plant and Microbial Biology, University of California, Berkeley, CA, 94720, USA
| | - Shan Yi
- Department of Civil and Environmental Engineering, University of California, Berkeley, CA, 94720, USA
| | - Terence S Crofts
- Department of Plant and Microbial Biology, University of California, Berkeley, CA, 94720, USA
| | - Robert H Allen
- Division of Hematology, Department of Medicine, University of Colorado Anschutz Medical Campus, Aurora, CO, 80045, USA
| | - Michiko E Taga
- Department of Plant and Microbial Biology, University of California, Berkeley, CA, 94720, USA
| | - Lisa Alvarez-Cohen
- Department of Civil and Environmental Engineering, University of California, Berkeley, CA, 94720, USA.,Earth Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA, 94720, USA
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Degnan PH, Barry NA, Mok KC, Taga ME, Goodman AL. Human gut microbes use multiple transporters to distinguish vitamin B₁₂ analogs and compete in the gut. Cell Host Microbe 2014; 15:47-57. [PMID: 24439897 PMCID: PMC3923405 DOI: 10.1016/j.chom.2013.12.007] [Citation(s) in RCA: 182] [Impact Index Per Article: 18.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2013] [Revised: 11/13/2013] [Accepted: 12/18/2013] [Indexed: 12/20/2022]
Abstract
Genomic and metagenomic sequencing efforts, including human microbiome projects, reveal that microbes often encode multiple systems that appear to accomplish the same task. Whether these predictions reflect actual functional redundancies is unclear. We report that the prominent human gut symbiont Bacteroides thetaiotaomicron employs three functional, homologous vitamin B₁₂ transporters that in at least two cases confer a competitive advantage in the presence of distinct B₁₂ analogs (corrinoids). In the mammalian gut, microbial fitness can be determined by the presence or absence of a single transporter. The total number of distinct corrinoid transporter families in the human gut microbiome likely exceeds those observed in B. thetaiotaomicron by an order of magnitude. These results demonstrate that human gut microbes use elaborate mechanisms to capture and differentiate corrinoids in vivo and that apparent redundancies observed in these genomes can instead reflect hidden specificities that determine whether a microbe will colonize its host.
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Affiliation(s)
- Patrick H Degnan
- Department of Microbial Pathogenesis and Microbial Diversity Institute, Yale University, New Haven, CT 06536, USA
| | - Natasha A Barry
- Department of Microbial Pathogenesis and Microbial Diversity Institute, Yale University, New Haven, CT 06536, USA
| | - Kenny C Mok
- Department of Plant and Microbial Biology, University of California, Berkeley, Berkeley, CA 94720, USA
| | - Michiko E Taga
- Department of Plant and Microbial Biology, University of California, Berkeley, Berkeley, CA 94720, USA
| | - Andrew L Goodman
- Department of Microbial Pathogenesis and Microbial Diversity Institute, Yale University, New Haven, CT 06536, USA.
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Dissecting cobamide diversity through structural and functional analyses of the base-activating CobT enzyme of Salmonella enterica. Biochim Biophys Acta Gen Subj 2013; 1840:464-75. [PMID: 24121107 DOI: 10.1016/j.bbagen.2013.09.038] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2013] [Revised: 08/20/2013] [Accepted: 09/30/2013] [Indexed: 11/20/2022]
Abstract
BACKGROUND Cobamide diversity arises from the nature of the nucleotide base. Nicotinate mononucleotide (NaMN):base phosphoribosyltransferases (CobT) synthesize α-linked riboside monophosphates from diverse nucleotide base substrates (e.g., benzimidazoles, purines, phenolics) that are incorporated into cobamides. METHODS Structural investigations of two members of the CobT family of enzymes in complex with various substrate bases as well as in vivo and vitro activity analyses of enzyme variants were performed to elucidate the roles of key amino acid residues important for substrate recognition. RESULTS Results of in vitro and in vivo studies of active-site variants of the Salmonella enterica CobT (SeCobT) enzyme suggest that a catalytic base may not be required for catalysis. This idea is supported by the analyses of crystal structures that show that two glutamate residues function primarily to maintain an active conformation of the enzyme. In light of these findings, we propose that proper positioning of the substrates in the active site triggers the attack at the C1 ribose of NaMN. CONCLUSION Whether or not a catalytic base is needed for function is discussed within the framework of the in vitro analysis of the enzyme activity. Additionally, structure-guided site-directed mutagenesis of SeCobT broadened its substrate specificity to include phenolic bases, revealing likely evolutionary changes needed to increase cobamide diversity, and further supporting the proposed mechanism for the phosphoribosylation of phenolic substrates. GENERAL SIGNIFICANCE Results of this study uncover key residues in the CobT enzyme that contribute to the diversity of cobamides in nature.
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Hazra AB, Tran JLA, Crofts TS, Taga ME. Analysis of substrate specificity in CobT homologs reveals widespread preference for DMB, the lower axial ligand of vitamin B(12). ACTA ACUST UNITED AC 2013; 20:1275-85. [PMID: 24055005 DOI: 10.1016/j.chembiol.2013.08.007] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2013] [Revised: 07/02/2013] [Accepted: 08/05/2013] [Indexed: 10/26/2022]
Abstract
Cobamides such as vitamin B12 (cobalamin) are produced exclusively by prokaryotes and used by many other organisms as cofactors for diverse metabolic processes. Cobamides are cobalt-containing tetrapyrroles with upper and lower axial ligands. The structure of the lower ligand varies in cobamides produced by different bacteria. We investigated the biochemical basis of this structural variability by exploring the reactivity of homologs of CobT, the enzyme responsible for activating lower ligand bases for incorporation into cobamides. Our results show that CobT enzymes can activate a range of lower ligand substrates, and the majority of the enzymes tested preferentially attach 5,6-dimethylbenzimidazole (DMB), the lower ligand of cobalamin. This suggests that many bacteria that synthesize cobamides other than cobalamin in pure culture may produce cobalamin in mixed communities by attaching DMB when it is available in the environment.
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Affiliation(s)
- Amrita B Hazra
- Department of Plant and Microbial Biology, University of California, Berkeley, Berkeley, CA 94720, USA
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Diversity of cobalamin riboswitches in the corrinoid-producing organohalide respirer Desulfitobacterium hafniense. J Bacteriol 2013; 195:5186-95. [PMID: 24039263 DOI: 10.1128/jb.00730-13] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
The strategic adaptation of prokaryotes in polluted niches involves the efficient regulation of their metabolism. The obligate anaerobe and metabolically versatile Desulfitobacterium hafniense reductively dechlorinates halogenated organic compounds (so-called organohalides). Some D. hafniense strains carry out organohalide respiration (OHR), a process which requires the use of corrinoid as a cofactor in reductive dehalogenases, the key enzymes in OHR. We report here the diversity of the cobalamin riboswitches that possibly regulate the corrinoid metabolism for D. hafniense. The analysis of available D. hafniense genomes indicates the presence of 18 cobalamin riboswitches located upstream of genes whose products are mainly involved in corrinoid biosynthesis and transport. To obtain insight into their function, the secondary structures of three of these RNA elements were predicted by Mfold, as well as analyzed by in-line probing. These RNA elements both display diversity in their structural elements and exhibit various affinities toward adenosylcobalamin that possibly relates to their role in the regulation of corrinoid metabolism. Furthermore, adenosylcobalamin-induced in vivo repression of RNA synthesis of the downstream located genes indicates that the corrinoid transporters and biosynthetic enzymes in D. hafniense strain TCE1 are regulated at the transcriptional level. Taken together, the riboswitch-mediated regulation of the complex corrinoid metabolism in D. hafniense could be of crucial significance in environments polluted with organohalides both to monitor their intracellular corrinoid level and to coexist with corrinoid-auxotroph OHR bacteria.
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de Crécy-Lagard V, Forouhar F, Brochier-Armanet C, Tong L, Hunt JF. Comparative genomic analysis of the DUF71/COG2102 family predicts roles in diphthamide biosynthesis and B12 salvage. Biol Direct 2012; 7:32. [PMID: 23013770 PMCID: PMC3541065 DOI: 10.1186/1745-6150-7-32] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2012] [Accepted: 09/18/2012] [Indexed: 01/09/2023] Open
Abstract
Background The availability of over 3000 published genome sequences has enabled the use of comparative genomic approaches to drive the biological function discovery process. Classically, one used to link gene with function by genetic or biochemical approaches, a lengthy process that often took years. Phylogenetic distribution profiles, physical clustering, gene fusion, co-expression profiles, structural information and other genomic or post-genomic derived associations can be now used to make very strong functional hypotheses. Here, we illustrate this shift with the analysis of the DUF71/COG2102 family, a subgroup of the PP-loop ATPase family. Results The DUF71 family contains at least two subfamilies, one of which was predicted to be the missing diphthine-ammonia ligase (EC 6.3.1.14), Dph6. This enzyme catalyzes the last ATP-dependent step in the synthesis of diphthamide, a complex modification of Elongation Factor 2 that can be ADP-ribosylated by bacterial toxins. Dph6 orthologs are found in nearly all sequenced Archaea and Eucarya, as expected from the distribution of the diphthamide modification. The DUF71 family appears to have originated in the Archaea/Eucarya ancestor and to have been subsequently horizontally transferred to Bacteria. Bacterial DUF71 members likely acquired a different function because the diphthamide modification is absent in this Domain of Life. In-depth investigations suggest that some archaeal and bacterial DUF71 proteins participate in B12 salvage. Conclusions This detailed analysis of the DUF71 family members provides an example of the power of integrated data-miming for solving important “missing genes” or “missing function” cases and illustrates the danger of functional annotation of protein families by homology alone. Reviewers’ names This article was reviewed by Arcady Mushegian, Michael Galperin and L. Aravind.
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Affiliation(s)
- Valérie de Crécy-Lagard
- Department of Microbiology and Cell Science, University of Florida, Gainesville, FL 32611, USA.
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Yan J, Ritalahti KM, Wagner DD, Löffler FE. Unexpected specificity of interspecies cobamide transfer from Geobacter spp. to organohalide-respiring Dehalococcoides mccartyi strains. Appl Environ Microbiol 2012; 78:6630-6. [PMID: 22773645 PMCID: PMC3426716 DOI: 10.1128/aem.01535-12] [Citation(s) in RCA: 83] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2012] [Accepted: 07/03/2012] [Indexed: 11/20/2022] Open
Abstract
Dehalococcoides mccartyi strains conserve energy from reductive dechlorination reactions catalyzed by corrinoid-dependent reductive dehalogenase enzyme systems. Dehalococcoides lacks the ability for de novo corrinoid synthesis, and pure cultures require the addition of cyanocobalamin (vitamin B(12)) for growth. In contrast, Geobacter lovleyi, which dechlorinates tetrachloroethene to cis-1,2-dichloroethene (cis-DCE), and the nondechlorinating species Geobacter sulfurreducens have complete sets of cobamide biosynthesis genes and produced 12.9 ± 2.4 and 24.2 ± 5.8 ng of extracellular cobamide per liter of culture suspension, respectively, during growth with acetate and fumarate in a completely synthetic medium. G. lovleyi-D. mccartyi strain BAV1 or strain FL2 cocultures provided evidence for interspecies corrinoid transfer, and cis-DCE was dechlorinated to vinyl chloride and ethene concomitant with Dehalococcoides growth. In contrast, negligible increase in Dehalococcoides 16S rRNA gene copies and insignificant dechlorination occurred in G. sulfurreducens-D. mccartyi strain BAV1 or strain FL2 cocultures. Apparently, G. lovleyi produces a cobamide that complements Dehalococcoides' nutritional requirements, whereas G. sulfurreducens does not. Interestingly, Dehalococcoides dechlorination activity and growth could be restored in G. sulfurreducens-Dehalococcoides cocultures by adding 10 μM 5',6'-dimethylbenzimidazole. Observations made with the G. sulfurreducens-Dehalococcoides cocultures suggest that the exchange of the lower ligand generated a cobalamin, which supported Dehalococcoides activity. These findings have implications for in situ bioremediation and suggest that the corrinoid metabolism of Dehalococcoides must be understood to faithfully predict, and possibly enhance, reductive dechlorination activities.
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Affiliation(s)
- Jun Yan
- Department of Microbiology
- Department of Civil and Environmental Engineering, University of Tennessee, Knoxville, Tennessee, USA
| | - Kirsti M. Ritalahti
- Department of Microbiology
- Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee, USA
| | - Darlene D. Wagner
- School of Biology, Georgia Institute of Technology, Atlanta, Georgia, USA
| | - Frank E. Löffler
- Department of Microbiology
- Department of Civil and Environmental Engineering, University of Tennessee, Knoxville, Tennessee, USA
- Biosciences Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee, USA
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Versatility in corrinoid salvaging and remodeling pathways supports corrinoid-dependent metabolism in Dehalococcoides mccartyi. Appl Environ Microbiol 2012; 78:7745-52. [PMID: 22923412 DOI: 10.1128/aem.02150-12] [Citation(s) in RCA: 80] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023] Open
Abstract
Corrinoids are cobalt-containing molecules that function as enzyme cofactors in a wide variety of organisms but are produced solely by a subset of prokaryotes. Specific corrinoids are identified by the structure of their axial ligands. The lower axial ligand of a corrinoid can be a benzimidazole, purine, or phenolic compound. Though it is known that many organisms obtain corrinoids from the environment, the variety of corrinoids that can serve as cofactors for any one organism is largely unstudied. Here, we examine the range of corrinoids that function as cofactors for corrinoid-dependent metabolism in Dehalococcoides mccartyi strain 195. Dehalococcoides bacteria play an important role in the bioremediation of chlorinated solvents in the environment because of their unique ability to convert the common groundwater contaminants perchloroethene and trichloroethene to the innocuous end product ethene. All isolated D. mccartyi strains require exogenous corrinoids such as vitamin B(12) for growth. However, like many other corrinoid-dependent bacteria, none of the well-characterized D. mccartyi strains has been shown to be capable of synthesizing corrinoids de novo. In this study, we investigate the ability of D. mccartyi strain 195 to use specific corrinoids, as well as its ability to modify imported corrinoids to a functional form. We show that strain 195 can use only specific corrinoids containing benzimidazole lower ligands but is capable of remodeling other corrinoids by lower ligand replacement when provided a functional benzimidazole base. This study of corrinoid utilization and modification by D. mccartyi provides insight into the array of strategies that microorganisms employ in acquiring essential nutrients from the environment.
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Chan CH, Escalante-Semerena JC. ArsAB, a novel enzyme from Sporomusa ovata activates phenolic bases for adenosylcobamide biosynthesis. Mol Microbiol 2011; 81:952-67. [PMID: 21696461 DOI: 10.1111/j.1365-2958.2011.07741.x] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
In the homoacetogenic bacterium Sporomusa ovata, phenol and p-cresol are converted into α-ribotides, which are incorporated into biologically active cobamides (Cbas) whose lower ligand bases do not form axial co-ordination bonds with the cobalt ion of the corrin ring. Here we report the identity of two S. ovata genes that encode an enzyme that transfers the phosphoribosyl group of nicotinate mononucleotide (NaMN) to phenol or p-cresol, yielding α-O-glycosidic ribotides. The alluded genes were named arsA and arsB (for alpha-ribotide synthesis), arsA and arsB were isolated from a genomic DNA library of S. ovata. A positive selection strategy using an Escherichia coli strain devoid of NaMN:5,6-dimethylbenzimidazole (DMB) phosphoribosyltransferase (CobT) activity was used to isolate a fragment of S. ovata DNA that contained arsA and arsB, whose nucleotide sequences overlapped by 8 bp. SoArsAB was isolated to homogeneity, shown to be functional as a heterodimer, and to have highest activity at pH 9. SoArsAB also activated DMB to its α-N-glycosidic ribotide. Previously characterized CobT-like enzymes activate DMB but do not activate phenolics. NMR spectroscopy was used to confirm the incorporation of phenol into the cobamide, and mass spectrometry was used to identify SoArsAB reaction products.
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Affiliation(s)
- Chi Ho Chan
- Department of Bacteriology, University of Wisconsin, 1550 Linden Drive, Madison, WI 53706-1521, USA
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Newmister SA, Otte MM, Escalante-Semerena JC, Rayment I. Structure and mutational analysis of the archaeal GTP:AdoCbi-P guanylyltransferase (CobY) from Methanocaldococcus jannaschii: insights into GTP binding and dimerization. Biochemistry 2011; 50:5301-13. [PMID: 21542645 DOI: 10.1021/bi200329t] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
In archaea and bacteria, the late steps in adenosylcobalamin (AdoCbl) biosynthesis are collectively known as the nucleotide loop assembly (NLA) pathway. In the archaeal and bacterial NLA pathways, two different guanylyltransferases catalyze the activation of the corrinoid. Structural and functional studies of the bifunctional bacterial guanylyltransferase that catalyze both ATP-dependent corrinoid phosphorylation and GTP-dependent guanylylation are available, but similar studies of the monofunctional archaeal enzyme that catalyzes only GTP-dependent guanylylation are not. Herein, the three-dimensional crystal structure of the guanylyltransferase (CobY) enzyme from the archaeon Methanocaldococcus jannaschii (MjCobY) in complex with GTP is reported. The model identifies the location of the active site. An extensive mutational analysis was performed, and the functionality of the variant proteins was assessed in vivo and in vitro. Substitutions of residues Gly8, Gly153, or Asn177 resulted in ≥94% loss of catalytic activity; thus, variant proteins failed to support AdoCbl synthesis in vivo. Results from isothermal titration calorimetry experiments showed that MjCobY(G153D) had 10-fold higher affinity for GTP than MjCobY(WT) but failed to bind the corrinoid substrate. Results from Western blot analyses suggested that the above-mentioned substitutions render the protein unstable and prone to degradation; possible explanations for the observed instability of the variants are discussed within the framework of the three-dimensional crystal structure of MjCobY(G153D) in complex with GTP. The fold of MjCobY is strikingly similar to that of the N-terminal domain of Mycobacterium tuberculosis GlmU (MtbGlmU), a bifunctional acetyltransferase/uridyltransferase that catalyzes the formation of uridine diphosphate-N-acetylglucosamine (UDP-GlcNAc).
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Affiliation(s)
- Sean A Newmister
- Department of Biochemistry, University of Wisconsin , Madison, WI 53706, USA
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Gray MJ, Escalante-Semerena JC. A new pathway for the synthesis of α-ribazole-phosphate in Listeria innocua. Mol Microbiol 2010; 77:1429-38. [PMID: 20633228 PMCID: PMC2948856 DOI: 10.1111/j.1365-2958.2010.07294.x] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The genomes of Listeria spp. encode all but one of 25 enzymes required for the biosynthesis of adenosylcobalamin (AdoCbl; coenzyme B(12) ). Notably, all Listeria genomes lack CobT, the nicotinamide mononucleotide:5,6-dimethylbenzimidazole (DMB) phosphoribosyltransferase (EC 2.4.2.21) enzyme that synthesizes the unique α-linked nucleotide N(1) -(5-phospho-α-D-ribosyl)-DMB (α-ribazole-5'-P, α-RP), a precursor of AdoCbl. We have uncovered a new pathway for the synthesis of α-RP in Listeria innocua that circumvents the lack of CobT. The cblT and cblS genes (locus tags lin1153 and lin1110) of L. innocua encode an α-ribazole (α-R) transporter and an α-R kinase respectively. Results from in vivo experiments indicate that L. innocua depends on CblT and CblS activities to salvage exogenous α-R, allowing conversion of the incomplete corrinoid cobinamide (Cbi) into AdoCbl. Expression of the L. innocua cblT and cblS genes restored AdoCbl synthesis from Cbi and α-R in a Salmonella enterica cobT strain. LinCblT transported α-R across the cell membrane, but not α-RP or DMB. UV-visible spectroscopy and mass spectrometry data identified α-RP as the product of the ATP-dependent α-R kinase activity of LinCblS. Bioinformatics analyses suggest that α-R salvaging occurs in important Gram-positive human pathogens.
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Affiliation(s)
- Michael J Gray
- Department of Bacteriology, University of Wisconsin, 6478 Microbial Sciences Building, 1550 Linden Drive, Madison, WI 53706, USA
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