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Jallet D, Soldan V, Shayan R, Stella A, Ismail N, Zenati R, Cahoreau E, Burlet-Schiltz O, Balor S, Millard P, Heux S. Integrative in vivo analysis of the ethanolamine utilization bacterial microcompartment in Escherichia coli. mSystems 2024; 9:e0075024. [PMID: 39023255 PMCID: PMC11334477 DOI: 10.1128/msystems.00750-24] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2024] [Accepted: 06/12/2024] [Indexed: 07/20/2024] Open
Abstract
Bacterial microcompartments (BMCs) are self-assembling protein megacomplexes that encapsulate metabolic pathways. Although approximately 20% of sequenced bacterial genomes contain operons encoding putative BMCs, few have been thoroughly characterized, nor any in the most studied Escherichia coli strains. We used an interdisciplinary approach to gain deep molecular and functional insights into the ethanolamine utilization (Eut) BMC system encoded by the eut operon in E. coli K-12. The eut genotype was linked with the ethanolamine utilization phenotype using deletion and overexpression mutants. The subcellular dynamics and morphology of the E. coli Eut BMCs were characterized in cellula by fluorescence microscopy and electron (cryo)microscopy. The minimal proteome reorganization required for ethanolamine utilization and the in vivo stoichiometric composition of the Eut BMC were determined by quantitative proteomics. Finally, the first flux map connecting the Eut BMC with central metabolism in cellula was obtained by genome-scale modeling and 13C-fluxomics. Our results reveal that contrary to previous suggestions, ethanolamine serves both as a nitrogen and a carbon source in E. coli K-12, while also contributing to significant metabolic overflow. Overall, this study provides a quantitative molecular and functional understanding of the BMCs involved in ethanolamine assimilation by E. coli.IMPORTANCEThe properties of bacterial microcompartments make them an ideal tool for building orthogonal network structures with minimal interactions with native metabolic and regulatory networks. However, this requires an understanding of how BMCs work natively. In this study, we combined genetic manipulation, multi-omics, modeling, and microscopy to address this issue for Eut BMCs. We show that the Eut BMC in Escherichia coli turns ethanolamine into usable carbon and nitrogen substrates to sustain growth. These results improve our understanding of compartmentalization in a widely used bacterial chassis.
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Affiliation(s)
- Denis Jallet
- Toulouse Biotechnology Institute, Université de Toulouse, CNRS, INRAE, INSA, Toulouse, France
| | - Vanessa Soldan
- Plateforme de Microscopie Electronique Intégrative, Centre de Biologie Intégrative, Université de Toulouse, CNRS, Toulouse, France
| | - Ramteen Shayan
- Plateforme de Microscopie Electronique Intégrative, Centre de Biologie Intégrative, Université de Toulouse, CNRS, Toulouse, France
| | - Alexandre Stella
- Institut de Pharmacologie et de Biologie Structurale (IPBS), Université de Toulouse, CNRS, Université Toulouse III—Paul Sabatier (UT3), Toulouse, France
- Infrastructure nationale de protéomique, ProFI, Toulouse, France
| | - Nour Ismail
- Toulouse Biotechnology Institute, Université de Toulouse, CNRS, INRAE, INSA, Toulouse, France
| | - Rania Zenati
- Toulouse Biotechnology Institute, Université de Toulouse, CNRS, INRAE, INSA, Toulouse, France
| | - Edern Cahoreau
- Toulouse Biotechnology Institute, Université de Toulouse, CNRS, INRAE, INSA, Toulouse, France
- MetaToul-MetaboHUB, National infrastructure of metabolomics and fluxomics, Toulouse, France
| | - Odile Burlet-Schiltz
- Institut de Pharmacologie et de Biologie Structurale (IPBS), Université de Toulouse, CNRS, Université Toulouse III—Paul Sabatier (UT3), Toulouse, France
- Infrastructure nationale de protéomique, ProFI, Toulouse, France
| | - Stéphanie Balor
- Plateforme de Microscopie Electronique Intégrative, Centre de Biologie Intégrative, Université de Toulouse, CNRS, Toulouse, France
| | - Pierre Millard
- Toulouse Biotechnology Institute, Université de Toulouse, CNRS, INRAE, INSA, Toulouse, France
- MetaToul-MetaboHUB, National infrastructure of metabolomics and fluxomics, Toulouse, France
| | - Stéphanie Heux
- Toulouse Biotechnology Institute, Université de Toulouse, CNRS, INRAE, INSA, Toulouse, France
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Chatterjee A, Kaval KG, Garsin DA. Role of ethanolamine utilization and bacterial microcompartment formation in Listeria monocytogenes intracellular infection. Infect Immun 2024; 92:e0016224. [PMID: 38752742 PMCID: PMC11237587 DOI: 10.1128/iai.00162-24] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2024] [Accepted: 04/18/2024] [Indexed: 05/28/2024] Open
Abstract
Ethanolamine (EA) affects the colonization and pathogenicity of certain human bacterial pathogens in the gastrointestinal tract. However, EA can also affect the intracellular survival and replication of host cell invasive bacteria such as Listeria monocytogenes (LMO) and Salmonella enterica serovar Typhimurium (S. Typhimurium). The EA utilization (eut) genes can be categorized as regulatory, enzymatic, or structural, and previous work in LMO showed that loss of genes encoding functions for the enzymatic breakdown of EA inhibited LMO intracellular replication. In this work, we sought to further characterize the role of EA utilization during LMO infection of host cells. Unlike what was previously observed for S. Typhimurium, in LMO, an EA regulator mutant (ΔeutV) was equally deficient in intracellular replication compared to an EA metabolism mutant (ΔeutB), and this was consistent across Caco-2, RAW 264.7, and THP-1 cell lines. The structural genes encode proteins that self-assemble into bacterial microcompartments (BMCs) that encase the enzymes necessary for EA metabolism. For the first time, native EUT BMCs were fluorescently tagged, and EUT BMC formation was observed in vitro and in vivo. Interestingly, BMC formation was observed in bacteria infecting Caco-2 cells, but not the macrophage cell lines. Finally, the cellular immune response of Caco-2 cells to infection with eut mutants was examined, and it was discovered that ΔeutB and ΔeutV mutants similarly elevated the expression of inflammatory cytokines. In conclusion, EA sensing and utilization during LMO intracellular infection are important for optimal LMO replication and immune evasion but are not always concomitant with BMC formation.IMPORTANCEListeria monocytogenes (LMO) is a bacterial pathogen that can cause severe disease in immunocompromised individuals when consumed in contaminated food. It can replicate inside of mammalian cells, escaping detection by the immune system. Therefore, understanding the features of this human pathogen that contribute to its infectiousness and intracellular lifestyle is important. In this work we demonstrate that genes encoding both regulators and enzymes of EA metabolism are important for optimal growth inside mammalian cells. Moreover, the formation of specialized compartments to enable EA metabolism were visualized by tagging with a fluorescent protein and found to form when LMO infects some mammalian cell types, but not others. Interestingly, the formation of the compartments was associated with features consistent with an early stage of the intracellular infection. By characterizing bacterial metabolic pathways that contribute to survival in host environments, we hope to positively impact knowledge and facilitate new treatment strategies.
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Affiliation(s)
- Ayan Chatterjee
- Department of Microbiology and Molecular Genetics, The University of Texas Health Science Center, Houston, Texas, USA
| | - Karan Gautam Kaval
- Department of Microbiology and Molecular Genetics, The University of Texas Health Science Center, Houston, Texas, USA
| | - Danielle A Garsin
- Department of Microbiology and Molecular Genetics, The University of Texas Health Science Center, Houston, Texas, USA
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3
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Shen W, Downs DM. Tetrahydrofolate levels influence 2-aminoacrylate stress in Salmonella enterica. J Bacteriol 2024; 206:e0004224. [PMID: 38563759 PMCID: PMC11025330 DOI: 10.1128/jb.00042-24] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2024] [Accepted: 03/12/2024] [Indexed: 04/04/2024] Open
Abstract
In Salmonella enterica, the absence of the RidA deaminase results in the accumulation of the reactive enamine 2-aminoacrylate (2AA). The resulting 2AA stress impacts metabolism and prevents growth in some conditions by inactivating a specific target pyridoxal 5'-phosphate (PLP)-dependent enzyme(s). The detrimental effects of 2AA stress can be overcome by changing the sensitivity of a critical target enzyme or modifying flux in one or more nodes in the metabolic network. The catabolic L-alanine racemase DadX is a target of 2AA, which explains the inability of an alr ridA strain to use L-alanine as the sole nitrogen source. Spontaneous mutations that suppressed the growth defect of the alr ridA strain were identified as lesions in folE, which encodes GTP cyclohydrolase and catalyzes the first step of tetrahydrofolate (THF) synthesis. The data here show that THF limitation resulting from a folE lesion, or inhibition of dihydrofolate reductase (FolA) by trimethoprim, decreases the 2AA generated from endogenous serine. The data are consistent with an increased level of threonine, resulting from low folate levels, decreasing 2AA stress.IMPORTANCERidA is an enamine deaminase that has been characterized as preventing the 2-aminoacrylate (2AA) stress. In the absence of RidA, 2AA accumulates and damages various cellular enzymes. Much of the work describing the 2AA stress system has depended on the exogenous addition of serine to increase the production of the enamine stressor. The work herein focuses on understanding the effect of 2AA stress generated from endogenous serine pools. As such, this work describes the consequences of a subtle level of stress that nonetheless compromises growth in at least two conditions. Describing mechanisms that alter the physiological consequences of 2AA stress increases our understanding of endogenous metabolic stress and how the robustness of the metabolic network allows perturbations to be modulated.
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Affiliation(s)
- Wangchen Shen
- Department of Microbiology, University of Georgia, Athens, Georgia, USA
| | - Diana M. Downs
- Department of Microbiology, University of Georgia, Athens, Georgia, USA
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Chatterjee A, Kaval KG, Garsin DA. Role of Ethanolamine Utilization and Bacterial Microcompartment Formation in Listeria monocytogenes Intracellular Infection. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2023.12.19.572424. [PMID: 38187703 PMCID: PMC10769209 DOI: 10.1101/2023.12.19.572424] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/09/2024]
Abstract
Ethanolamine (EA) affects the colonization and pathogenicity of certain human bacterial pathogens in the gastrointestinal tract. However, EA can also affect the intracellular survival and replication of host-cell invasive bacteria such as Listeria monocytogenes (LMO) and Salmonella enterica serovar Typhimurium ( S. Typhimurium). The EA utilization ( eut) genes can be categorized as regulatory, enzymatic, or structural, and previous work in LMO showed that loss of genes encoding functions for the enzymatic breakdown of EA inhibited LMO intracellular replication. In this work, we sought to further characterize the role of EA utilization during LMO infection of host cells. Unlike what was previously observed for S. Typhimurium, in LMO, an EA regulator mutant ( ΔeutV) was equally deficient in intracellular replication compared to an EA metabolism mutant ( ΔeutB ), and this was consistent across Caco-2, RAW 264.7 and THP-1 cell lines. The structural genes encode proteins that self-assemble into bacterial microcompartments (BMCs) that encase the enzymes necessary for EA metabolism. For the first time, native EUT BMCs were fluorescently tagged, and EUT BMC formation was observed in vitro, and in vivo. Interestingly, BMC formation was observed in bacteria infecting Caco-2 cells, but not the macrophage cell lines. Finally, the cellular immune response of Caco-2 cells to infection with eut mutants was examined, and it was discovered that ΔeutB and ΔeutV mutants similarly elevated the expression of inflammatory cytokines. In conclusion, EA sensing and utilization during LMO intracellular infection are important for optimal LMO replication and immune evasion but are not always concomitant with BMC formation.
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Maurer JJ, Cheng Y, Pedroso A, Thompson KK, Akter S, Kwan T, Morota G, Kinstler S, Porwollik S, McClelland M, Escalante-Semerena JC, Lee MD. Peeling back the many layers of competitive exclusion. Front Microbiol 2024; 15:1342887. [PMID: 38591029 PMCID: PMC11000858 DOI: 10.3389/fmicb.2024.1342887] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2023] [Accepted: 02/19/2024] [Indexed: 04/10/2024] Open
Abstract
Baby chicks administered a fecal transplant from adult chickens are resistant to Salmonella colonization by competitive exclusion. A two-pronged approach was used to investigate the mechanism of this process. First, Salmonella response to an exclusive (Salmonella competitive exclusion product, Aviguard®) or permissive microbial community (chicken cecal contents from colonized birds containing 7.85 Log10Salmonella genomes/gram) was assessed ex vivo using a S. typhimurium reporter strain with fluorescent YFP and CFP gene fusions to rrn and hilA operon, respectively. Second, cecal transcriptome analysis was used to assess the cecal communities' response to Salmonella in chickens with low (≤5.85 Log10 genomes/g) or high (≥6.00 Log10 genomes/g) Salmonella colonization. The ex vivo experiment revealed a reduction in Salmonella growth and hilA expression following co-culture with the exclusive community. The exclusive community also repressed Salmonella's SPI-1 virulence genes and LPS modification, while the anti-virulence/inflammatory gene avrA was upregulated. Salmonella transcriptome analysis revealed significant metabolic disparities in Salmonella grown with the two different communities. Propanediol utilization and vitamin B12 synthesis were central to Salmonella metabolism co-cultured with either community, and mutations in propanediol and vitamin B12 metabolism altered Salmonella growth in the exclusive community. There were significant differences in the cecal community's stress response to Salmonella colonization. Cecal community transcripts indicated that antimicrobials were central to the type of stress response detected in the low Salmonella abundance community, suggesting antagonism involved in Salmonella exclusion. This study indicates complex community interactions that modulate Salmonella metabolism and pathogenic behavior and reduce growth through antagonism may be key to exclusion.
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Affiliation(s)
- John J. Maurer
- School of Animal Sciences, College of Veterinary Medicine, Virginia Polytechnic Institute and State University, Blacksburg, VA, United States
| | - Ying Cheng
- Department of Population Health, University of Georgia, Athens, GA, United States
| | - Adriana Pedroso
- Department of Population Health, University of Georgia, Athens, GA, United States
| | - Kasey K. Thompson
- Department of Population Health, University of Georgia, Athens, GA, United States
| | - Shamima Akter
- Department of Biomedical Sciences and Pathobiology, College of Veterinary Medicine, Virginia Polytechnic Institute and State University, Blacksburg, VA, United States
| | - Tiffany Kwan
- Department of Population Health, University of Georgia, Athens, GA, United States
| | - Gota Morota
- School of Animal Sciences, College of Veterinary Medicine, Virginia Polytechnic Institute and State University, Blacksburg, VA, United States
| | - Sydney Kinstler
- School of Animal Sciences, College of Veterinary Medicine, Virginia Polytechnic Institute and State University, Blacksburg, VA, United States
| | - Steffen Porwollik
- Department of Microbiology and Molecular Genetics, University of California, Irvine, Irvine, CA, United States
| | - Michael McClelland
- Department of Microbiology and Molecular Genetics, University of California, Irvine, Irvine, CA, United States
| | | | - Margie D. Lee
- Department of Biomedical Sciences and Pathobiology, College of Veterinary Medicine, Virginia Polytechnic Institute and State University, Blacksburg, VA, United States
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Ochoa JM, Dershwitz P, Schappert M, Sinha S, Herring TI, Yeates TO, Bobik TA. A single shell protein plays a major role in choline transport across the shell of the choline utilization microcompartment of Escherichia coli 536. MICROBIOLOGY (READING, ENGLAND) 2023; 169:001413. [PMID: 37971493 PMCID: PMC10710832 DOI: 10.1099/mic.0.001413] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/25/2023] [Accepted: 10/30/2023] [Indexed: 11/19/2023]
Abstract
Bacterial microcompartments (MCPs) are widespread protein-based organelles that play important roles in the global carbon cycle and in the physiology of diverse bacteria, including a number of pathogens. MCPs consist of metabolic enzymes encapsulated within a protein shell. The main roles of MCPs are to concentrate enzymes together with their substrates (to increase reaction rates) and to sequester harmful metabolic intermediates. Prior studies indicate that MCPs have a selectively permeable protein shell, but the mechanisms that allow selective transport across the shell are not fully understood. Here we examine transport across the shell of the choline utilization (Cut) MCP of Escherichia coli 536, which has not been studied before. The shell of the Cut MCP is unusual in consisting of one pentameric and four hexameric bacterial microcompartment (BMC) domain proteins. It lacks trimeric shell proteins, which are thought to be required for the transport of larger substrates and enzymatic cofactors. In addition, its four hexameric BMC domain proteins are very similar in amino acid sequence. This raises questions about how the Cut MCP mediates the selective transport of the substrate, products and cofactors of choline metabolism. In this report, site-directed mutagenesis is used to modify the central pores (the main transport channels) of all four Cut BMC hexamers to assess their transport roles. Our findings indicate that a single shell protein, CmcB, plays the major role in choline transport across the shell of the Cut MCP and that the electrostatic properties of the CmcB pore also impact choline transport. The implications of these findings with regard to the higher-order structure of MCPs are discussed.
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Affiliation(s)
- Jessica M. Ochoa
- UCLA-Molecular Biology Institute, University of California, Los Angeles, USA
| | - Philip Dershwitz
- Roy J. Carver Department of Biochemistry, Biophysics and Molecular Biology, Iowa State University, Ames, IA, 50011, USA
| | - Mary Schappert
- Roy J. Carver Department of Biochemistry, Biophysics and Molecular Biology, Iowa State University, Ames, IA, 50011, USA
| | - Sharmistha Sinha
- Roy J. Carver Department of Biochemistry, Biophysics and Molecular Biology, Iowa State University, Ames, IA, 50011, USA
| | - Taylor I. Herring
- Roy J. Carver Department of Biochemistry, Biophysics and Molecular Biology, Iowa State University, Ames, IA, 50011, USA
| | - Todd O. Yeates
- UCLA-Molecular Biology Institute, University of California, Los Angeles, USA
- UCLA-DOE Institute for Genomics and Proteomics, Los Angeles, USA
- Department of Chemistry and Biochemistry, University of California, Los Angeles, USA
| | - Thomas A. Bobik
- Roy J. Carver Department of Biochemistry, Biophysics and Molecular Biology, Iowa State University, Ames, IA, 50011, USA
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Moreira de Gouveia MI, Daniel J, Garrivier A, Bernalier-Donadille A, Jubelin G. Diversity of ethanolamine utilization by human commensal Escherichiacoli. Res Microbiol 2023; 174:103989. [PMID: 35988812 DOI: 10.1016/j.resmic.2022.103989] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2022] [Revised: 08/03/2022] [Accepted: 08/05/2022] [Indexed: 01/11/2023]
Abstract
Ethanolamine (EA) is a substrate naturally present in the human gut and its catabolism by bacteria relies on the presence of eut genes encoding specific metabolic enzymes and accessory proteins. To date, EA utilization has been mostly investigated in gut bacterial pathogens. The aim of this study was to evaluate the ability of human gut commensal Escherichia coli isolates to utilize EA as a nitrogen and/or carbon sources. Although the capacity to consume EA is heterogeneous between the 40 strains of our collection, we determined that most of them could degrade EA to generate ammonia, a useful nitrogen resource for growth. Three isolates were also able to exploit EA as a carbon source. We also revealed that the inability of some strains to catabolize EA is explained either by mutations in the eut locus or by a defect in gene transcription. Finally, we demonstrated the importance of EA utilization for an optimal fitness of commensal E. coli in vivo. Our study provides new insights on the diversity of commensal E. coli strains to utilize EA as a nutrient in the gut and opens the way for new research in the field of interactions between host, gut microbiota and pathogens.
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Affiliation(s)
| | - Julien Daniel
- Université Clermont Auvergne, INRAE, MEDIS UMR454, F-63000, Clermont-Ferrand, France.
| | - Annie Garrivier
- Université Clermont Auvergne, INRAE, MEDIS UMR454, F-63000, Clermont-Ferrand, France.
| | | | - Gregory Jubelin
- Université Clermont Auvergne, INRAE, MEDIS UMR454, F-63000, Clermont-Ferrand, France.
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8
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Costa FG, Escalante-Semerena JC. Localization and interaction studies of the Salmonella enterica ethanolamine ammonia-lyase (EutBC), its reactivase (EutA), and the EutT corrinoid adenosyltransferase. Mol Microbiol 2022; 118:191-207. [PMID: 35785499 PMCID: PMC9481676 DOI: 10.1111/mmi.14962] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2022] [Revised: 06/29/2022] [Accepted: 06/30/2022] [Indexed: 11/28/2022]
Abstract
Some prokaryotes compartmentalize select metabolic capabilities. Salmonella enterica subspecies enterica serovar Typhimurium LT2 (hereafter S. Typhimurium) catabolizes ethanolamine (EA) within a proteinaceous compartment that we refer to as the ethanolamine utilization (Eut) metabolosome. EA catabolism is initiated by the adenosylcobalamin (AdoCbl)-dependent ethanolamine ammonia-lyase (EAL), which deaminates EA via an adenosyl radical mechanism to yield acetaldehyde plus ammonia. This adenosyl radical can be quenched, requiring the replacement of AdoCbl by the ATP-dependent EutA reactivase. During growth on ethanolamine, S. Typhimurium synthesizes AdoCbl from cobalamin (Cbl) using the ATP:Co(I)rrinoid adenosyltransferase (ACAT) EutT. It is known that EAL localizes to the metabolosome, however, prior to this work, it was unclear where EutA and EutT localized, and whether they interacted with EAL. Here, we provide evidence that EAL, EutA, and EutT localize to the Eut metabolosome, and that EutA interacts directly with EAL. We did not observe interactions between EutT and EAL nor between EutT and the EutA/EAL complex. However, growth phenotypes of a ΔeutT mutant strain show that EutT is critical for efficient ethanolamine catabolism. This work provides a preliminary understanding of the dynamics of AdoCbl synthesis and its uses within the Eut metabolosome.
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Affiliation(s)
- Flavia G. Costa
- Department of Microbiology, University of Georgia, Athens, GA, USA 30602
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Krysenko S, Wohlleben W. Polyamine and Ethanolamine Metabolism in Bacteria as an Important Component of Nitrogen Assimilation for Survival and Pathogenicity. Med Sci (Basel) 2022; 10:40. [PMID: 35997332 PMCID: PMC9397018 DOI: 10.3390/medsci10030040] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2022] [Revised: 07/23/2022] [Accepted: 07/25/2022] [Indexed: 11/16/2022] Open
Abstract
Nitrogen is an essential element required for bacterial growth. It serves as a building block for the biosynthesis of macromolecules and provides precursors for secondary metabolites. Bacteria have developed the ability to use various nitrogen sources and possess two enzyme systems for nitrogen assimilation involving glutamine synthetase/glutamate synthase and glutamate dehydrogenase. Microorganisms living in habitats with changeable availability of nutrients have developed strategies to survive under nitrogen limitation. One adaptation is the ability to acquire nitrogen from alternative sources including the polyamines putrescine, cadaverine, spermidine and spermine, as well as the monoamine ethanolamine. Bacterial polyamine and monoamine metabolism is not only important under low nitrogen availability, but it is also required to survive under high concentrations of these compounds. Such conditions can occur in diverse habitats such as soil, plant tissues and human cells. Strategies of pathogenic and non-pathogenic bacteria to survive in the presence of poly- and monoamines offer the possibility to combat pathogens by using their capability to metabolize polyamines as an antibiotic drug target. This work aims to summarize the knowledge on poly- and monoamine metabolism in bacteria and its role in nitrogen metabolism.
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Affiliation(s)
- Sergii Krysenko
- Interfaculty Institute of Microbiology and Infection Medicine Tübingen (IMIT), Department of Microbiology and Biotechnology, University of Tübingen, Auf der Morgenstelle 28, 72076 Tübingen, Germany;
- Cluster of Excellence ‘Controlling Microbes to Fight Infections’, University of Tübingen, 72076 Tübingen, Germany
| | - Wolfgang Wohlleben
- Interfaculty Institute of Microbiology and Infection Medicine Tübingen (IMIT), Department of Microbiology and Biotechnology, University of Tübingen, Auf der Morgenstelle 28, 72076 Tübingen, Germany;
- Cluster of Excellence ‘Controlling Microbes to Fight Infections’, University of Tübingen, 72076 Tübingen, Germany
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10
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Acinetobacter baumannii Catabolizes Ethanolamine in the Absence of a Metabolosome and Converts Cobinamide into Adenosylated Cobamides. mBio 2022; 13:e0179322. [PMID: 35880884 PMCID: PMC9426561 DOI: 10.1128/mbio.01793-22] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022] Open
Abstract
Acinetobacter baumannii is an opportunistic pathogen typically associated with hospital-acquired infections. Our understanding of the metabolism and physiology of A. baumannii is limited. Here, we report that A. baumannii uses ethanolamine (EA) as the sole source of nitrogen and can use this aminoalcohol as a source of carbon and energy if the expression of the eutBC genes encoding ethanolamine ammonia-lyase (EAL) is increased. A strain with an ISAba1 element upstream of the eutBC genes efficiently used EA as a carbon and energy source. The A. baumannii EAL (AbEAL) enzyme supported the growth of a strain of Salmonella lacking the entire eut operon. Remarkably, the growth of the above-mentioned Salmonella strain did not require the metabolosome, the reactivase EutA enzyme, the EutE acetaldehyde dehydrogenase, or the addition of glutathione to the medium. Transmission electron micrographs showed that when Acinetobacter baumannii or Salmonella enterica subsp. enterica serovar Typhimurium strain LT2 synthesized AbEAL, the protein localized to the cell membrane. We also report that the A. baumannii genome encodes all of the enzymes needed for the assembly of the nucleotide loop of cobamides and that it uses these enzymes to synthesize different cobamides from the precursor cobinamide and several nucleobases. In the absence of exogenous nucleobases, the most abundant cobamide produced by A. baumannii was cobalamin.
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Caparco AA, Dautel DR, Champion JA. Protein Mediated Enzyme Immobilization. SMALL (WEINHEIM AN DER BERGSTRASSE, GERMANY) 2022; 18:e2106425. [PMID: 35182030 DOI: 10.1002/smll.202106425] [Citation(s) in RCA: 19] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/21/2021] [Revised: 12/22/2021] [Indexed: 06/14/2023]
Abstract
Enzyme immobilization is an essential technology for commercializing biocatalysis. It imparts stability, recoverability, and other valuable features that improve the effectiveness of biocatalysts. While many avenues to join an enzyme to solid phases exist, protein-mediated immobilization is rapidly developing and has many advantages. Protein-mediated immobilization allows for the binding interaction to be genetically coded, can be used to create artificial multienzyme cascades, and enables modular designs that expand the variety of enzymes immobilized. By designing around binding interactions between protein domains, they can be integrated into functional materials for protein immobilization. These materials are framed within the context of biocatalytic performance, immobilization efficiency, and stability of the materials. In this review, supports composed entirely of protein are discussed first, with systems such as cellulosomes and protein cages being discussed alongside newer technologies like spore-based biocatalysts and forizymes. Protein-composite materials such as polymersomes and protein-inorganic supraparticles are then discussed to demonstrate how protein-mediated strategies are applied to many classes of solid materials. Critical analysis and future directions of protein-based immobilization are then discussed, with a particular focus on both computational and design strategies to advance this area of research and make it more broadly applicable to many classes of enzymes.
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Affiliation(s)
- Adam A Caparco
- Department of Nanoengineering, University of California, San Diego, MC 0448, 9500 Gilman Drive, La Jolla, CA, 92093, USA
| | - Dylan R Dautel
- School of Chemical and Biomolecular Engineering, Georgia Institute of Technology, 950 Atlantic Drive NW, Atlanta, GA, 30332, USA
| | - Julie A Champion
- School of Chemical and Biomolecular Engineering, Georgia Institute of Technology, 950 Atlantic Drive NW, Atlanta, GA, 30332, USA
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12
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Burrichter AG, Dörr S, Bergmann P, Haiß S, Keller A, Fournier C, Franchini P, Isono E, Schleheck D. Bacterial microcompartments for isethionate desulfonation in the taurine-degrading human-gut bacterium Bilophila wadsworthia. BMC Microbiol 2021; 21:340. [PMID: 34903181 PMCID: PMC8667426 DOI: 10.1186/s12866-021-02386-w] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2021] [Accepted: 11/08/2021] [Indexed: 11/15/2022] Open
Abstract
Background Bilophila wadsworthia, a strictly anaerobic, sulfite-reducing bacterium and common member of the human gut microbiota, has been associated with diseases such as appendicitis and colitis. It is specialized on organosulfonate respiration for energy conservation, i.e., utilization of dietary and host-derived organosulfonates, such as taurine (2-aminoethansulfonate), as sulfite donors for sulfite respiration, producing hydrogen sulfide (H2S), an important intestinal metabolite that may have beneficial as well as detrimental effects on the colonic environment. Its taurine desulfonation pathway involves the glycyl radical enzyme (GRE) isethionate sulfite-lyase (IslAB), which cleaves isethionate (2-hydroxyethanesulfonate) into acetaldehyde and sulfite. Results We demonstrate that taurine metabolism in B. wadsworthia 3.1.6 involves bacterial microcompartments (BMCs). First, we confirmed taurine-inducible production of BMCs by proteomic, transcriptomic and ultra-thin sectioning and electron-microscopical analyses. Then, we isolated BMCs from taurine-grown cells by density-gradient ultracentrifugation and analyzed their composition by proteomics as well as by enzyme assays, which suggested that the GRE IslAB and acetaldehyde dehydrogenase are located inside of the BMCs. Finally, we are discussing the recycling of cofactors in the IslAB-BMCs and a potential shuttling of electrons across the BMC shell by a potential iron-sulfur (FeS) cluster-containing shell protein identified by sequence analysis. Conclusions We characterized a novel subclass of BMCs and broadened the spectrum of reactions known to take place enclosed in BMCs, which is of biotechnological interest. We also provided more details on the energy metabolism of the opportunistic pathobiont B. wadsworthia and on microbial H2S production in the human gut. Supplementary Information The online version contains supplementary material available at 10.1186/s12866-021-02386-w.
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Affiliation(s)
- Anna G Burrichter
- Department of Biology, University of Konstanz, Konstanz, Germany. .,Konstanz Research School Chemical Biology, University of Konstanz, Konstanz, Germany. .,Max von Pettenkofer Institute of Hygiene and Medical Microbiology, Faculty of Medicine, LMU Munich, Munich, Germany.
| | - Stefanie Dörr
- Department of Biology, University of Konstanz, Konstanz, Germany
| | - Paavo Bergmann
- Electron Microscopy Centre, Department of Biology, University of Konstanz, Konstanz, Germany
| | - Sebastian Haiß
- Department of Biology, University of Konstanz, Konstanz, Germany
| | - Anja Keller
- Department of Biology, University of Konstanz, Konstanz, Germany.,Konstanz Research School Chemical Biology, University of Konstanz, Konstanz, Germany
| | | | - Paolo Franchini
- Department of Biology, University of Konstanz, Konstanz, Germany
| | - Erika Isono
- Department of Biology, University of Konstanz, Konstanz, Germany
| | - David Schleheck
- Department of Biology, University of Konstanz, Konstanz, Germany. .,Konstanz Research School Chemical Biology, University of Konstanz, Konstanz, Germany.
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13
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Huffine CA, Wheeler LC, Wing B, Cameron JC. Computational modeling and evolutionary implications of biochemical reactions in bacterial microcompartments. Curr Opin Microbiol 2021; 65:15-23. [PMID: 34717259 DOI: 10.1016/j.mib.2021.10.001] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2021] [Accepted: 10/02/2021] [Indexed: 11/19/2022]
Abstract
Bacterial microcompartments (BMCs) are protein-encapsulated compartments found across at least 23 bacterial phyla. BMCs contain a variety of metabolic processes that share the commonality of toxic or volatile intermediates, oxygen-sensitive enzymes and cofactors, or increased substrate concentration for magnified reaction rates. These compartmentalized reactions have been computationally modeled to explore the encapsulated dynamics, ask evolutionary-based questions, and develop a more systematic understanding required for the engineering of novel BMCs. Many crucial aspects of these systems remain unknown or unmeasured, such as substrate permeabilities across the protein shell, feasibility of pH gradients, and transport rates of associated substrates into the cell. This review explores existing BMC models, dominated in the literature by cyanobacterial carboxysomes, and highlights potentially important areas for exploration.
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Affiliation(s)
- Clair A Huffine
- BioFrontiers Institute, University of Colorado Boulder, 3415 Colorado Avenue, Boulder, CO 80309, USA; Department of Biochemistry, University of Colorado, Boulder, CO 80309, USA; Renewable and Sustainable Energy Institute, University of Colorado, Boulder, CO 80309, USA; Interdisciplinary Quantitative Biology Program (IQ Biology), BioFrontiers Institute, University of Colorado, Boulder, CO 80309, USA
| | - Lucas C Wheeler
- Department of Ecology and Evolutionary Biology, University of Colorado, Boulder, CO 80309, USA
| | - Boswell Wing
- Department of Geological Sciences, Boulder, CO 80309, USA
| | - Jeffrey C Cameron
- Department of Biochemistry, University of Colorado, Boulder, CO 80309, USA; Renewable and Sustainable Energy Institute, University of Colorado, Boulder, CO 80309, USA; National Renewable Energy Laboratory, Golden, CO 80401, USA.
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14
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Challenges and opportunities in biological funneling of heterogeneous and toxic substrates beyond lignin. Curr Opin Biotechnol 2021; 73:1-13. [PMID: 34242853 DOI: 10.1016/j.copbio.2021.06.007] [Citation(s) in RCA: 26] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2021] [Revised: 06/02/2021] [Accepted: 06/07/2021] [Indexed: 12/12/2022]
Abstract
Significant developments in the understanding and manipulation of microbial metabolism have enabled the use of engineered biological systems toward a more sustainable energy and materials economy. While developments in metabolic engineering have primarily focused on the conversion of carbohydrates, substantial opportunities exist for using these same principles to extract value from more heterogeneous and toxic waste streams, such as those derived from lignin, biomass pyrolysis, or industrial waste. Funneling heterogeneous substrates from these streams toward valuable products, termed biological funneling, presents new challenges in balancing multiple catabolic pathways competing for shared cellular resources and engineering against perturbation from toxic substrates. Solutions to many of these challenges have been explored within the field of lignin valorization. This perspective aims to extend beyond lignin to highlight the challenges and discuss opportunities for use of biological systems to upgrade previously inaccessible waste streams.
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15
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Sutter M, Melnicki MR, Schulz F, Woyke T, Kerfeld CA. A catalog of the diversity and ubiquity of bacterial microcompartments. Nat Commun 2021; 12:3809. [PMID: 34155212 PMCID: PMC8217296 DOI: 10.1038/s41467-021-24126-4] [Citation(s) in RCA: 50] [Impact Index Per Article: 16.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2021] [Accepted: 05/28/2021] [Indexed: 12/25/2022] Open
Abstract
Bacterial microcompartments (BMCs) are organelles that segregate segments of metabolic pathways which are incompatible with surrounding metabolism. BMCs consist of a selectively permeable shell, composed of three types of structurally conserved proteins, together with sequestered enzymes that vary among functionally distinct BMCs. Genes encoding shell proteins are typically clustered with those for the encapsulated enzymes. Here, we report that the number of identifiable BMC loci has increased twenty-fold since the last comprehensive census of 2014, and the number of distinct BMC types has doubled. The new BMC types expand the range of compartmentalized catalysis and suggest that there is more BMC biochemistry yet to be discovered. Our comprehensive catalog of BMCs provides a framework for their identification, correlation with bacterial niche adaptation, experimental characterization, and development of BMC-based nanoarchitectures for biomedical and bioengineering applications. Bacterial microcompartments (BMCs) are organelles consisting of a protein shell in which certain metabolic reactions take place separated from the cytoplasm. Here, Sutter et al. present a comprehensive catalog of BMC loci, substantially expanding the number of known BMCs and describing distinct types and compartmentalized reactions.
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Affiliation(s)
- Markus Sutter
- Environmental Genomics and Systems Biology and Molecular Biophysics and Integrative Bioimaging Divisions, Lawrence Berkeley National Laboratory, Berkeley, CA, USA.,MSU-DOE Plant Research Laboratory, Michigan State University, East Lansing, MI, USA
| | - Matthew R Melnicki
- MSU-DOE Plant Research Laboratory, Michigan State University, East Lansing, MI, USA
| | - Frederik Schulz
- DOE Joint Genome Institute, Lawrence Berkeley National Laboratory, Berkeley, CA, USA
| | - Tanja Woyke
- DOE Joint Genome Institute, Lawrence Berkeley National Laboratory, Berkeley, CA, USA
| | - Cheryl A Kerfeld
- Environmental Genomics and Systems Biology and Molecular Biophysics and Integrative Bioimaging Divisions, Lawrence Berkeley National Laboratory, Berkeley, CA, USA. .,MSU-DOE Plant Research Laboratory, Michigan State University, East Lansing, MI, USA. .,Department of Biochemistry and Molecular Biology, Michigan State University, East Lansing, MI, USA.
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16
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Functional compartmentalization and metabolic separation in a prokaryotic cell. Proc Natl Acad Sci U S A 2021; 118:2022114118. [PMID: 34161262 DOI: 10.1073/pnas.2022114118] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
The prokaryotic cell is traditionally seen as a "bag of enzymes," yet its organization is much more complex than in this simplified view. By now, various microcompartments encapsulating metabolic enzymes or pathways are known for Bacteria These microcompartments are usually small, encapsulating and concentrating only a few enzymes, thus protecting the cell from toxic intermediates or preventing unwanted side reactions. The hyperthermophilic, strictly anaerobic Crenarchaeon Ignicoccus hospitalis is an extraordinary organism possessing two membranes, an inner and an energized outer membrane. The outer membrane (termed here outer cytoplasmic membrane) harbors enzymes involved in proton gradient generation and ATP synthesis. These two membranes are separated by an intermembrane compartment, whose function is unknown. Major information processes like DNA replication, RNA synthesis, and protein biosynthesis are located inside the "cytoplasm" or central cytoplasmic compartment. Here, we show by immunogold labeling of ultrathin sections that enzymes involved in autotrophic CO2 assimilation are located in the intermembrane compartment that we name (now) a peripheric cytoplasmic compartment. This separation may protect DNA and RNA from reactive aldehydes arising in the I. hospitalis carbon metabolism. This compartmentalization of metabolic pathways and information processes is unprecedented in the prokaryotic world, representing a unique example of spatiofunctional compartmentalization in the second domain of life.
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17
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Liu LN. Bacterial metabolosomes: new insights into their structure and bioengineering. Microb Biotechnol 2021; 14:88-93. [PMID: 33404191 PMCID: PMC7888463 DOI: 10.1111/1751-7915.13740] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2020] [Accepted: 12/11/2020] [Indexed: 12/18/2022] Open
Abstract
Bacterial metabolosomes have been discovered for over 25 years. They play essential roles in bacterial metabolism and pathogenesis. In this crystal ball paper, I will discuss the recent advances in the fundamental understanding and synthetic engineering of bacterial metabolosomes.
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Affiliation(s)
- Lu-Ning Liu
- Institute of Systems, Molecular and Integrative Biology, University of Liverpool, Liverpool, L69 7ZB, UK.,College of Marine Life Sciences, Frontiers Science Center for Deep Ocean Multispheres and Earth System, Ocean University of China, Qingdao, 266003, China
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18
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Burin R, Shah DH. Global transcriptional profiling of tyramine and d-glucuronic acid catabolism in Salmonella. Int J Med Microbiol 2020; 310:151452. [PMID: 33091748 DOI: 10.1016/j.ijmm.2020.151452] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2020] [Revised: 08/13/2020] [Accepted: 09/25/2020] [Indexed: 11/17/2022] Open
Abstract
Salmonella has evolved various metabolic pathways to scavenge energy from the metabolic byproducts of the host gut microbiota, however, the precise metabolic byproducts and pathways utilized by Salmonella remain elusive. Previously we reported that Salmonella can proliferate by deriving energy from two metabolites that naturally occur in the host as gut microbial metabolic byproducts, namely, tyramine (TYR, an aromatic amine) and d-glucuronic acid (DGA, a hexuronic acid). Salmonella Pathogenicity Island 13 (SPI-13) plays a critical role in the ability of Salmonella to derive energy from TYR and DGA, however the catabolic pathways of these two micronutrients in Salmonella are poorly defined. The objective of this study was to identify the specific genetic components and construct the regulatory circuits for the TYR and DGA catabolic pathways in Salmonella. To accomplish this, we employed TYR and DGA-induced global transcriptional profiling and gene functional network analysis approaches. We report that TYR induced differential expression of 319 genes (172 up-regulated and 157 down-regulated) when Salmonella was grown in the presence of TYR as a sole energy source. These included the genes originally predicted to be involved in the classical TYR catabolic pathway. TYR also induced expression of majority of genes involved in the acetaldehyde degradation pathway and aided identification of a few new genes that are likely involved in alternative pathway for TYR catabolism. In contrast, DGA induced differential expression of 71 genes (58 up-regulated and 13 down-regulated) when Salmonella was grown in the presence of DGA as a sole energy source. These included the genes originally predicted to be involved in the classical pathway and a few new genes likely involved in the alternative pathway for DGA catabolism. Interestingly, DGA also induced expression of SPI-2 T3SS, suggesting that DGA may also influence nutritional virulence of Salmonella. In summary, this is the first report describing the global transcriptional profiling of TYR and DGA catabolic pathways of Salmonella. This study will contribute to the better understanding of the role of TYR and DGA in metabolic adaptation and virulence of Salmonella.
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Affiliation(s)
- Raquel Burin
- Department of Veterinary Microbiology and Pathology, United States
| | - Devendra H Shah
- Department of Veterinary Microbiology and Pathology, United States; Paul Allen School for Global Animal Health, College of Veterinary Medicine, Washington State University, Pullman, WA, 99164-7040, United States.
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19
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Stewart KL, Stewart AM, Bobik TA. Prokaryotic Organelles: Bacterial Microcompartments in E. coli and Salmonella. EcoSal Plus 2020; 9:10.1128/ecosalplus.ESP-0025-2019. [PMID: 33030141 PMCID: PMC7552817 DOI: 10.1128/ecosalplus.esp-0025-2019] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2020] [Indexed: 02/07/2023]
Abstract
Bacterial microcompartments (MCPs) are proteinaceous organelles consisting of a metabolic pathway encapsulated within a selectively permeable protein shell. Hundreds of species of bacteria produce MCPs of at least nine different types, and MCP metabolism is associated with enteric pathogenesis, cancer, and heart disease. This review focuses chiefly on the four types of catabolic MCPs (metabolosomes) found in Escherichia coli and Salmonella: the propanediol utilization (pdu), ethanolamine utilization (eut), choline utilization (cut), and glycyl radical propanediol (grp) MCPs. Although the great majority of work done on catabolic MCPs has been carried out with Salmonella and E. coli, research outside the group is mentioned where necessary for a comprehensive understanding. Salient characteristics found across MCPs are discussed, including enzymatic reactions and shell composition, with particular attention paid to key differences between classes of MCPs. We also highlight relevant research on the dynamic processes of MCP assembly, protein targeting, and the mechanisms that underlie selective permeability. Lastly, we discuss emerging biotechnology applications based on MCP principles and point out challenges, unanswered questions, and future directions.
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Affiliation(s)
- Katie L. Stewart
- The Roy J. Carver Department of Biochemistry, Biophysics and Molecular Biology, Iowa State University, Ames, IA, USA 50011
| | - Andrew M. Stewart
- The Roy J. Carver Department of Biochemistry, Biophysics and Molecular Biology, Iowa State University, Ames, IA, USA 50011
| | - Thomas A. Bobik
- The Roy J. Carver Department of Biochemistry, Biophysics and Molecular Biology, Iowa State University, Ames, IA, USA 50011
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20
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Intracellular Mycobacterium tuberculosis Exploits Multiple Host Nitrogen Sources during Growth in Human Macrophages. Cell Rep 2020; 29:3580-3591.e4. [PMID: 31825837 PMCID: PMC6915324 DOI: 10.1016/j.celrep.2019.11.037] [Citation(s) in RCA: 49] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2019] [Revised: 07/05/2019] [Accepted: 11/07/2019] [Indexed: 02/05/2023] Open
Abstract
Nitrogen metabolism of Mycobacterium tuberculosis (Mtb) is crucial for the survival of this important pathogen in its primary human host cell, the macrophage, but little is known about the source(s) and their assimilation within this intracellular niche. Here, we have developed 15N-flux spectral ratio analysis (15N-FSRA) to explore Mtb’s nitrogen metabolism; we demonstrate that intracellular Mtb has access to multiple amino acids in the macrophage, including glutamate, glutamine, aspartate, alanine, glycine, and valine; and we identify glutamine as the predominant nitrogen donor. Each nitrogen source is uniquely assimilated into specific amino acid pools, indicating compartmentalized metabolism during intracellular growth. We have discovered that serine is not available to intracellular Mtb, and we show that a serine auxotroph is attenuated in macrophages. This work provides a systems-based tool for exploring the nitrogen metabolism of intracellular pathogens and highlights the enzyme phosphoserine transaminase as an attractive target for the development of novel anti-tuberculosis therapies. Mycobacterium tuberculosis utilizes multiple amino acids as nitrogen sources in human macrophages 15N-FSRA tool identified the intracellular nitrogen sources Glutamine is the predominant nitrogen donor for M. tuberculosis Serine biosynthesis is essential for the survival of intracellular M. tuberculosis
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21
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Genetic Characterization of a Glycyl Radical Microcompartment Used for 1,2-Propanediol Fermentation by Uropathogenic Escherichia coli CFT073. J Bacteriol 2020; 202:JB.00017-20. [PMID: 32071097 DOI: 10.1128/jb.00017-20] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2020] [Accepted: 02/13/2020] [Indexed: 12/29/2022] Open
Abstract
Bacterial microcompartments (MCPs) are widespread protein-based organelles composed of metabolic enzymes encapsulated within a protein shell. The function of MCPs is to optimize metabolic pathways by confining toxic and/or volatile pathway intermediates. A major class of MCPs known as glycyl radical MCPs has only been partially characterized. Here, we show that uropathogenic Escherichia coli CFT073 uses a glycyl radical MCP for 1,2-propanediol (1,2-PD) fermentation. Bioinformatic analyses identified a large gene cluster (named grp for glycyl radical propanediol) that encodes homologs of a glycyl radical diol dehydratase, other 1,2-PD catabolic enzymes, and MCP shell proteins. Growth studies showed that E. coli CFT073 grows on 1,2-PD under anaerobic conditions but not under aerobic conditions. All 19 grp genes were individually deleted, and 8/19 were required for 1,2-PD fermentation. Electron microscopy and genetic studies showed that a bacterial MCP is involved. Bioinformatics combined with genetic analyses support a proposed pathway of 1,2-PD degradation and suggest that enzymatic cofactors are recycled internally within the Grp MCP. A two-component system (grpP and grpQ) is shown to mediate induction of the grp locus by 1,2-PD. Tests of the E. coli Reference (ECOR) collection indicate that >10% of E. coli strains ferment 1,2-PD using a glycyl radical MCP. In contrast to other MCP systems, individual deletions of MCP shell genes (grpE, grpH, and grpI) eliminated 1,2-PD catabolism, suggesting significant functional differences with known MCPs. Overall, the studies presented here are the first comprehensive genetic analysis of a Grp-type MCP.IMPORTANCE Bacterial MCPs have a number of potential biotechnology applications and have been linked to bacterial pathogenesis, cancer, and heart disease. Glycyl radical MCPs are a large but understudied class of bacterial MCPs. Here, we show that uropathogenic E. coli CFT073 uses a glycyl radical MCP for 1,2-PD fermentation, and we conduct a comprehensive genetic analysis of the genes involved. Studies suggest significant functional differences between the glycyl radical MCP of E. coli CFT073 and better-studied MCPs. They also provide a foundation for building a deeper general understanding of glycyl radical MCPs in an organism where sophisticated genetic methods are available.
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22
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Apparent size and morphology of bacterial microcompartments varies with technique. PLoS One 2020; 15:e0226395. [PMID: 32150579 PMCID: PMC7062276 DOI: 10.1371/journal.pone.0226395] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2019] [Accepted: 02/25/2020] [Indexed: 12/30/2022] Open
Abstract
Bacterial microcompartments (MCPs) are protein-based organelles that encapsulate metabolic pathways. Metabolic engineers have recently sought to repurpose MCPs to encapsulate heterologous pathways to increase flux through pathways of interest. As MCP engineering becomes more common, standardized methods for analyzing changes to MCPs and interpreting results across studies will become increasingly important. In this study, we demonstrate that different imaging techniques yield variations in the apparent size of purified MCPs from Salmonella enterica serovar Typhimurium LT2, likely due to variations in sample preparation methods. We provide guidelines for preparing samples for MCP imaging and outline expected variations in apparent size and morphology between methods. With this report we aim to establish an aid for comparing results across studies.
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23
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Chowdhury C, Bobik TA. Engineering the PduT shell protein to modify the permeability of the 1,2-propanediol microcompartment of Salmonella. MICROBIOLOGY-SGM 2020; 165:1355-1364. [PMID: 31674899 DOI: 10.1099/mic.0.000872] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
Bacterial microcompartments (MCPs) are protein-based organelles that consist of metabolic enzymes encapsulated within a protein shell. The function of MCPs is to optimize metabolic pathways by increasing reaction rates and sequestering toxic pathway intermediates. A substantial amount of effort has been directed toward engineering synthetic MCPs as intracellular nanoreactors for the improved production of renewable chemicals. A key challenge in this area is engineering protein shells that allow the entry of desired substrates. In this study, we used site-directed mutagenesis of the PduT shell protein to remove its central iron-sulfur cluster and create openings (pores) in the shell of the Pdu MCP that have varied chemical properties. Subsequently, in vivo and in vitro studies were used to show that PduT-C38S and PduT-C38A variants increased the diffusion of 1,2-propanediol, propionaldehyde, NAD+ and NADH across the shell of the MCP. In contrast, PduT-C38I and PduT-C38W eliminated the iron-sulfur cluster without altering the permeability of the Pdu MCP, suggesting that the side-chains of C38I and C38W occluded the opening formed by removal of the iron-sulfur cluster. Thus, genetic modification offers an approach to engineering the movement of larger molecules (such as NAD/H) across MCP shells, as well as a method for blocking transport through trimeric bacterial microcompartment (BMC) domain shell proteins.
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Affiliation(s)
- Chiranjit Chowdhury
- Present address: Amity Institute of Molecular Medicine and Stem Cell Research, Amity University Campus, Sector-125, Noida, UP-201313, India.,Roy J. Carver Department of Biochemistry, Biophysics and Molecular Biology, Iowa State University, Ames, IA, 50011, USA
| | - Thomas A Bobik
- Roy J. Carver Department of Biochemistry, Biophysics and Molecular Biology, Iowa State University, Ames, IA, 50011, USA
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24
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Juodeikis R, Lee MJ, Mayer M, Mantell J, Brown IR, Verkade P, Woolfson DN, Prentice MB, Frank S, Warren MJ. Effect of metabolosome encapsulation peptides on enzyme activity, coaggregation, incorporation, and bacterial microcompartment formation. Microbiologyopen 2020; 9:e1010. [PMID: 32053746 PMCID: PMC7221423 DOI: 10.1002/mbo3.1010] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2019] [Revised: 01/17/2020] [Accepted: 01/21/2020] [Indexed: 01/21/2023] Open
Abstract
Metabolosomes, catabolic bacterial microcompartments (BMCs), are proteinaceous organelles that are associated with the breakdown of metabolites such as propanediol and ethanolamine. They are composed of an outer multicomponent protein shell that encases a specific metabolic pathway. Protein cargo found within BMCs is directed by the presence of an encapsulation peptide that appears to trigger aggregation before the formation of the outer shell. We investigated the effect of three distinct encapsulation peptides on foreign cargo in a recombinant BMC system. Our data demonstrate that these peptides cause variations in enzyme activity and protein aggregation. We observed that the level of protein aggregation generally correlates with the size of metabolosomes, while in the absence of cargo BMCs self‐assemble into smaller compartments. The results agree with a flexible model for BMC formation based around the ability of the BMC shell to associate with an aggregate formed due to the interaction of encapsulation peptides.
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Affiliation(s)
- Rokas Juodeikis
- Centre for Industrial Biotechnology, School of Biosciences, University of Kent, Canterbury, UK
| | - Matthew J Lee
- Centre for Industrial Biotechnology, School of Biosciences, University of Kent, Canterbury, UK
| | - Matthias Mayer
- Centre for Industrial Biotechnology, School of Biosciences, University of Kent, Canterbury, UK
| | - Judith Mantell
- School of Biochemistry, University of Bristol, Bristol, UK.,Wolfson Bioimaging Facility, University of Bristol, Bristol, UK
| | - Ian R Brown
- Centre for Industrial Biotechnology, School of Biosciences, University of Kent, Canterbury, UK
| | - Paul Verkade
- School of Biochemistry, University of Bristol, Bristol, UK.,Wolfson Bioimaging Facility, University of Bristol, Bristol, UK.,BrisSynBio, University of Bristol, Bristol, UK
| | - Derek N Woolfson
- School of Biochemistry, University of Bristol, Bristol, UK.,BrisSynBio, University of Bristol, Bristol, UK.,School of Chemistry, University of Bristol, Bristol, UK
| | | | - Stefanie Frank
- Department of Biochemical Engineering, University College London, London, UK
| | - Martin J Warren
- Centre for Industrial Biotechnology, School of Biosciences, University of Kent, Canterbury, UK
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25
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Plegaria JS, Yates MD, Glaven SM, Kerfeld CA. Redox Characterization of Electrode-Immobilized Bacterial Microcompartment Shell Proteins Engineered To Bind Metal Centers. ACS APPLIED BIO MATERIALS 2019; 3:685-692. [DOI: 10.1021/acsabm.9b01023] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Affiliation(s)
| | - Matthew D. Yates
- Center for Bio/Molecular Science and Engineering, Naval Research Laboratory, Washington, D.C. 20375, United States
| | - Sarah M. Glaven
- Center for Bio/Molecular Science and Engineering, Naval Research Laboratory, Washington, D.C. 20375, United States
| | - Cheryl A. Kerfeld
- Environmental Genomics and Systems Biology and Molecular Biophysics and Integrated Bioimaging Divisions, Lawrence Berkeley National Laboratory, 1 Cyclotron Road, Berkeley, California 94720, United States
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26
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Borchert AJ, Ernst DC, Downs DM. Reactive Enamines and Imines In Vivo: Lessons from the RidA Paradigm. Trends Biochem Sci 2019; 44:849-860. [PMID: 31103411 PMCID: PMC6760865 DOI: 10.1016/j.tibs.2019.04.011] [Citation(s) in RCA: 29] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2019] [Revised: 04/16/2019] [Accepted: 04/17/2019] [Indexed: 01/19/2023]
Abstract
Metabolic networks are webs of integrated reactions organized to maximize growth and replication while minimizing the detrimental impact that reactive metabolites can have on fitness. Enamines and imines, such as 2-aminoacrylate (2AA), are reactive metabolites produced as short-lived intermediates in a number of enzymatic processes. Left unchecked, the inherent reactivity of enamines and imines may perturb the metabolic network. Genetic and biochemical studies have outlined a role for the broadly conserved reactive intermediate deaminase (Rid) (YjgF/YER057c/UK114) protein family, in particular RidA, in catalyzing the hydrolysis of enamines and imines to their ketone product. Herein, we discuss new findings regarding the biological significance of enamine and imine production and outline the importance of RidA in controlling the accumulation of reactive metabolites.
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Affiliation(s)
- Andrew J Borchert
- Department of Microbiology, University of Georgia, Athens, GA 30602, USA
| | - Dustin C Ernst
- Current address: Center for Circadian Biology, University of California, San Diego, San Diego, CA 92161, USA
| | - Diana M Downs
- Department of Microbiology, University of Georgia, Athens, GA 30602, USA.
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Bacterial Microcompartment-Mediated Ethanolamine Metabolism in Escherichia coli Urinary Tract Infection. Infect Immun 2019; 87:IAI.00211-19. [PMID: 31138611 PMCID: PMC6652756 DOI: 10.1128/iai.00211-19] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2019] [Accepted: 05/16/2019] [Indexed: 12/23/2022] Open
Abstract
Urinary tract infections (UTIs) are common and in general are caused by intestinal uropathogenic Escherichia coli (UPEC) ascending via the urethra. Microcompartment-mediated catabolism of ethanolamine, a host cell breakdown product, fuels the competitive overgrowth of intestinal E. coli, both pathogenic enterohemorrhagic E. coli and commensal strains. During a UTI, urease-negative E. coli bacteria thrive, despite the comparative nutrient limitation in urine. Urinary tract infections (UTIs) are common and in general are caused by intestinal uropathogenic Escherichia coli (UPEC) ascending via the urethra. Microcompartment-mediated catabolism of ethanolamine, a host cell breakdown product, fuels the competitive overgrowth of intestinal E. coli, both pathogenic enterohemorrhagic E. coli and commensal strains. During a UTI, urease-negative E. coli bacteria thrive, despite the comparative nutrient limitation in urine. The role of ethanolamine as a potential nutrient source during UTIs is understudied. We evaluated the role of the metabolism of ethanolamine as a potential nitrogen and carbon source for UPEC in the urinary tract. We analyzed infected urine samples by culture, high-performance liquid chromatography, reverse transcription-quantitative PCR, and genomic sequencing. The ethanolamine concentration in urine was comparable to the concentration of the most abundant reported urinary amino acid, d-serine. Transcription of the eut operon was detected in the majority of urine samples containing E. coli screened. All sequenced UPEC strains had conserved eut operons, while metabolic genotypes previously associated with UTI (dsdCXA, metE) were mainly limited to phylogroup B2. In vitro ethanolamine was found to be utilized as a sole source of nitrogen by UPEC strains. The metabolism of ethanolamine in artificial urine medium (AUM) induced metabolosome formation and provided a growth advantage at the physiological levels found in urine. Interestingly, eutE (which encodes acetaldehyde dehydrogenase) was required for UPEC strains to utilize ethanolamine to gain a growth advantage in AUM, suggesting that ethanolamine is also utilized as a carbon source. These data suggest that urinary ethanolamine is a significant additional carbon and nitrogen source for infecting E. coli strains.
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Ferlez B, Sutter M, Kerfeld CA. A designed bacterial microcompartment shell with tunable composition and precision cargo loading. Metab Eng 2019; 54:286-291. [PMID: 31075444 PMCID: PMC6884132 DOI: 10.1016/j.ymben.2019.04.011] [Citation(s) in RCA: 31] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2019] [Revised: 04/09/2019] [Accepted: 04/24/2019] [Indexed: 12/31/2022]
Abstract
Microbes often augment their metabolism by conditionally constructing proteinaceous organelles, known as bacterial microcompartments (BMCs), that encapsulate enzymes to degrade organic compounds or assimilate CO2. BMCs self-assemble and are spatially delimited by a semi-permeable shell made up of hexameric, trimeric, and pentameric shell proteins. Bioengineers aim to recapitulate the organization and efficiency of these complex biological architectures by redesigning the shell to incorporate non-native enzymes from biotechnologically relevant pathways. To meet this challenge, a diverse set of synthetic biology tools are required, including methods to manipulate the properties of the shell as well as target and organize cargo encapsulation. We designed and determined the crystal structure of a synthetic shell protein building block with an inverted sidedness of its N- and C-terminal residues relative to its natural counterpart; the inversion targets genetically fused protein cargo to the lumen of the shell. Moreover, the titer of fluorescent protein cargo encapsulated using this strategy is controllable using an inducible tetracycline promoter. These results expand the available set of building blocks for precision engineering of BMC-based nanoreactors and are compatible with orthogonal methods which will facilitate the installation and organization of multi-enzyme pathways.
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Affiliation(s)
- Bryan Ferlez
- MSU-DOE Plant Research Laboratory, Michigan State University, 612 Wilson Road, East Lansing, MI 48824, USA; Department of Biochemistry and Molecular Biology, Michigan State University, 603 Wilson Road, East Lansing, MI 48824, USA
| | - Markus Sutter
- MSU-DOE Plant Research Laboratory, Michigan State University, 612 Wilson Road, East Lansing, MI 48824, USA; Department of Biochemistry and Molecular Biology, Michigan State University, 603 Wilson Road, East Lansing, MI 48824, USA; Environmental Genomics and Systems Biology and Molecular Biophysics and Integrated Bioimaging Divisions, Lawrence Berkeley National Laboratory, 1 Cyclotron Road, Berkeley, CA 94720, USA
| | - Cheryl A Kerfeld
- MSU-DOE Plant Research Laboratory, Michigan State University, 612 Wilson Road, East Lansing, MI 48824, USA; Department of Biochemistry and Molecular Biology, Michigan State University, 603 Wilson Road, East Lansing, MI 48824, USA; Environmental Genomics and Systems Biology and Molecular Biophysics and Integrated Bioimaging Divisions, Lawrence Berkeley National Laboratory, 1 Cyclotron Road, Berkeley, CA 94720, USA.
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Initial Metabolic Step of a Novel Ethanolamine Utilization Pathway and Its Regulation in Streptomyces coelicolor M145. mBio 2019; 10:mBio.00326-19. [PMID: 31113893 PMCID: PMC6529630 DOI: 10.1128/mbio.00326-19] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023] Open
Abstract
Until now, knowledge of the utilization of ethanolamine in Streptomyces was limited. Our work represents the first attempt to reveal a novel ethanolamine utilization pathway in the actinobacterial model organism S. coelicolor through the characterization of the key enzyme gamma-glutamylethanolamide synthetase GlnA4, which is absolutely required for growth in the presence of ethanolamine. The novel ethanolamine utilization pathway is dissimilar to the currently known ethanolamine utilization pathway, which occurs in metabolome. The novel ethanolamine utilization pathway does not result in the production of toxic by-products (such as acetaldehyde); thus, it is not encapsulated. We believe that this contribution is a milestone in understanding the ecology of Streptomyces and the utilization of alternative nitrogen sources. Our report provides new insight into bacterial primary metabolism, which remains complex and partially unexplored. Streptomyces coelicolor is a Gram-positive soil bacterium with a high metabolic and adaptive potential that is able to utilize a variety of nitrogen sources. However, little is known about the utilization of the alternative nitrogen source ethanolamine. Our study revealed that S. coelicolor can utilize ethanolamine as a sole nitrogen or carbon (N/C) source, although it grows poorly on this nitrogen source due to the absence of a specific ethanolamine permease. Heterologous expression of a putative ethanolamine permease (SPRI_5940) from Streptomycespristinaespiralis positively influenced the biomass accumulation of the overexpression strain grown in defined medium with ethanolamine. In this study, we demonstrated that a glutamine synthetase-like protein, GlnA4 (SCO1613), is involved in the initial metabolic step of a novel ethanolamine utilization pathway in S. coelicolor M145. GlnA4 acts as a gamma-glutamylethanolamide synthetase. Transcriptional analysis revealed that expression of glnA4 was induced by ethanolamine and repressed in the presence of ammonium. Regulation of glnA4 is governed by the transcriptional repressor EpuRI (SCO1614). The ΔglnA4 mutant strain was unable to grow on defined liquid Evans medium supplemented with ethanolamine. High-performance liquid chromatography (HPLC) analysis demonstrated that strain ΔglnA4 is unable to utilize ethanolamine. GlnA4-catalyzed glutamylation of ethanolamine was confirmed in an enzymatic in vitro assay, and the GlnA4 reaction product, gamma-glutamylethanolamide, was detected by HPLC/electrospray ionization-mass spectrometry (HPLC/ESI-MS). In this work, the first step of ethanolamine utilization in S. coelicolor M145 was elucidated, and a putative ethanolamine utilization pathway was deduced based on the sequence similarity and genomic localization of homologous genes.
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Nichols TM, Kennedy NW, Tullman-Ercek D. Cargo encapsulation in bacterial microcompartments: Methods and analysis. Methods Enzymol 2019; 617:155-186. [PMID: 30784401 PMCID: PMC6590060 DOI: 10.1016/bs.mie.2018.12.009] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Metabolic engineers seek to produce high-value products from inexpensive starting materials in a sustainable and cost-effective manner by using microbes as cellular factories. However, pathway development and optimization can be arduous tasks, complicated by pathway bottlenecks and toxicity. Pathway organization has emerged as a potential solution to these issues, and the use of protein- or DNA-based scaffolds has successfully increased the production of several industrially relevant compounds. These efforts demonstrate the usefulness of pathway colocalization and spatial organization for metabolic engineering applications. In particular, scaffolding within an enclosed, subcellular compartment shows great promise for pathway optimization, offering benefits such as increased local enzyme and substrate concentrations, sequestration of toxic or volatile intermediates, and alleviation of cofactor and resource competition with the host. Here, we describe the 1,2-propanediol utilization (Pdu) bacterial microcompartment (MCP) as an enclosed scaffold for pathway sequestration and organization. We first describe methods for controlling Pdu MCP formation, expressing and encapsulating heterologous cargo, and tuning cargo loading levels. We further describe assays for analyzing Pdu MCPs and assessing encapsulation levels. These methods will enable the repurposing of MCPs as tunable nanobioreactors for heterologous pathway encapsulation.
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Affiliation(s)
- Taylor M Nichols
- Department of Chemical and Biological Engineering, Northwestern University, Technological Institute, Evanston, IL, United States
| | - Nolan W Kennedy
- Interdisciplinary Biological Sciences Graduate Program, Northwestern University, Evanston, IL, United States
| | - Danielle Tullman-Ercek
- Department of Chemical and Biological Engineering, Northwestern University, Technological Institute, Evanston, IL, United States; Center for Synthetic Biology, Northwestern University, Technological Institute, Evanston, IL, United States.
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Ferlez B, Sutter M, Kerfeld CA. Glycyl Radical Enzyme-Associated Microcompartments: Redox-Replete Bacterial Organelles. mBio 2019; 10:e02327-18. [PMID: 30622187 PMCID: PMC6325248 DOI: 10.1128/mbio.02327-18] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2018] [Accepted: 11/28/2018] [Indexed: 12/31/2022] Open
Abstract
An increasing number of microbes are being identified that organize catabolic pathways within self-assembling proteinaceous structures known as bacterial microcompartments (BMCs). Most BMCs are characterized by their singular substrate specificity and commonly employ B12-dependent radical mechanisms. In contrast, a less-well-known BMC type utilizes the B12-independent radical chemistry of glycyl radical enzymes (GREs). Unlike B12-dependent enzymes, GREs require an activating enzyme (AE) as well as an external source of electrons to generate an adenosyl radical and form their catalytic glycyl radical. Organisms encoding these glycyl radical enzyme-associated microcompartments (GRMs) confront the challenge of coordinating the activation and maintenance of their GREs with the assembly of a multienzyme core that is encapsulated in a protein shell. The GRMs appear to enlist redox proteins to either generate reductants internally or facilitate the transfer of electrons from the cytosol across the shell. Despite this relative complexity, GRMs are one of the most widespread types of BMC, with distinct subtypes to catabolize different substrates. Moreover, they are encoded by many prominent gut-associated and pathogenic bacteria. In this review, we will focus on the diversity, function, and physiological importance of GRMs, with particular attention given to their associated and enigmatic redox proteins.
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Affiliation(s)
- Bryan Ferlez
- MSU-DOE Plant Research Laboratory, Michigan State University, East Lansing, Michigan, USA
| | - Markus Sutter
- MSU-DOE Plant Research Laboratory, Michigan State University, East Lansing, Michigan, USA
- Environmental Genomics and Systems Biology and Molecular Biophysics and Integrated Bioimaging Divisions, Lawrence Berkeley National Laboratory, Berkeley, California, USA
| | - Cheryl A Kerfeld
- MSU-DOE Plant Research Laboratory, Michigan State University, East Lansing, Michigan, USA
- Department of Biochemistry and Molecular Biology, Michigan State University, East Lansing, Michigan, USA
- Environmental Genomics and Systems Biology and Molecular Biophysics and Integrated Bioimaging Divisions, Lawrence Berkeley National Laboratory, Berkeley, California, USA
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Plegaria JS, Kerfeld CA. Engineering nanoreactors using bacterial microcompartment architectures. Curr Opin Biotechnol 2018; 51:1-7. [PMID: 29035760 PMCID: PMC5899066 DOI: 10.1016/j.copbio.2017.09.005] [Citation(s) in RCA: 27] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2017] [Accepted: 09/19/2017] [Indexed: 12/30/2022]
Abstract
Bacterial microcompartments (BMCs) are organelles that encapsulate enzymes involved in CO2 fixation or carbon catabolism in a selectively permeable protein shell. Here, we highlight recent advances in the bioengineering of these protein-based nanoreactors in heterologous systems, including transfer and expression of BMC gene clusters, the production of template empty shells, and the encapsulation of non-native enzymes.
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Affiliation(s)
- Jefferson S Plegaria
- MSU-DOE Plant Research Laboratory, Michigan State University, East Lansing, MI 48824, USA
| | - Cheryl A Kerfeld
- MSU-DOE Plant Research Laboratory, Michigan State University, East Lansing, MI 48824, USA; Molecular Biophysics and Integrated Bioimaging Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA; Department of Biochemistry & Molecular Biology, Michigan State University, East Lansing, MI 48824, USA; Berkeley Synthetic Biology Institute, Berkeley, CA 94720, USA.
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A Bacterial Microcompartment Is Used for Choline Fermentation by Escherichia coli 536. J Bacteriol 2018; 200:JB.00764-17. [PMID: 29507086 DOI: 10.1128/jb.00764-17] [Citation(s) in RCA: 34] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2017] [Accepted: 02/23/2018] [Indexed: 01/16/2023] Open
Abstract
Bacterial choline degradation in the human gut has been associated with cancer and heart disease. In addition, recent studies found that a bacterial microcompartment is involved in choline utilization by Proteus and Desulfovibrio species. However, many aspects of this process have not been fully defined. Here, we investigate choline degradation by the uropathogen Escherichia coli 536. Growth studies indicated E. coli 536 degrades choline primarily by fermentation. Electron microscopy indicated that a bacterial microcompartment was used for this process. Bioinformatic analyses suggested that the choline utilization (cut) gene cluster of E. coli 536 includes two operons, one containing three genes and a main operon of 13 genes. Regulatory studies indicate that the cutX gene encodes a positive transcriptional regulator required for induction of the main cut operon in response to choline supplementation. Each of the 16 genes in the cut cluster was individually deleted, and phenotypes were examined. The cutX, cutY, cutF, cutO, cutC, cutD, cutU, and cutV genes were required for choline degradation, but the remaining genes of the cut cluster were not essential under the conditions used. The reasons for these varied phenotypes are discussed.IMPORTANCE Here, we investigate choline degradation in E. coli 536. These studies provide a basis for understanding a new type of bacterial microcompartment and may provide deeper insight into the link between choline degradation in the human gut and cancer and heart disease. These are also the first studies of choline degradation in E. coli 536, an organism for which sophisticated genetic analysis methods are available. In addition, the cut gene cluster of E. coli 536 is located in pathogenicity island II (PAI-II536) and hence might contribute to pathogenesis.
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Nawrocki KL, Wetzel D, Jones JB, Woods EC, McBride SM. Ethanolamine is a valuable nutrient source that impacts Clostridium difficile pathogenesis. Environ Microbiol 2018; 20:1419-1435. [PMID: 29349925 PMCID: PMC5903940 DOI: 10.1111/1462-2920.14048] [Citation(s) in RCA: 42] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2017] [Revised: 01/03/2018] [Accepted: 01/14/2018] [Indexed: 12/12/2022]
Abstract
Clostridium (Clostridioides) difficile is a gastrointestinal pathogen that colonizes the intestinal tract of mammals and can cause severe diarrheal disease. Although C. difficile growth is confined to the intestinal tract, our understanding of the specific metabolites and host factors that are important for the growth of the bacterium is limited. In other enteric pathogens, the membrane-derived metabolite, ethanolamine (EA), is utilized as a nutrient source and can function as a signal to initiate the production of virulence factors. In this study, we investigated the effects of ethanolamine and the role of the predicted ethanolamine gene cluster (CD1907-CD1925) on C. difficile growth. Using targeted mutagenesis, we disrupted genes within the eut cluster and assessed their roles in ethanolamine utilization, and the impact of eut disruption on the outcome of infection in a hamster model of disease. Our results indicate that the eut gene cluster is required for the growth of C. difficile on ethanolamine as a primary nutrient source. Further, the inability to utilize ethanolamine resulted in greater virulence and a shorter time to morbidity in the animal model. Overall, these data suggest that ethanolamine is an important nutrient source within the host and that, in contrast to other intestinal pathogens, the metabolism of ethanolamine by C. difficile can delay the onset of disease.
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Affiliation(s)
- Kathryn L. Nawrocki
- Department of Microbiology and Immunology, and Emory Antibiotic Resistance Center, Emory University School of Medicine, Atlanta, GA, USA
| | - Daniela Wetzel
- Department of Microbiology and Immunology, and Emory Antibiotic Resistance Center, Emory University School of Medicine, Atlanta, GA, USA
| | - Joshua B. Jones
- Department of Microbiology and Immunology, and Emory Antibiotic Resistance Center, Emory University School of Medicine, Atlanta, GA, USA
| | - Emily C. Woods
- Department of Microbiology and Immunology, and Emory Antibiotic Resistance Center, Emory University School of Medicine, Atlanta, GA, USA
| | - Shonna M. McBride
- Department of Microbiology and Immunology, and Emory Antibiotic Resistance Center, Emory University School of Medicine, Atlanta, GA, USA
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Abstract
Ethanolamine (EA) is a valuable source of carbon and/or nitrogen for bacteria capable of its catabolism. Because it is derived from the membrane phospholipid phosphatidylethanolamine, it is particularly prevalent in the gastrointestinal tract, which is membrane rich due to turnover of the intestinal epithelium and the resident microbiota. Intriguingly, many gut pathogens carry the eut (ethanolamine utilization) genes. EA utilization has been studied for about 50 years, with most of the early work occurring in just a couple of species of Enterobacteriaceae. Once the metabolic pathways and enzymes were characterized by biochemical approaches, genetic screens were used to map the various activities to the eut genes. With the rise of genomics, the diversity of bacteria containing the eut genes and surprising differences in eut gene content were recognized. Some species contain nearly 20 genes and encode many accessory proteins, while others contain only the core catabolic enzyme. Moreover, the eut genes are regulated by very different mechanisms, depending on the organism and the eut regulator encoded. In the last several years, exciting progress has been made in elucidating the complex regulatory mechanisms that govern eut gene expression. Furthermore, a new appreciation for how EA contributes to infection and colonization in the host is emerging. In addition to providing an overview of EA-related biology, this minireview will give special attention to these recent advances.
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36
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Plegaria JS, Sutter M, Ferlez B, Aussignargues C, Niklas J, Poluektov OG, Fromwiller C, TerAvest M, Utschig LM, Tiede DM, Kerfeld CA. Structural and Functional Characterization of a Short-Chain Flavodoxin Associated with a Noncanonical 1,2-Propanediol Utilization Bacterial Microcompartment. Biochemistry 2017; 56:5679-5690. [PMID: 28956602 DOI: 10.1021/acs.biochem.7b00682] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
Bacterial microcompartments (BMCs) are proteinaceous organelles that encapsulate enzymes involved in CO2 fixation (carboxysomes) or carbon catabolism (metabolosomes). Metabolosomes share a common core of enzymes and a distinct signature enzyme for substrate degradation that defines the function of the BMC (e.g., propanediol or ethanolamine utilization BMCs, or glycyl-radical enzyme microcompartments). Loci encoding metabolosomes also typically contain genes for proteins that support organelle function, such as regulation, transport of substrate, and cofactor (e.g., vitamin B12) synthesis and recycling. Flavoproteins are frequently among these ancillary gene products, suggesting that these redox active proteins play an undetermined function in many metabolosomes. Here, we report the first characterization of a BMC-associated flavodoxin (Fld1C), a small flavoprotein, derived from the noncanonical 1,2-propanediol utilization BMC locus (PDU1C) of Lactobacillus reuteri. The 2.0 Å X-ray structure of Fld1C displays the α/β flavodoxin fold, which noncovalently binds a single flavin mononucleotide molecule. Fld1C is a short-chain flavodoxin with redox potentials of -240 ± 3 mV oxidized/semiquinone and -344 ± 1 mV semiquinone/hydroquinone versus the standard hydrogen electrode at pH 7.5. It can participate in an electron transfer reaction with a photoreductant to form a stable semiquinone species. Collectively, our structural and functional results suggest that PDU1C BMCs encapsulate Fld1C to store and transfer electrons for the reactivation and/or recycling of the B12 cofactor utilized by the signature enzyme.
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Affiliation(s)
- Jefferson S Plegaria
- MSU-DOE Plant Research Laboratory, Michigan State University , East Lansing, Michigan 48824, United States
| | - Markus Sutter
- MSU-DOE Plant Research Laboratory, Michigan State University , East Lansing, Michigan 48824, United States.,Molecular Biophysics and Integrated Bioimaging Division, Lawrence Berkeley National Laboratory , Berkeley, California 94720, United States
| | - Bryan Ferlez
- MSU-DOE Plant Research Laboratory, Michigan State University , East Lansing, Michigan 48824, United States
| | - Clément Aussignargues
- MSU-DOE Plant Research Laboratory, Michigan State University , East Lansing, Michigan 48824, United States
| | - Jens Niklas
- Solar Energy Conversion Group, Argonne National Laboratory , Argonne, Illinois 60439, United States
| | - Oleg G Poluektov
- Solar Energy Conversion Group, Argonne National Laboratory , Argonne, Illinois 60439, United States
| | - Ciara Fromwiller
- MSU-DOE Plant Research Laboratory, Michigan State University , East Lansing, Michigan 48824, United States
| | - Michaela TerAvest
- Department of Biochemistry & Molecular Biology, Michigan State University , East Lansing, Michigan 48824, United States
| | - Lisa M Utschig
- Solar Energy Conversion Group, Argonne National Laboratory , Argonne, Illinois 60439, United States
| | - David M Tiede
- Solar Energy Conversion Group, Argonne National Laboratory , Argonne, Illinois 60439, United States
| | - Cheryl A Kerfeld
- MSU-DOE Plant Research Laboratory, Michigan State University , East Lansing, Michigan 48824, United States.,Molecular Biophysics and Integrated Bioimaging Division, Lawrence Berkeley National Laboratory , Berkeley, California 94720, United States.,Department of Biochemistry & Molecular Biology, Michigan State University , East Lansing, Michigan 48824, United States.,Berkeley Synthetic Biology Institute , Berkeley, California 94720, United States
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Effect of bio-engineering on size, shape, composition and rigidity of bacterial microcompartments. Sci Rep 2016; 6:36899. [PMID: 27845382 PMCID: PMC5109269 DOI: 10.1038/srep36899] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2016] [Accepted: 10/21/2016] [Indexed: 12/17/2022] Open
Abstract
Bacterial microcompartments (BMCs) are proteinaceous organelles that are found in a broad range of bacteria and are composed of an outer shell that encases an enzyme cargo representing a specific metabolic process. The outer shell is made from a number of different proteins that form hexameric and pentameric tiles, which interact to allow the formation of a polyhedral edifice. We have previously shown that the Citrobacter freundii BMC associated with 1,2-propanediol utilization can be transferred into Escherichia coli to generate a recombinant BMC and that empty BMCs can be formed from just the shell proteins alone. Herein, a detailed structural and proteomic characterization of the wild type BMC is compared to the recombinant BMC and a number of empty BMC variants by 2D-gel electrophoresis, mass spectrometry, transmission electron microscopy (TEM) and atomic force microscopy (AFM). Specifically, it is shown that the wild type BMC and the recombinant BMC are similar in terms of composition, size, shape and mechanical properties, whereas the empty BMC variants are shown to be smaller, hollow and less malleable.
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Ethanolamine Catabolism in Pseudomonas aeruginosa PAO1 Is Regulated by the Enhancer-Binding Protein EatR (PA4021) and the Alternative Sigma Factor RpoN. J Bacteriol 2016; 198:2318-29. [PMID: 27325678 DOI: 10.1128/jb.00357-16] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2016] [Accepted: 06/13/2016] [Indexed: 12/31/2022] Open
Abstract
UNLABELLED Although genes encoding enzymes and proteins related to ethanolamine catabolism are widely distributed in the genomes of Pseudomonas spp., ethanolamine catabolism has received little attention among this metabolically versatile group of bacteria. In an attempt to shed light on this subject, this study focused on defining the key regulatory factors that govern the expression of the central ethanolamine catabolic pathway in Pseudomonas aeruginosa PAO1. This pathway is encoded by the PA4022-eat-eutBC operon and consists of a transport protein (Eat), an ethanolamine-ammonia lyase (EutBC), and an acetaldehyde dehydrogenase (PA4022). EutBC is an essential enzyme in ethanolamine catabolism because it hydrolyzes this amino alcohol into ammonia and acetaldehyde. The acetaldehyde intermediate is then converted into acetate in a reaction catalyzed by acetaldehyde dehydrogenase. Using a combination of growth analyses and β-galactosidase fusions, the enhancer-binding protein PA4021 and the sigma factor RpoN were shown to be positive regulators of the PA4022-eat-eutBC operon in P. aeruginosa PAO1. PA4021 and RpoN were required for growth on ethanolamine, and both of these regulatory proteins were essential for induction of the PA4022-eat-eutBC operon. Unexpectedly, the results indicate that acetaldehyde (and not ethanolamine) serves as the inducer molecule that is sensed by PA4021 and leads to the transcriptional activation of the PA4022-eat-eutBC operon. Due to its regulatory role in ethanolamine catabolism, PA4021 was given the name EatR. Both EatR and its target genes are conserved in several other Pseudomonas spp., suggesting that these bacteria share a mechanism for regulating ethanolamine catabolism. IMPORTANCE The results of this study provide a basis for understanding ethanolamine catabolism and its regulation in Pseudomonas aeruginosa PAO1. Interestingly, expression of the ethanolamine-catabolic genes in this bacterium was found to be under the control of a positive-feedback regulatory loop in a manner dependent on the transcriptional regulator PA4021, the sigma factor RpoN, and the metabolite acetaldehyde. Previously characterized regulators of ethanolamine catabolism are known to sense and respond directly to ethanolamine. In contrast, PA4021 (EatR) appears to monitor the intracellular levels of free acetaldehyde and responds through transcriptional activation of the ethanolamine-catabolic genes. This regulatory mechanism is unique and represents an alternative strategy used by bacteria to govern the acquisition of ethanolamine from their surroundings.
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Held M, Kolb A, Perdue S, Hsu SY, Bloch SE, Quin MB, Schmidt-Dannert C. Engineering formation of multiple recombinant Eut protein nanocompartments in E. coli. Sci Rep 2016; 6:24359. [PMID: 27063436 PMCID: PMC4827028 DOI: 10.1038/srep24359] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2015] [Accepted: 03/29/2016] [Indexed: 01/17/2023] Open
Abstract
Compartmentalization of designed metabolic pathways within protein based nanocompartments has the potential to increase reaction efficiency in multi-step biosynthetic reactions. We previously demonstrated proof-of-concept of this aim by targeting a functional enzyme to single cellular protein nanocompartments, which were formed upon recombinant expression of the Salmonella enterica LT2 ethanolamine utilization bacterial microcompartment shell proteins EutS or EutSMNLK in Escherichia coli. To optimize this system, increasing overall encapsulated enzyme reaction efficiency, factor(s) required for the production of more than one nanocompartment per cell must be identified. In this work we report that the cupin domain protein EutQ is required for assembly of more than one nanocompartment per cell. Overexpression of EutQ results in multiple nanocompartment assembly in our recombinant system. EutQ specifically interacts with the shell protein EutM in vitro via electrostatic interactions with the putative cytosolic face of EutM. These findings lead to the theory that EutQ could facilitate multiple nanocompartment biogenesis by serving as an assembly hub for shell proteins. This work offers insights into the biogenesis of Eut bacterial microcompartments, and also provides an improved platform for the production of protein based nanocompartments for targeted encapsulation of enzyme pathways.
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Affiliation(s)
- Mark Held
- Department of Biochemistry, Molecular Biology and Biophysics, University of Minnesota, St. Paul, MN 55108, USA
| | - Alexander Kolb
- Department of Biochemistry, Molecular Biology and Biophysics, University of Minnesota, St. Paul, MN 55108, USA
| | - Sarah Perdue
- Department of Biochemistry, Molecular Biology and Biophysics, University of Minnesota, St. Paul, MN 55108, USA
| | - Szu-Yi Hsu
- Department of Biochemistry, Molecular Biology and Biophysics, University of Minnesota, St. Paul, MN 55108, USA
| | - Sarah E Bloch
- Department of Biochemistry, Molecular Biology and Biophysics, University of Minnesota, St. Paul, MN 55108, USA
| | - Maureen B Quin
- Department of Biochemistry, Molecular Biology and Biophysics, University of Minnesota, St. Paul, MN 55108, USA
| | - Claudia Schmidt-Dannert
- Department of Biochemistry, Molecular Biology and Biophysics, University of Minnesota, St. Paul, MN 55108, USA
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Lee MJ, Brown IR, Juodeikis R, Frank S, Warren MJ. Employing bacterial microcompartment technology to engineer a shell-free enzyme-aggregate for enhanced 1,2-propanediol production in Escherichia coli. Metab Eng 2016; 36:48-56. [PMID: 26969252 PMCID: PMC4909751 DOI: 10.1016/j.ymben.2016.02.007] [Citation(s) in RCA: 67] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2015] [Revised: 02/05/2016] [Accepted: 02/22/2016] [Indexed: 01/01/2023]
Abstract
Bacterial microcompartments (BMCs) enhance the breakdown of metabolites such as 1,2-propanediol (1,2-PD) to propionic acid. The encapsulation of proteins within the BMC is mediated by the presence of targeting sequences. In an attempt to redesign the Pdu BMC into a 1,2-PD synthesising factory using glycerol as the starting material we added N-terminal targeting peptides to glycerol dehydrogenase, dihydroxyacetone kinase, methylglyoxal synthase and 1,2-propanediol oxidoreductase to allow their inclusion into an empty BMC. 1,2-PD producing strains containing the fused enzymes exhibit a 245% increase in product formation in comparison to un-tagged enzymes, irrespective of the presence of BMCs. Tagging of enzymes with targeting peptides results in the formation of dense protein aggregates within the cell that are shown by immuno-labelling to contain the vast majority of tagged proteins. It can therefore be concluded that these protein inclusions are metabolically active and facilitate the significant increase in product formation. Fusion of BMC targeting peptides to enzymes has a variable effect on activity. Tagged enzymes for 1,2-propanediol synthesis are localised to a BMC. BMC-targeted proteins localised within the BMC are protected from proteases. TEM reveals tagged enzymes form large intracellular protein aggregates. Strains with enzyme aggregates are shown to have enhanced 1,2-propanediol production.
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Affiliation(s)
- Matthew J Lee
- School of Biosciences, University of Kent, Giles Lane, Canterbury, Kent CT2 7NJ, UK
| | - Ian R Brown
- School of Biosciences, University of Kent, Giles Lane, Canterbury, Kent CT2 7NJ, UK
| | - Rokas Juodeikis
- School of Biosciences, University of Kent, Giles Lane, Canterbury, Kent CT2 7NJ, UK
| | - Stefanie Frank
- School of Biosciences, University of Kent, Giles Lane, Canterbury, Kent CT2 7NJ, UK.
| | - Martin J Warren
- School of Biosciences, University of Kent, Giles Lane, Canterbury, Kent CT2 7NJ, UK.
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Moore TC, Escalante-Semerena JC. The EutQ and EutP proteins are novel acetate kinases involved in ethanolamine catabolism: physiological implications for the function of the ethanolamine metabolosome in Salmonella enterica. Mol Microbiol 2015; 99:497-511. [PMID: 26448059 DOI: 10.1111/mmi.13243] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/05/2015] [Indexed: 11/29/2022]
Abstract
Salmonella enterica catabolizes ethanolamine inside a compartment known as the metabolosome. The ethanolamine utilization (eut) operon of this bacterium encodes all functions needed for the assembly and function of this structure. To date, the roles of EutQ and EutP were not known. Herein we show that both proteins have acetate kinase activity and that EutQ is required during anoxic growth of S. enterica on ethanolamine and tetrathionate. EutP and EutQ-dependent ATP synthesis occurred when enzymes were incubated with ADP, Mg(II) ions and acetyl-phosphate. EutQ and EutP also synthesized acetyl-phosphate from ATP and acetate. Although EutP had acetate kinase activity, ΔeutP strains lacked discernible phenotypes under the conditions where ΔeutQ strains displayed clear phenotypes. The kinetic parameters indicate that EutP is a faster enzyme than EutQ. Our evidence supports the conclusion that EutQ and EutP represent novel classes of acetate kinases. We propose that EutQ is necessary to drive flux through the pathway under physiological conditions, preventing a buildup of acetaldehyde. We also suggest that ATP generated by these enzymes may be used as a substrate for EutT, the ATP-dependent corrinoid adenosyltransferase and for the EutA ethanolamine ammonia-lyase reactivase.
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Affiliation(s)
- Theodore C Moore
- Department of Microbiology, University of Georgia, 120 Cedar Street, Athens, GA, 30602, USA
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Abstract
This review summarizes research performed over the last 23 years on the genetics, enzyme structures and functions, and regulation of the expression of the genes encoding functions involved in adenosylcobalamin (AdoCbl, or coenzyme B12) biosynthesis. It also discusses the role of coenzyme B12 in the physiology of Salmonella enterica serovar Typhimurium LT2 and Escherichia coli. John Roth's seminal contributions to the field of coenzyme B12 biosynthesis research brought the power of classical and molecular genetic, biochemical, and structural approaches to bear on the extremely challenging problem of dissecting the steps of what has turned out to be one of the most complex biosynthetic pathways known. In E. coli and serovar Typhimurium, uro'gen III represents the first branch point in the pathway, where the routes for cobalamin and siroheme synthesis diverge from that for heme synthesis. The cobalamin biosynthetic pathway in P. denitrificans was the first to be elucidated, but it was soon realized that there are at least two routes for cobalamin biosynthesis, representing aerobic and anaerobic variations. The expression of the AdoCbl biosynthetic operon is complex and is modulated at different levels. At the transcriptional level, a sensor response regulator protein activates the transcription of the operon in response to 1,2-Pdl in the environment. Serovar Typhimurium and E. coli use ethanolamine as a source of carbon, nitrogen, and energy. In addition, and unlike E. coli, serovar Typhimurium can also grow on 1,2-Pdl as the sole source of carbon and energy.
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Bobik TA, Lehman BP, Yeates TO. Bacterial microcompartments: widespread prokaryotic organelles for isolation and optimization of metabolic pathways. Mol Microbiol 2015; 98:193-207. [PMID: 26148529 PMCID: PMC4718714 DOI: 10.1111/mmi.13117] [Citation(s) in RCA: 99] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/03/2015] [Indexed: 12/15/2022]
Abstract
Prokaryotes use subcellular compartments for a variety of purposes. An intriguing example is a family of complex subcellular organelles known as bacterial microcompartments (MCPs). MCPs are widely distributed among bacteria and impact processes ranging from global carbon fixation to enteric pathogenesis. Overall, MCPs consist of metabolic enzymes encased within a protein shell, and their function is to optimize biochemical pathways by confining toxic or volatile metabolic intermediates. MCPs are fundamentally different from other organelles in having a complex protein shell rather than a lipid-based membrane as an outer barrier. This unusual feature raises basic questions about organelle assembly, protein targeting and metabolite transport. In this review, we discuss the three best-studied MCPs highlighting atomic-level models for shell assembly, targeting sequences that direct enzyme encapsulation, multivalent proteins that organize the lumen enzymes, the principles of metabolite movement across the shell, internal cofactor recycling, a potential system of allosteric regulation of metabolite transport and the mechanism and rationale behind the functional diversification of the proteins that form the shell. We also touch on some potential biotechnology applications of an unusual compartment designed by nature to optimize metabolic processes within a cellular context.
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Affiliation(s)
- Thomas A. Bobik
- Roy J. Carver Department of Biochemistry, Biophysics and Molecular Biology, Iowa State University, Ames, IA, 50011
| | - Brent P. Lehman
- Roy J. Carver Department of Biochemistry, Biophysics and Molecular Biology, Iowa State University, Ames, IA, 50011
| | - Todd O. Yeates
- Molecular Biology Institute, University of California, Los Angeles
- UCLA-DOE Institute for Genomics and Proteomics, University of California, Los Angeles
- Department of Chemistry and Biochemistry, University of California, Los Angeles
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44
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Bioinformatic characterization of glycyl radical enzyme-associated bacterial microcompartments. Appl Environ Microbiol 2015; 81:8315-29. [PMID: 26407889 DOI: 10.1128/aem.02587-15] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2015] [Accepted: 09/18/2015] [Indexed: 12/26/2022] Open
Abstract
Bacterial microcompartments (BMCs) are proteinaceous organelles encapsulating enzymes that catalyze sequential reactions of metabolic pathways. BMCs are phylogenetically widespread; however, only a few BMCs have been experimentally characterized. Among them are the carboxysomes and the propanediol- and ethanolamine-utilizing microcompartments, which play diverse metabolic and ecological roles. The substrate of a BMC is defined by its signature enzyme. In catabolic BMCs, this enzyme typically generates an aldehyde. Recently, it was shown that the most prevalent signature enzymes encoded by BMC loci are glycyl radical enzymes, yet little is known about the function of these BMCs. Here we characterize the glycyl radical enzyme-associated microcompartment (GRM) loci using a combination of bioinformatic analyses and active-site and structural modeling to show that the GRMs comprise five subtypes. We predict distinct functions for the GRMs, including the degradation of choline, propanediol, and fuculose phosphate. This is the first family of BMCs for which identification of the signature enzyme is insufficient for predicting function. The distinct GRM functions are also reflected in differences in shell composition and apparently different assembly pathways. The GRMs are the counterparts of the vitamin B12-dependent propanediol- and ethanolamine-utilizing BMCs, which are frequently associated with virulence. This study provides a comprehensive foundation for experimental investigations of the diverse roles of GRMs. Understanding this plasticity of function within a single BMC family, including characterization of differences in permeability and assembly, can inform approaches to BMC bioengineering and the design of therapeutics.
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Aussignargues C, Paasch BC, Gonzalez-Esquer R, Erbilgin O, Kerfeld CA. Bacterial microcompartment assembly: The key role of encapsulation peptides. Commun Integr Biol 2015; 8:e1039755. [PMID: 26478774 PMCID: PMC4594438 DOI: 10.1080/19420889.2015.1039755] [Citation(s) in RCA: 51] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2015] [Revised: 04/03/2015] [Accepted: 04/06/2015] [Indexed: 12/14/2022] Open
Abstract
Bacterial microcompartments (BMCs) are proteinaceous organelles used by a broad range of bacteria to segregate and optimize metabolic reactions. Their functions are diverse, and can be divided into anabolic (carboxysome) and catabolic (metabolosomes) processes, depending on their cargo enzymes. The assembly pathway for the β-carboxysome has been characterized, revealing that biogenesis proceeds from the inside out. The enzymes coalesce into a procarboxysome, followed by encapsulation in a protein shell that is recruited to the procarboxysome by a short (∼17 amino acids) extension on the C-terminus of one of the encapsulated proteins. A similar extension is also found on the N- or C-termini of a subset of metabolosome core enzymes. These encapsulation peptides (EPs) are characterized by a primary structure predicted to form an amphipathic α-helix that interacts with shell proteins. Here, we review the features, function and widespread occurrence of EPs among metabolosomes, and propose an expanded role for EPs in the assembly of diverse BMCs.
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Affiliation(s)
| | - Bradley C Paasch
- DOE Plant Research Laboratory; Michigan State University ; East Lansing, MI USA
| | | | - Onur Erbilgin
- Department of Plant and Microbial Biology; University of California, Berkeley ; Berkeley, CA USA
| | - Cheryl A Kerfeld
- DOE Plant Research Laboratory; Michigan State University ; East Lansing, MI USA ; Department of Plant and Microbial Biology; University of California, Berkeley ; Berkeley, CA USA ; Physical Biosciences Division; Lawrence Berkeley National Laboratory ; Berkeley, CA USA ; Berkeley Synthetic Biology Institute ; Berkeley, CA USA
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Abstract
Bacterial microcompartments (MCPs) are sophisticated protein-based organelles used to optimize metabolic pathways. They consist of metabolic enzymes encapsulated within a protein shell, which creates an ideal environment for catalysis and facilitates the channeling of toxic/volatile intermediates to downstream enzymes. The metabolic processes that require MCPs are diverse and widely distributed and play important roles in global carbon fixation and bacterial pathogenesis. The protein shells of MCPs are thought to selectively control the movement of enzyme cofactors, substrates, and products (including toxic or volatile intermediates) between the MCP interior and the cytoplasm of the cell using both passive electrostatic/steric and dynamic gated mechanisms. Evidence suggests that specialized shell proteins conduct electrons between the cytoplasm and the lumen of the MCP and/or help rebuild damaged iron-sulfur centers in the encapsulated enzymes. The MCP shell is elaborated through a family of small proteins whose structural core is known as a bacterial microcompartment (BMC) domain. BMC domain proteins oligomerize into flat, hexagonally shaped tiles, which assemble into extended protein sheets that form the facets of the shell. Shape complementarity along the edges allows different types of BMC domain proteins to form mixed sheets, while sequence variation provides functional diversification. Recent studies have also revealed targeting sequences that mediate protein encapsulation within MCPs, scaffolding proteins that organize lumen enzymes and the use of private cofactor pools (NAD/H and coenzyme A [HS-CoA]) to facilitate cofactor homeostasis. Although much remains to be learned, our growing understanding of MCPs is providing a basis for bioengineering of protein-based containers for the production of chemicals/pharmaceuticals and for use as molecular delivery vehicles.
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Selective molecular transport through the protein shell of a bacterial microcompartment organelle. Proc Natl Acad Sci U S A 2015; 112:2990-5. [PMID: 25713376 DOI: 10.1073/pnas.1423672112] [Citation(s) in RCA: 105] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Bacterial microcompartments are widespread prokaryotic organelles that have important and diverse roles ranging from carbon fixation to enteric pathogenesis. Current models for microcompartment function propose that their outer protein shell is selectively permeable to small molecules, but whether a protein shell can mediate selective permeability and how this occurs are unresolved questions. Here, biochemical and physiological studies of structure-guided mutants are used to show that the hexameric PduA shell protein of the 1,2-propanediol utilization (Pdu) microcompartment forms a selectively permeable pore tailored for the influx of 1,2-propanediol (the substrate of the Pdu microcompartment) while restricting the efflux of propionaldehyde, a toxic intermediate of 1,2-propanediol catabolism. Crystal structures of various PduA mutants provide a foundation for interpreting the observed biochemical and phenotypic data in terms of molecular diffusion across the shell. Overall, these studies provide a basis for understanding a class of selectively permeable channels formed by nonmembrane proteins.
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Axen SD, Erbilgin O, Kerfeld CA. A taxonomy of bacterial microcompartment loci constructed by a novel scoring method. PLoS Comput Biol 2014; 10:e1003898. [PMID: 25340524 PMCID: PMC4207490 DOI: 10.1371/journal.pcbi.1003898] [Citation(s) in RCA: 171] [Impact Index Per Article: 17.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2014] [Accepted: 09/09/2014] [Indexed: 01/21/2023] Open
Abstract
Bacterial microcompartments (BMCs) are proteinaceous organelles involved in both autotrophic and heterotrophic metabolism. All BMCs share homologous shell proteins but differ in their complement of enzymes; these are typically encoded adjacent to shell protein genes in genetic loci, or operons. To enable the identification and prediction of functional (sub)types of BMCs, we developed LoClass, an algorithm that finds putative BMC loci and inventories, weights, and compares their constituent pfam domains to construct a locus similarity network and predict locus (sub)types. In addition to using LoClass to analyze sequences in the Non-redundant Protein Database, we compared predicted BMC loci found in seven candidate bacterial phyla (six from single-cell genomic studies) to the LoClass taxonomy. Together, these analyses resulted in the identification of 23 different types of BMCs encoded in 30 distinct locus (sub)types found in 23 bacterial phyla. These include the two carboxysome types and a divergent set of metabolosomes, BMCs that share a common catalytic core and process distinct substrates via specific signature enzymes. Furthermore, many Candidate BMCs were found that lack one or more core metabolosome components, including one that is predicted to represent an entirely new paradigm for BMC-associated metabolism, joining the carboxysome and metabolosome. By placing these results in a phylogenetic context, we provide a framework for understanding the horizontal transfer of these loci, a starting point for studies aimed at understanding the evolution of BMCs. This comprehensive taxonomy of BMC loci, based on their constituent protein domains, foregrounds the functional diversity of BMCs and provides a reference for interpreting the role of BMC gene clusters encoded in isolate, single cell, and metagenomic data. Many loci encode ancillary functions such as transporters or genes for cofactor assembly; this expanded vocabulary of BMC-related functions should be useful for design of genetic modules for introducing BMCs in bioengineering applications. Some enzymatic transformations have undesirable side reactions, produce toxic or volatile intermediates, or are inefficient; these shortcomings can be alleviated through their sequestration with their substrates in a confined space, as in the membrane-bound organelles of eukaryotes. Recently, it was discovered that bacteria also form organelles–bacterial microcompartments (BMCs)–composed of a protein shell that surrounds functionally related enzymes. BMCs long evaded detection because they typically form only in the presence of the substrate they metabolize, and they can only be visualized by electron microscopy. A few BMCs have been experimentally characterized; they have diverse functions in CO2 fixation, pathogenesis, and niche colonization. While the encapsulated enzymes differ among functionally distinct BMCs, the shell architecture is conserved. This enables their detection computationally, as genes for shell proteins are typically nearby genes for the encapsulated enzymes. We developed a novel algorithm to comprehensively identify and categorize BMCs in sequenced bacterial genomes. We show that BMCs are often encoded adjacent to genes that play supporting roles to the organelle's function. Our results provide the first glimpse of the extent of BMC metabolic diversity and will inform design of genetic modules encoding BMCs for introduction of new metabolic functions in a plug-and-play approach.
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Affiliation(s)
- Seth D. Axen
- DOE Joint Genome Institute, Walnut Creek, California, United States of America
| | - Onur Erbilgin
- Department of Plant and Microbial Biology, University of California, Berkeley, Berkeley, California, United States of America
| | - Cheryl A. Kerfeld
- Department of Plant and Microbial Biology, University of California, Berkeley, Berkeley, California, United States of America
- DOE Plant Research Laboratory, Michigan State University, East Lansing, Michigan, United States of America
- Physical Biosciences Division, Lawrence Berkeley National Laboratory, Berkeley, California, United States of America
- Berkeley Synthetic Biology Institute, Berkeley, California, United States of America
- * E-mail: ,
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De Angelis M, Bottacini F, Fosso B, Kelleher P, Calasso M, Di Cagno R, Ventura M, Picardi E, van Sinderen D, Gobbetti M. Lactobacillus rossiae, a vitamin B12 producer, represents a metabolically versatile species within the Genus Lactobacillus. PLoS One 2014; 9:e107232. [PMID: 25264826 PMCID: PMC4180280 DOI: 10.1371/journal.pone.0107232] [Citation(s) in RCA: 57] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2014] [Accepted: 08/06/2014] [Indexed: 01/21/2023] Open
Abstract
Lactobacillus rossiae is an obligately hetero-fermentative lactic acid bacterium, which can be isolated from a broad range of environments including sourdoughs, vegetables, fermented meat and flour, as well as the gastrointestinal tract of both humans and animals. In order to unravel distinctive genomic features of this particular species and investigate the phylogenetic positioning within the genus Lactobacillus, comparative genomics and phylogenomic approaches, followed by functional analyses were performed on L. rossiae DSM 15814T, showing how this type strain not only occupies an independent phylogenetic branch, but also possesses genomic features underscoring its biotechnological potential. This strain in fact represents one of a small number of bacteria known to encode a complete de novo biosynthetic pathway of vitamin B12 (in addition to other B vitamins such as folate and riboflavin). In addition, it possesses the capacity to utilize an extensive set of carbon sources, a characteristic that may contribute to environmental adaptation, perhaps enabling the strain's ability to populate different niches.
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Affiliation(s)
- Maria De Angelis
- Department of Soil, Plant and Food Sciences, University of Bari Aldo Moro, Bari, Italy
| | | | - Bruno Fosso
- Department of Bioscience, Biotechnology and Biopharmaceutical, University of Bari Aldo Moro, Bari, Italy
| | - Philip Kelleher
- Department of Microbiology, University College Cork, Cork, Ireland
| | - Maria Calasso
- Department of Soil, Plant and Food Sciences, University of Bari Aldo Moro, Bari, Italy
| | - Raffaella Di Cagno
- Department of Soil, Plant and Food Sciences, University of Bari Aldo Moro, Bari, Italy
| | - Marco Ventura
- Laboratory of Probiogenomics, Department of Life Sciences, University of Parma, Parma, Italy
| | - Ernesto Picardi
- Department of Bioscience, Biotechnology and Biopharmaceutical, University of Bari Aldo Moro, Bari, Italy; Institute of Biomembranes and Bioenergetics (IBBE), CNR, Bari, Italy; National Institute of Biostructures and Biosystems (INBB), Rome, Italy
| | - Douwe van Sinderen
- Department of Microbiology, University College Cork, Cork, Ireland; Alimentary Pharmabiotic Centre, University College Cork, Cork, Ireland
| | - Marco Gobbetti
- Department of Soil, Plant and Food Sciences, University of Bari Aldo Moro, Bari, Italy
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50
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Chowdhury C, Sinha S, Chun S, Yeates TO, Bobik TA. Diverse bacterial microcompartment organelles. Microbiol Mol Biol Rev 2014. [PMID: 25184561 DOI: 10.1128/mmbr.00009–14] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/17/2023] Open
Abstract
Bacterial microcompartments (MCPs) are sophisticated protein-based organelles used to optimize metabolic pathways. They consist of metabolic enzymes encapsulated within a protein shell, which creates an ideal environment for catalysis and facilitates the channeling of toxic/volatile intermediates to downstream enzymes. The metabolic processes that require MCPs are diverse and widely distributed and play important roles in global carbon fixation and bacterial pathogenesis. The protein shells of MCPs are thought to selectively control the movement of enzyme cofactors, substrates, and products (including toxic or volatile intermediates) between the MCP interior and the cytoplasm of the cell using both passive electrostatic/steric and dynamic gated mechanisms. Evidence suggests that specialized shell proteins conduct electrons between the cytoplasm and the lumen of the MCP and/or help rebuild damaged iron-sulfur centers in the encapsulated enzymes. The MCP shell is elaborated through a family of small proteins whose structural core is known as a bacterial microcompartment (BMC) domain. BMC domain proteins oligomerize into flat, hexagonally shaped tiles, which assemble into extended protein sheets that form the facets of the shell. Shape complementarity along the edges allows different types of BMC domain proteins to form mixed sheets, while sequence variation provides functional diversification. Recent studies have also revealed targeting sequences that mediate protein encapsulation within MCPs, scaffolding proteins that organize lumen enzymes and the use of private cofactor pools (NAD/H and coenzyme A [HS-CoA]) to facilitate cofactor homeostasis. Although much remains to be learned, our growing understanding of MCPs is providing a basis for bioengineering of protein-based containers for the production of chemicals/pharmaceuticals and for use as molecular delivery vehicles.
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Affiliation(s)
- Chiranjit Chowdhury
- Roy J. Carver Department of Biochemistry, Biophysics and Molecular Biology, Iowa State University, Ames, Iowa, USA
| | - Sharmistha Sinha
- Roy J. Carver Department of Biochemistry, Biophysics and Molecular Biology, Iowa State University, Ames, Iowa, USA
| | - Sunny Chun
- Molecular Biology Institute, University of California, Los Angeles, Los Angeles, California, USA
| | - Todd O Yeates
- Molecular Biology Institute, University of California, Los Angeles, Los Angeles, California, USA Department of Energy Institute for Genomics and Proteomics, University of California, Los Angeles, Los Angeles, California, USA Department of Chemistry and Biochemistry, University of California, Los Angeles, Los Angeles, California, USA
| | - Thomas A Bobik
- Roy J. Carver Department of Biochemistry, Biophysics and Molecular Biology, Iowa State University, Ames, Iowa, USA
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