1
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Shang Y, Guo W, Liu X, Ma L, Liu D, Chen S. Co-expression of nitrogenase proteins in cotton (Gossypium hirsutum L.). PLoS One 2023; 18:e0290556. [PMID: 37616286 PMCID: PMC10449186 DOI: 10.1371/journal.pone.0290556] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2023] [Accepted: 08/09/2023] [Indexed: 08/26/2023] Open
Abstract
Chemical nitrogen fertilizer can maintain crop productivity, but overuse of chemical nitrogen fertilizers leads to economic costs and environmental pollution. One approach to reduce use of nitrogen fertilizers is to transfer nitrogenase biosynthetic pathway to non-legume plants. Fe protein encoded by nifH and MoFe protein encoded by nifD and nifK are two structural components of nitrogenase. NifB encoded by nifB is a critical maturase that catalyzes the first committed step in the biosynthesis of nitrogenase FeMo-cofactor that binds and reduces N2. Expression of the nifB, nifH, nifD and nifK is essential to generate plants that are able to fix atmospheric N2. In this study, the four genes (nifB, nifH, nifD and nifK) from Paenibacillu polymyxaWLY78 were assembled in plant expression vector pCAMBIA1301 via Cre/LoxP recombination system, yielding the recombinant expression vector pCAMBIA1301-nifBHDK. Then, the four nif genes carried in the expression vector were co-introduced into upland cotton R15 using Agrobacterium tumefaciens-mediated transformation. Homozygous transgenic cotton lines B2, B5 and B17 of T3 generation were selected by PCR and RT-PCR. qRT-PCR showed that nifB, nifH, nifD and nifK were co-expressed in the transgenic cottons at similar levels. Western blotting analysis demonstrated that NifB, NifH, NifD and NifK were co-produced in the transgenic cottons. Co-expression of the four critical Nif proteins (NifB, NifH, NifD and NifK) in cottons represents an important step in engineering nitrogenase biosynthetic pathway to non-legume plants.
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Affiliation(s)
- Yimin Shang
- College of Biological Sciences, China Agricultural University, Beijing, China
| | - Wenfang Guo
- Biotechnology Research Institute, Chinese Academy of Agricultural Sciences, Beijing, China
| | - Xiaomeng Liu
- College of Biological Sciences, China Agricultural University, Beijing, China
| | - Lei Ma
- College of Biological Sciences, China Agricultural University, Beijing, China
| | - Dehu Liu
- Biotechnology Research Institute, Chinese Academy of Agricultural Sciences, Beijing, China
| | - Sanfeng Chen
- College of Biological Sciences, China Agricultural University, Beijing, China
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2
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Martin Del Campo JS, Rigsbee J, Bueno Batista M, Mus F, Rubio LM, Einsle O, Peters JW, Dixon R, Dean DR, Dos Santos PC. Overview of physiological, biochemical, and regulatory aspects of nitrogen fixation in Azotobacter vinelandii. Crit Rev Biochem Mol Biol 2023; 57:492-538. [PMID: 36877487 DOI: 10.1080/10409238.2023.2181309] [Citation(s) in RCA: 12] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/07/2023]
Abstract
Understanding how Nature accomplishes the reduction of inert nitrogen gas to form metabolically tractable ammonia at ambient temperature and pressure has challenged scientists for more than a century. Such an understanding is a key aspect toward accomplishing the transfer of the genetic determinants of biological nitrogen fixation to crop plants as well as for the development of improved synthetic catalysts based on the biological mechanism. Over the past 30 years, the free-living nitrogen-fixing bacterium Azotobacter vinelandii emerged as a preferred model organism for mechanistic, structural, genetic, and physiological studies aimed at understanding biological nitrogen fixation. This review provides a contemporary overview of these studies and places them within the context of their historical development.
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Affiliation(s)
| | - Jack Rigsbee
- Department of Chemistry, Wake Forest University, Winston-Salem, NC, USA
| | | | - Florence Mus
- Institute of Biological Chemistry, Washington State University, Pullman, WA, USA
| | - Luis M Rubio
- Centro de Biotecnología y Genómica de Plantas, Universidad Politécnica de Madrid (UPM) - Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria (INIA/CSIC), Pozuelo de Alarcón, Spain
| | - Oliver Einsle
- Department of Biochemistry, University of Freiburg, Freiburg, Germany
| | - John W Peters
- Institute of Biological Chemistry, Washington State University, Pullman, WA, USA
| | - Ray Dixon
- Department of Molecular Microbiology, John Innes Centre, Norwich, UK
| | - Dennis R Dean
- Department of Biochemistry, Virginia Tech, Blacksburg, VA, USA
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3
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Biełło KA, Lucena C, López-Tenllado FJ, Hidalgo-Carrillo J, Rodríguez-Caballero G, Cabello P, Sáez LP, Luque-Almagro V, Roldán MD, Moreno-Vivián C, Olaya-Abril A. Holistic view of biological nitrogen fixation and phosphorus mobilization in Azotobacter chroococcum NCIMB 8003. Front Microbiol 2023; 14:1129721. [PMID: 36846808 PMCID: PMC9945222 DOI: 10.3389/fmicb.2023.1129721] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2022] [Accepted: 01/23/2023] [Indexed: 02/11/2023] Open
Abstract
Nitrogen (N) and phosphorus (P) deficiencies are two of the most agronomic problems that cause significant decrease in crop yield and quality. N and P chemical fertilizers are widely used in current agriculture, causing environmental problems and increasing production costs. Therefore, the development of alternative strategies to reduce the use of chemical fertilizers while maintaining N and P inputs are being investigated. Although dinitrogen is an abundant gas in the atmosphere, it requires biological nitrogen fixation (BNF) to be transformed into ammonium, a nitrogen source assimilable by living organisms. This process is bioenergetically expensive and, therefore, highly regulated. Factors like availability of other essential elements, as phosphorus, strongly influence BNF. However, the molecular mechanisms of these interactions are unclear. In this work, a physiological characterization of BNF and phosphorus mobilization (PM) from an insoluble form (Ca3(PO4)2) in Azotobacter chroococcum NCIMB 8003 was carried out. These processes were analyzed by quantitative proteomics in order to detect their molecular requirements and interactions. BNF led to a metabolic change beyond the proteins strictly necessary to carry out the process, including the metabolism related to other elements, like phosphorus. Also, changes in cell mobility, heme group synthesis and oxidative stress responses were observed. This study also revealed two phosphatases that seem to have the main role in PM, an exopolyphosphatase and a non-specific alkaline phosphatase PhoX. When both BNF and PM processes take place simultaneously, the synthesis of nitrogenous bases and L-methionine were also affected. Thus, although the interdependence is still unknown, possible biotechnological applications of these processes should take into account the indicated factors.
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Affiliation(s)
- Karolina A. Biełło
- Departamento de Bioquímica y Biología Molecular, Edificio Severo Ochoa, Campus de Rabanales, Universidad de Córdoba, Córdoba, Spain
| | - Carlos Lucena
- Departamento de Botánica, Ecología y Fisiología Vegetal, Edificio Celestino Mutis, Campus de Rabanales, Universidad de Córdoba, Córdoba, Spain
| | - Francisco J. López-Tenllado
- Departamento de Química Orgánica, Instituto Universitario de Investigación en Química Fina y Nanoquímica (IUNAN), Universidad de Córdoba, Córdoba, Spain
| | - Jesús Hidalgo-Carrillo
- Departamento de Química Orgánica, Instituto Universitario de Investigación en Química Fina y Nanoquímica (IUNAN), Universidad de Córdoba, Córdoba, Spain
| | - Gema Rodríguez-Caballero
- Departamento de Bioquímica y Biología Molecular, Edificio Severo Ochoa, Campus de Rabanales, Universidad de Córdoba, Córdoba, Spain
| | - Purificación Cabello
- Departamento de Botánica, Ecología y Fisiología Vegetal, Edificio Celestino Mutis, Campus de Rabanales, Universidad de Córdoba, Córdoba, Spain
| | - Lara P. Sáez
- Departamento de Bioquímica y Biología Molecular, Edificio Severo Ochoa, Campus de Rabanales, Universidad de Córdoba, Córdoba, Spain
| | - Víctor Luque-Almagro
- Departamento de Bioquímica y Biología Molecular, Edificio Severo Ochoa, Campus de Rabanales, Universidad de Córdoba, Córdoba, Spain
| | - María Dolores Roldán
- Departamento de Bioquímica y Biología Molecular, Edificio Severo Ochoa, Campus de Rabanales, Universidad de Córdoba, Córdoba, Spain
| | - Conrado Moreno-Vivián
- Departamento de Bioquímica y Biología Molecular, Edificio Severo Ochoa, Campus de Rabanales, Universidad de Córdoba, Córdoba, Spain
| | - Alfonso Olaya-Abril
- Departamento de Bioquímica y Biología Molecular, Edificio Severo Ochoa, Campus de Rabanales, Universidad de Córdoba, Córdoba, Spain,*Correspondence: Alfonso Olaya-Abril,
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4
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Nguyen TQ, Nicolet Y. Structure and Catalytic Mechanism of Radical SAM Methylases. Life (Basel) 2022; 12:1732. [PMID: 36362886 PMCID: PMC9692996 DOI: 10.3390/life12111732] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2022] [Revised: 10/25/2022] [Accepted: 10/26/2022] [Indexed: 08/14/2023] Open
Abstract
Methyl transfer is essential in myriad biological pathways found across all domains of life. Unlike conventional methyltransferases that catalyze this reaction through nucleophilic substitution, many members of the radical S-adenosyl-L-methionine (SAM) enzyme superfamily use radical-based chemistry to methylate unreactive carbon centers. These radical SAM methylases reductively cleave SAM to generate a highly reactive 5'-deoxyadenosyl radical, which initiates a broad range of transformations. Recently, crystal structures of several radical SAM methylases have been determined, shedding light on the unprecedented catalytic mechanisms used by these enzymes to overcome the substantial activation energy barrier of weakly nucleophilic substrates. Here, we review some of the discoveries on this topic over the last decade, focusing on enzymes for which three-dimensional structures are available to identify the key players in the mechanisms, highlighting the dual function of SAM as a methyl donor and a 5'-deoxyadenosyl radical or deprotonating base source. We also describe the role of the protein matrix in orchestrating the reaction through different strategies to catalyze such challenging methylations.
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Affiliation(s)
| | - Yvain Nicolet
- Metalloproteins Unit, Univ. Grenoble Alpes, CEA, CNRS, IBS, F-38000 Grenoble, France
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5
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Baysal C, Burén S, He W, Jiang X, Capell T, Rubio LM, Christou P. Functional expression of the nitrogenase Fe protein in transgenic rice. Commun Biol 2022; 5:1006. [PMID: 36198910 PMCID: PMC9534833 DOI: 10.1038/s42003-022-03921-9] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2022] [Accepted: 08/30/2022] [Indexed: 11/24/2022] Open
Abstract
Engineering cereals to express functional nitrogenase is a long-term goal of plant biotechnology and would permit partial or total replacement of synthetic N fertilizers by metabolization of atmospheric N2. Developing this technology is hindered by the genetic and biochemical complexity of nitrogenase biosynthesis. Nitrogenase and many of the accessory proteins involved in its assembly and function are O2 sensitive and only sparingly soluble in non-native hosts. We generated transgenic rice plants expressing the nitrogenase structural component, Fe protein (NifH), which carries a [4Fe-4S] cluster in its active form. NifH from Hydrogenobacter thermophilus was targeted to mitochondria together with the putative peptidyl prolyl cis-trans isomerase NifM from Azotobacter vinelandii to assist in NifH polypeptide folding. The isolated NifH was partially active in electron transfer to the MoFe protein nitrogenase component (NifDK) and in the biosynthesis of the nitrogenase iron-molybdenum cofactor (FeMo-co), two fundamental roles for NifH in N2 fixation. NifH functionality was, however, limited by poor [4Fe-4S] cluster occupancy, highlighting the importance of in vivo [Fe-S] cluster insertion and stability to achieve biological N2 fixation in planta. Nevertheless, the expression and activity of a nitrogenase component in rice plants represents the first major step to engineer functional nitrogenase in cereal crops.
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Affiliation(s)
- Can Baysal
- Department of Plant Production and Forestry Science, University of Lleida-Agrotecnio CERCA Center, Av. Alcalde Rovira Roure, 191, 25198, Lleida, Spain
- Department of Genetics, Cell Biology and Development, University of Minnesota, St. Paul, MN, USA
| | - Stefan Burén
- Centro de Biotecnología y Genómica de Plantas, Universidad Politécnica de Madrid (UPM) - Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria (INIA), Campus Montegancedo UPM, 28223, Pozuelo de Alarcón (Madrid), Spain
- Departamento de Biotecnología-Biología Vegetal, Escuela Técnica Superior de Ingeniería Agronómica, Alimentaria y de Biosistemas, Universidad Politécnica de Madrid, 28040, Madrid, Spain
| | - Wenshu He
- Department of Plant Production and Forestry Science, University of Lleida-Agrotecnio CERCA Center, Av. Alcalde Rovira Roure, 191, 25198, Lleida, Spain
| | - Xi Jiang
- Centro de Biotecnología y Genómica de Plantas, Universidad Politécnica de Madrid (UPM) - Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria (INIA), Campus Montegancedo UPM, 28223, Pozuelo de Alarcón (Madrid), Spain
- Departamento de Biotecnología-Biología Vegetal, Escuela Técnica Superior de Ingeniería Agronómica, Alimentaria y de Biosistemas, Universidad Politécnica de Madrid, 28040, Madrid, Spain
| | - Teresa Capell
- Department of Plant Production and Forestry Science, University of Lleida-Agrotecnio CERCA Center, Av. Alcalde Rovira Roure, 191, 25198, Lleida, Spain
| | - Luis M Rubio
- Centro de Biotecnología y Genómica de Plantas, Universidad Politécnica de Madrid (UPM) - Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria (INIA), Campus Montegancedo UPM, 28223, Pozuelo de Alarcón (Madrid), Spain.
- Departamento de Biotecnología-Biología Vegetal, Escuela Técnica Superior de Ingeniería Agronómica, Alimentaria y de Biosistemas, Universidad Politécnica de Madrid, 28040, Madrid, Spain.
| | - Paul Christou
- Department of Plant Production and Forestry Science, University of Lleida-Agrotecnio CERCA Center, Av. Alcalde Rovira Roure, 191, 25198, Lleida, Spain.
- ICREA, Catalan Institute for Research and Advanced Studies, Passeig Lluís Companys 23, 08010, Barcelona, Spain.
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6
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He W, Burén S, Baysal C, Jiang X, Capell T, Christou P, Rubio LM. Nitrogenase Cofactor Maturase NifB Isolated from Transgenic Rice is Active in FeMo-co Synthesis. ACS Synth Biol 2022; 11:3028-3036. [PMID: 35998307 PMCID: PMC9486962 DOI: 10.1021/acssynbio.2c00194] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Abstract
The engineering of nitrogen fixation in plants requires assembly of an active prokaryotic nitrogenase complex, which is yet to be achieved. Nitrogenase biogenesis relies on NifB, which catalyzes the formation of the [8Fe-9S-C] metal cluster NifB-co. This is the first committed step in the biosynthesis of the iron-molybdenum cofactor (FeMo-co) found at the nitrogenase active site. The production of NifB in plants is challenging because this protein is often insoluble in eukaryotic cells, and its [Fe-S] clusters are extremely unstable and sensitive to O2. As a first step to address this challenge, we generated transgenic rice plants expressing NifB from the Archaea Methanocaldococcus infernus and Methanothermobacter thermautotrophicus. The recombinant proteins were targeted to the mitochondria to limit exposure to O2 and to have access to essential [4Fe-4S] clusters required for NifB-co biosynthesis. M. infernus and M. thermautotrophicus NifB accumulated as soluble proteins in planta, and the purified proteins were functional in the in vitro FeMo-co synthesis assay. We thus report NifB protein expression and purification from an engineered staple crop, representing a first step in the biosynthesis of a functional NifDK complex, as required for independent biological nitrogen fixation in cereals.
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Affiliation(s)
- Wenshu He
- Department
of Plant Production and Forestry Science, University of Lleida-Agrotecnio CERCA Center, Av. Alcalde Rovira Roure, 191, 25198 Lleida, Spain
| | - Stefan Burén
- Centro
de Biotecnología y Genómica de Plantas, Universidad
Politécnica de Madrid (UPM), Instituto
Nacional de Investigación y Tecnología Agraria y Alimentaria
(INIA), Campus Montegancedo
UPM, Pozuelo de Alarcón, 28223 , Madrid, Spain,Departamento
de Biotecnología-Biología Vegetal, Escuela Técnica
Superior de Ingeniería Agronómica, Alimentaria y de
Biosistemas, Universidad Politécnica
de Madrid, 28040 Madrid, Spain
| | - Can Baysal
- Department
of Plant Production and Forestry Science, University of Lleida-Agrotecnio CERCA Center, Av. Alcalde Rovira Roure, 191, 25198 Lleida, Spain
| | - Xi Jiang
- Centro
de Biotecnología y Genómica de Plantas, Universidad
Politécnica de Madrid (UPM), Instituto
Nacional de Investigación y Tecnología Agraria y Alimentaria
(INIA), Campus Montegancedo
UPM, Pozuelo de Alarcón, 28223 , Madrid, Spain,Departamento
de Biotecnología-Biología Vegetal, Escuela Técnica
Superior de Ingeniería Agronómica, Alimentaria y de
Biosistemas, Universidad Politécnica
de Madrid, 28040 Madrid, Spain
| | - Teresa Capell
- Department
of Plant Production and Forestry Science, University of Lleida-Agrotecnio CERCA Center, Av. Alcalde Rovira Roure, 191, 25198 Lleida, Spain
| | - Paul Christou
- Department
of Plant Production and Forestry Science, University of Lleida-Agrotecnio CERCA Center, Av. Alcalde Rovira Roure, 191, 25198 Lleida, Spain,ICREA,
Catalan Institute for Research and Advanced Studies, Passeig Lluís Companys 23, 08010 Barcelona, Spain,
| | - Luis M. Rubio
- Centro
de Biotecnología y Genómica de Plantas, Universidad
Politécnica de Madrid (UPM), Instituto
Nacional de Investigación y Tecnología Agraria y Alimentaria
(INIA), Campus Montegancedo
UPM, Pozuelo de Alarcón, 28223 , Madrid, Spain,Departamento
de Biotecnología-Biología Vegetal, Escuela Técnica
Superior de Ingeniería Agronómica, Alimentaria y de
Biosistemas, Universidad Politécnica
de Madrid, 28040 Madrid, Spain,
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7
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Kramer BJ, Jankowiak JG, Nanjappa D, Harke MJ, Gobler CJ. Nitrogen and phosphorus significantly alter growth, nitrogen fixation, anatoxin-a content, and the transcriptome of the bloom-forming cyanobacterium, Dolichospermum. Front Microbiol 2022; 13:955032. [PMID: 36160233 PMCID: PMC9490380 DOI: 10.3389/fmicb.2022.955032] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2022] [Accepted: 08/19/2022] [Indexed: 11/27/2022] Open
Abstract
While freshwater cyanobacteria are traditionally thought to be limited by the availability of phosphorus (P), fixed nitrogen (N) supply can promote the growth and/or toxin production of some genera. This study characterizes how growth on N2 (control), nitrate (NO3 -), ammonium (NH4 +), and urea as well as P limitation altered the growth, toxin production, N2 fixation, and gene expression of an anatoxin-a (ATX-A) - producing strain of Dolichospermum sp. 54. The transcriptomes of fixed N and P-limited cultures differed significantly from those of fixed N-deplete, P-replete (control) cultures, while the transcriptomes of P-replete cultures amended with either NH4 + or NO3 - were not significantly different relative to those of the control. Growth rates of Dolichospermum (sp. 54) were significantly higher when grown on fixed N relative to without fixed N; growth on NH4 + was also significantly greater than growth on NO3 -. NH4 + and urea significantly lowered N2 fixation and nifD gene transcript abundance relative to the control while cultures amended with NO3 - exhibited N2 fixation and nifD gene transcript abundance that was not different from the control. Cultures grown on NH4 + exhibited the lowest ATX-A content per cell and lower transcript abundance of genes associated ATX-A synthesis (ana), while the abundance of transcripts of several ana genes were highest under fixed N and P - limited conditions. The significant negative correlation between growth rate and cellular anatoxin quota as well as the significantly higher number of transcripts of ana genes in cultures deprived of fixed N and P relative to P-replete cultures amended with NH4 + suggests ATX-A was being actively synthesized under P limitation. Collectively, these findings indicate that management strategies that do not regulate fixed N loading will leave eutrophic water bodies vulnerable to more intense and toxic (due to increased biomass) blooms of Dolichospermum.
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Affiliation(s)
- Benjamin J. Kramer
- School of Marine and Atmospheric Sciences, Stony Brook University, Southampton, NY, United States
| | | | - Deepak Nanjappa
- School of Marine and Atmospheric Sciences, Stony Brook University, Southampton, NY, United States
| | - Matthew J. Harke
- Gloucester Marine Genomics Institute, Gloucester, MA, United States
| | - Christopher J. Gobler
- School of Marine and Atmospheric Sciences, Stony Brook University, Southampton, NY, United States
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8
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Jiang X, Coroian D, Barahona E, Echavarri-Erasun C, Castellanos-Rueda R, Eseverri Á, Aznar-Moreno JA, Burén S, Rubio LM. Functional Nitrogenase Cofactor Maturase NifB in Mitochondria and Chloroplasts of Nicotiana benthamiana. mBio 2022; 13:e0026822. [PMID: 35695456 PMCID: PMC9239050 DOI: 10.1128/mbio.00268-22] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2022] [Accepted: 05/16/2022] [Indexed: 11/20/2022] Open
Abstract
Engineering plants to synthesize nitrogenase and assimilate atmospheric N2 will reduce crop dependency on industrial N fertilizers. This technology can be achieved by expressing prokaryotic nitrogen fixation gene products for the assembly of a functional nitrogenase in plants. NifB is a critical nitrogenase component since it catalyzes the first committed step in the biosynthesis of all types of nitrogenase active-site cofactors. Here, we used a library of 30 distinct nifB sequences originating from different phyla and ecological niches to restore diazotrophic growth of an Azotobacter vinelandii nifB mutant. Twenty of these variants rescued the nifB mutant phenotype despite their phylogenetic distance to A. vinelandii. Because multiple protein interactions are required in the iron-molybdenum cofactor (FeMo-co) biosynthetic pathway, the maturation of nitrogenase in a heterologous host can be divided in independent modules containing interacting proteins that function together to produce a specific intermediate. Therefore, nifB functional modules composed of a nifB variant, together with the A. vinelandii NifS and NifU proteins (for biosynthesis of NifB [Fe4S4] clusters) and the FdxN ferredoxin (for NifB function), were expressed in Nicotiana benthamiana chloroplasts and mitochondria. Three archaeal NifB proteins accumulated at high levels in soluble fractions of chloroplasts (Methanosarcina acetivorans and Methanocaldococcus infernus) or mitochondria (M. infernus and Methanothermobacter thermautotrophicus). These NifB proteins were shown to accept [Fe4S4] clusters from NifU and were functional in FeMo-co synthesis in vitro. The accumulation of significant levels of soluble and functional NifB proteins in chloroplasts and mitochondria is critical to engineering biological nitrogen fixation in plants. IMPORTANCE Biological nitrogen fixation is the conversion of inert atmospheric dinitrogen gas into nitrogen-reactive ammonia, a reaction catalyzed by the nitrogenase enzyme of diazotrophic bacteria and archaea. Because plants cannot fix their own nitrogen, introducing functional nitrogenase in cereals and other crop plants would reduce our strong dependency on N fertilizers. NifB is required for the biosynthesis of the active site cofactors of all nitrogenases, which arguably makes it the most important protein in global nitrogen fixation. NifB functionality is therefore a requisite to engineer a plant nitrogenase. The expression of nifB genes from a wide range of prokaryotes into the model diazotroph Azotobacter vinelandii shows a surprising level of genetic complementation suggestive of plasticity in the nitrogenase biosynthetic pathway. In addition, we obtained NifB proteins from both mitochondria and chloroplasts of tobacco that are functional in vitro after reconstitution by providing [Fe4S4] clusters from NifU, paving the way to nitrogenase cofactor biosynthesis in plants.
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Affiliation(s)
- Xi Jiang
- Centro de Biotecnología y Genómica de Plantas, Universidad Politécnica de Madrid, Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria, Pozuelo de Alarcón, Madrid, Spain
- Departamento de Biotecnología-Biología Vegetal, Escuela Técnica Superior de Ingeniería Agronómica, Alimentaria y de Biosistemas, Universidad Politécnica de Madrid, Madrid, Spain
| | - Diana Coroian
- Centro de Biotecnología y Genómica de Plantas, Universidad Politécnica de Madrid, Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria, Pozuelo de Alarcón, Madrid, Spain
| | - Emma Barahona
- Centro de Biotecnología y Genómica de Plantas, Universidad Politécnica de Madrid, Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria, Pozuelo de Alarcón, Madrid, Spain
| | - Carlos Echavarri-Erasun
- Centro de Biotecnología y Genómica de Plantas, Universidad Politécnica de Madrid, Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria, Pozuelo de Alarcón, Madrid, Spain
- Departamento de Biotecnología-Biología Vegetal, Escuela Técnica Superior de Ingeniería Agronómica, Alimentaria y de Biosistemas, Universidad Politécnica de Madrid, Madrid, Spain
| | - Rocío Castellanos-Rueda
- Centro de Biotecnología y Genómica de Plantas, Universidad Politécnica de Madrid, Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria, Pozuelo de Alarcón, Madrid, Spain
| | - Álvaro Eseverri
- Centro de Biotecnología y Genómica de Plantas, Universidad Politécnica de Madrid, Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria, Pozuelo de Alarcón, Madrid, Spain
| | - Jose A. Aznar-Moreno
- Centro de Biotecnología y Genómica de Plantas, Universidad Politécnica de Madrid, Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria, Pozuelo de Alarcón, Madrid, Spain
| | - Stefan Burén
- Centro de Biotecnología y Genómica de Plantas, Universidad Politécnica de Madrid, Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria, Pozuelo de Alarcón, Madrid, Spain
- Departamento de Biotecnología-Biología Vegetal, Escuela Técnica Superior de Ingeniería Agronómica, Alimentaria y de Biosistemas, Universidad Politécnica de Madrid, Madrid, Spain
| | - Luis M. Rubio
- Centro de Biotecnología y Genómica de Plantas, Universidad Politécnica de Madrid, Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria, Pozuelo de Alarcón, Madrid, Spain
- Departamento de Biotecnología-Biología Vegetal, Escuela Técnica Superior de Ingeniería Agronómica, Alimentaria y de Biosistemas, Universidad Politécnica de Madrid, Madrid, Spain
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9
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Nicolet Y, Cherrier MV, Amara P. Radical SAM Enzymes and Metallocofactor Assembly: A Structural Point of View. ACS BIO & MED CHEM AU 2022; 2:36-52. [PMID: 37102176 PMCID: PMC10114646 DOI: 10.1021/acsbiomedchemau.1c00044] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
This Review focuses on the structure-function relationship of radical S-adenosyl-l-methionine (SAM) enzymes involved in the assembly of metallocofactors corresponding to the active sites of [FeFe]-hydrogenase and nitrogenase [MoFe]-protein. It does not claim to correspond to an extensive review on the assembly machineries of these enzyme active sites, for which many good reviews are already available, but instead deals with the contribution of structural data to the understanding of their chemical mechanism (Buren et al. Chem. Rev.2020, 142 ( (25), ) 11006-11012; Britt et al. Chem. Sci.2020, 11 ( (38), ), 10313-10323). Hence, we will present the history and current knowledge about the radical SAM maturases HydE, HydG, and NifB as well as what, in our opinion, should be done in the near future to overcome the existing barriers in our understanding of this fascinating chemistry that intertwine organic radicals and organometallic complexes.
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Affiliation(s)
- Yvain Nicolet
- Univ. Grenoble Alpes, CEA, CNRS, IBS, Metalloproteins Unit, F-38000 Grenoble, France
| | - Mickael V. Cherrier
- Univ. Grenoble Alpes, CEA, CNRS, IBS, Metalloproteins Unit, F-38000 Grenoble, France
| | - Patricia Amara
- Univ. Grenoble Alpes, CEA, CNRS, IBS, Metalloproteins Unit, F-38000 Grenoble, France
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10
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Specificity of NifEN and VnfEN for the Assembly of Nitrogenase Active Site Cofactors in Azotobacter vinelandii. mBio 2021; 12:e0156821. [PMID: 34281397 PMCID: PMC8406325 DOI: 10.1128/mbio.01568-21] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The nitrogen-fixing microbe Azotobacter vinelandii has the ability to produce three genetically distinct, but mechanistically similar, components that catalyze nitrogen fixation. For two of these components, the Mo-dependent and V-dependent components, their corresponding metal-containing active site cofactors, designated FeMo-cofactor and FeV-cofactor, respectively, are preformed on separate molecular scaffolds designated NifEN and VnfEN, respectively. From prior studies, and the present work, it is now established that neither of these scaffolds can replace the other with respect to their in vivo cofactor assembly functions. Namely, a strain inactivated for NifEN cannot produce active Mo-dependent nitrogenase nor can a strain inactivated for VnfEN produce an active V-dependent nitrogenase. It is therefore proposed that metal specificities for FeMo-cofactor and FeV-cofactor formation are supplied by their respective assembly scaffolds. In the case of the third, Fe-only component, its associated active site cofactor, designated FeFe-cofactor, requires neither the NifEN nor VnfEN assembly scaffold for its formation. Furthermore, there are no other genes present in A. vinelandii that encode proteins having primary structure similarity to either NifEN or VnfEN. It is therefore concluded that FeFe-cofactor assembly is completed within its cognate catalytic protein partner without the aid of an intermediate assembly site. IMPORTANCE Biological nitrogen fixation is a complex process involving the nitrogenases. The biosynthesis of an active nitrogenase involves a large number of genes and the coordinated function of their products. Understanding the details of the assembly and activation of the different nitrogen fixation components, in particular the simplest one known so far, the Fe-only nitrogenase, would contribute to the goal of transferring the necessary genetic elements of bacterial nitrogen fixation to cereal crops to endow them with the capacity for self-fertilization. In this work, we show that there is no need for a scaffold complex for the assembly of the FeFe-cofactor, which provides the active site for Fe-only nitrogenase. These results are in agreement with previously reported genetic reconstruction experiments using a non-nitrogen-fixing microbe. In aggregate, these findings provide a high degree of confidence that the Fe-only system represents the simplest and, therefore, most attractive target for mobilizing nitrogen fixation into plants.
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11
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López‐Torrejón G, Burén S, Veldhuizen M, Rubio LM. Biosynthesis of cofactor-activatable iron-only nitrogenase in Saccharomyces cerevisiae. Microb Biotechnol 2021; 14:1073-1083. [PMID: 33507628 PMCID: PMC8085987 DOI: 10.1111/1751-7915.13758] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2020] [Revised: 01/04/2021] [Accepted: 01/07/2021] [Indexed: 12/02/2022] Open
Abstract
Engineering nitrogenase in eukaryotes is hampered by its genetic complexity and by the oxygen sensitivity of its protein components. Of the three types of nitrogenases, the Fe-only nitrogenase is considered the simplest one because its function depends on fewer gene products than the homologous and more complex Mo and V nitrogenases. Here, we show the expression of stable Fe-only nitrogenase component proteins in the low-oxygen mitochondria matrix of S. cerevisiae. As-isolated Fe protein (AnfH) was active in electron donation to NifDK to reduce acetylene into ethylene. Ancillary proteins NifU, NifS and NifM were not required for Fe protein function. The FeFe protein existed as apo-AnfDK complex with the AnfG subunit either loosely bound or completely unable to interact with it. Apo-AnfDK could be activated for acetylene reduction by the simple addition of FeMo-co in vitro, indicating preexistence of the P-clusters even in the absence of coexpressed NifU and NifS. This work reinforces the use of Fe-only nitrogenase as simple model to engineer nitrogen fixation in yeast and plant mitochondria.
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Affiliation(s)
- Gema López‐Torrejón
- Centro de Biotecnología y Genómica de PlantasUniversidad Politécnica de Madrid (UPM)Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria (INIA)Pozuelo de Alarcón, Madrid28223Spain
- Departamento de Biotecnología‐Biología VegetalEscuela Técnica Superior de Ingeniería AgronómicaAlimentaría y de BiosistemasUPMMadridSpain
| | - Stefan Burén
- Centro de Biotecnología y Genómica de PlantasUniversidad Politécnica de Madrid (UPM)Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria (INIA)Pozuelo de Alarcón, Madrid28223Spain
| | - Marcel Veldhuizen
- Centro de Biotecnología y Genómica de PlantasUniversidad Politécnica de Madrid (UPM)Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria (INIA)Pozuelo de Alarcón, Madrid28223Spain
| | - Luis M. Rubio
- Centro de Biotecnología y Genómica de PlantasUniversidad Politécnica de Madrid (UPM)Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria (INIA)Pozuelo de Alarcón, Madrid28223Spain
- Departamento de Biotecnología‐Biología VegetalEscuela Técnica Superior de Ingeniería AgronómicaAlimentaría y de BiosistemasUPMMadridSpain
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12
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Jenner LP, Cherrier MV, Amara P, Rubio LM, Nicolet Y. An unexpected P-cluster like intermediate en route to the nitrogenase FeMo-co. Chem Sci 2021; 12:5269-5274. [PMID: 34168778 PMCID: PMC8179604 DOI: 10.1039/d1sc00289a] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
The nitrogenase MoFe protein contains two different FeS centers, the P-cluster and the iron–molybdenum cofactor (FeMo-co). The former is a [Fe8S7] center responsible for conveying electrons to the latter, a [MoFe7S9C-(R)-homocitrate] species, where N2 reduction takes place. NifB is arguably the key enzyme in FeMo-co assembly as it catalyzes the fusion of two [Fe4S4] clusters and the insertion of carbide and sulfide ions to build NifB-co, a [Fe8S9C] precursor to FeMo-co. Recently, two crystal structures of NifB proteins were reported, one containing two out of three [Fe4S4] clusters coordinated by the protein which is likely to correspond to an early stage of the reaction mechanism. The other one was fully complemented with the three [Fe4S4] clusters (RS, K1 and K2), but was obtained at lower resolution and a satisfactory model was not obtained. Here we report improved processing of this crystallographic data. At odds with what was previously reported, this structure contains a unique [Fe8S8] cluster, likely to be a NifB-co precursor resulting from the fusion of K1- and K2-clusters. Strikingly, this new [Fe8S8] cluster has both a structure and coordination sphere geometry reminiscent of the fully reduced P-cluster (PN-state) with an additional μ2-bridging sulfide ion pointing toward the RS cluster. Comparison of available NifB structures further unveils the plasticity of this protein and suggests how ligand reorganization would accommodate cluster loading and fusion in the time-course of NifB-co synthesis. The K-cluster of NifB as a key intermediate in the synthesis of the nitrogenase active site supports [Fe4S4] cluster fusion occurs before carbide and sulfide insertion and displays ligand spatial arrangement reminiscent to that of the P-cluster.![]()
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Affiliation(s)
- Leon P Jenner
- Univ. Grenoble Alpes, CEA, CNRS, IBS, Metalloproteins Unit F-38000 Grenoble France
| | - Mickael V Cherrier
- Univ. Grenoble Alpes, CEA, CNRS, IBS, Metalloproteins Unit F-38000 Grenoble France
| | - Patricia Amara
- Univ. Grenoble Alpes, CEA, CNRS, IBS, Metalloproteins Unit F-38000 Grenoble France
| | - Luis M Rubio
- Centro de Biotecnología y Genómica de Plantas, Universidad Politécnica de Madrid, Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria Pozuelo de Alarcón 28223 Madrid Spain
| | - Yvain Nicolet
- Univ. Grenoble Alpes, CEA, CNRS, IBS, Metalloproteins Unit F-38000 Grenoble France
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13
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Jiang X, Payá-Tormo L, Coroian D, García-Rubio I, Castellanos-Rueda R, Eseverri Á, López-Torrejón G, Burén S, Rubio LM. Exploiting genetic diversity and gene synthesis to identify superior nitrogenase NifH protein variants to engineer N 2-fixation in plants. Commun Biol 2021; 4:4. [PMID: 33398015 PMCID: PMC7782807 DOI: 10.1038/s42003-020-01536-6] [Citation(s) in RCA: 26] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2020] [Accepted: 11/25/2020] [Indexed: 01/01/2023] Open
Abstract
Engineering nitrogen fixation in eukaryotes requires high expression of functional nitrogenase structural proteins, a goal that has not yet been achieved. Here we build a knowledge-based library containing 32 nitrogenase nifH sequences from prokaryotes of diverse ecological niches and metabolic features and combine with rapid screening in tobacco to identify superior NifH variants for plant mitochondria expression. Three NifH variants outperform in tobacco mitochondria and are further tested in yeast. Hydrogenobacter thermophilus (Aquificae) NifH is isolated in large quantities from yeast mitochondria and fulfills NifH protein requirements for efficient N2 fixation, including electron transfer for substrate reduction, P-cluster maturation, and FeMo-co biosynthesis. H. thermophilus NifH expressed in tobacco leaves shows lower nitrogenase activity than that from yeast. However, transfer of [Fe4S4] clusters from NifU to NifH in vitro increases 10-fold the activity of the tobacco-isolated NifH, revealing that plant mitochondria [Fe-S] cluster availability constitutes a bottleneck to engineer plant nitrogenases.
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Affiliation(s)
- Xi Jiang
- Centro de Biotecnología y Genómica de Plantas, Universidad Politécnica de Madrid, Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria, Pozuelo de Alarcón, 28223, Madrid, Spain
- Departamento de Biotecnología-Biología Vegetal, Escuela Técnica Superior de Ingeniería Agronómica, Alimentaría y de Biosistemas, Universidad Politécnica de Madrid, 28040, Madrid, Spain
| | - Lucía Payá-Tormo
- Centro de Biotecnología y Genómica de Plantas, Universidad Politécnica de Madrid, Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria, Pozuelo de Alarcón, 28223, Madrid, Spain
- Departamento de Biotecnología-Biología Vegetal, Escuela Técnica Superior de Ingeniería Agronómica, Alimentaría y de Biosistemas, Universidad Politécnica de Madrid, 28040, Madrid, Spain
| | - Diana Coroian
- Centro de Biotecnología y Genómica de Plantas, Universidad Politécnica de Madrid, Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria, Pozuelo de Alarcón, 28223, Madrid, Spain
| | - Inés García-Rubio
- Centro Universitario de la Defensa, Ctra. de Huesca s/n, 50090, Zaragoza, Spain
| | - Rocío Castellanos-Rueda
- Centro de Biotecnología y Genómica de Plantas, Universidad Politécnica de Madrid, Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria, Pozuelo de Alarcón, 28223, Madrid, Spain
- Department of Biosystems Science and Engineering, ETH Zürich, 4058, Basel, Switzerland
| | - Álvaro Eseverri
- Centro de Biotecnología y Genómica de Plantas, Universidad Politécnica de Madrid, Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria, Pozuelo de Alarcón, 28223, Madrid, Spain
- Departamento de Biotecnología-Biología Vegetal, Escuela Técnica Superior de Ingeniería Agronómica, Alimentaría y de Biosistemas, Universidad Politécnica de Madrid, 28040, Madrid, Spain
| | - Gema López-Torrejón
- Centro de Biotecnología y Genómica de Plantas, Universidad Politécnica de Madrid, Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria, Pozuelo de Alarcón, 28223, Madrid, Spain
- Departamento de Biotecnología-Biología Vegetal, Escuela Técnica Superior de Ingeniería Agronómica, Alimentaría y de Biosistemas, Universidad Politécnica de Madrid, 28040, Madrid, Spain
| | - Stefan Burén
- Centro de Biotecnología y Genómica de Plantas, Universidad Politécnica de Madrid, Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria, Pozuelo de Alarcón, 28223, Madrid, Spain.
| | - Luis Manuel Rubio
- Centro de Biotecnología y Genómica de Plantas, Universidad Politécnica de Madrid, Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria, Pozuelo de Alarcón, 28223, Madrid, Spain.
- Departamento de Biotecnología-Biología Vegetal, Escuela Técnica Superior de Ingeniería Agronómica, Alimentaría y de Biosistemas, Universidad Politécnica de Madrid, 28040, Madrid, Spain.
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14
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Eseverri Á, López‐Torrejón G, Jiang X, Burén S, Rubio LM, Caro E. Use of synthetic biology tools to optimize the production of active nitrogenase Fe protein in chloroplasts of tobacco leaf cells. PLANT BIOTECHNOLOGY JOURNAL 2020; 18:1882-1896. [PMID: 31985876 PMCID: PMC7415783 DOI: 10.1111/pbi.13347] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/31/2019] [Revised: 01/13/2020] [Accepted: 01/15/2020] [Indexed: 05/07/2023]
Abstract
The generation of nitrogen fixing crops is considered a challenge that could lead to a new agricultural 'green' revolution. Here, we report the use of synthetic biology tools to achieve and optimize the production of active nitrogenase Fe protein (NifH) in the chloroplasts of tobacco plants. Azotobacter vinelandii nitrogen fixation genes, nifH, M, U and S, were re-designed for protein accumulation in tobacco cells. Targeting to the chloroplast was optimized by screening and identifying minimal length transit peptides performing properly for each specific Nif protein. Putative peptidyl-prolyl cis-trans isomerase NifM proved necessary for NifH solubility in the stroma. Purified NifU, a protein involved in the biogenesis of NifH [4Fe-4S] cluster, was found functional in NifH reconstitution assays. Importantly, NifH purified from tobacco chloroplasts was active in the reduction of acetylene to ethylene, with the requirement of nifU and nifS co-expression. These results support the suitability of chloroplasts to host functional nitrogenase proteins, paving the way for future studies in the engineering of nitrogen fixation in higher plant plastids and describing an optimization pipeline that could also be used in other organisms and in the engineering of new metabolic pathways in plastids.
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Affiliation(s)
- Álvaro Eseverri
- Centre for Plant Biotechnology and GenomicsInstituto Nacional de Investigación y Tecnología Agraria y Alimentaria (INIA)Universidad Politécnica de Madrid (UPM)MadridSpain
| | - Gema López‐Torrejón
- Centre for Plant Biotechnology and GenomicsInstituto Nacional de Investigación y Tecnología Agraria y Alimentaria (INIA)Universidad Politécnica de Madrid (UPM)MadridSpain
- Departamento de Biotecnología-Biología Ve ge talEscuela Técnica Superior de Ingeniería AgronómicaAlimentaría y de BiosistemasUniversidad Politécnica de MadridMadridSpain
| | - Xi Jiang
- Centre for Plant Biotechnology and GenomicsInstituto Nacional de Investigación y Tecnología Agraria y Alimentaria (INIA)Universidad Politécnica de Madrid (UPM)MadridSpain
| | - Stefan Burén
- Centre for Plant Biotechnology and GenomicsInstituto Nacional de Investigación y Tecnología Agraria y Alimentaria (INIA)Universidad Politécnica de Madrid (UPM)MadridSpain
| | - Luis M. Rubio
- Centre for Plant Biotechnology and GenomicsInstituto Nacional de Investigación y Tecnología Agraria y Alimentaria (INIA)Universidad Politécnica de Madrid (UPM)MadridSpain
- Departamento de Biotecnología-Biología Ve ge talEscuela Técnica Superior de Ingeniería AgronómicaAlimentaría y de BiosistemasUniversidad Politécnica de MadridMadridSpain
| | - Elena Caro
- Centre for Plant Biotechnology and GenomicsInstituto Nacional de Investigación y Tecnología Agraria y Alimentaria (INIA)Universidad Politécnica de Madrid (UPM)MadridSpain
- Departamento de Biotecnología-Biología Ve ge talEscuela Técnica Superior de Ingeniería AgronómicaAlimentaría y de BiosistemasUniversidad Politécnica de MadridMadridSpain
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15
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Abstract
The enzyme molybdenum nitrogenase converts atmospheric nitrogen gas to ammonia and is of critical importance for the cycling of nitrogen in the biosphere and for the sustainability of life. Alternative vanadium and iron-only nitrogenases that are homologous to molybdenum nitrogenases are also found in archaea and bacteria, but they have a different transition metal, either vanadium or iron, at their active sites. So far alternative nitrogenases have only been found in microbes that also have molybdenum nitrogenase. They are less widespread than molybdenum nitrogenase in bacteria and archaea, and they are less efficient. The presumption has been that alternative nitrogenases are fail-safe enzymes that are used in situations where molybdenum is limiting. Recent work indicates that vanadium nitrogenase may play a role in the global biological nitrogen cycle and iron-only nitrogenase may contribute products that shape microbial community interactions in nature.
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Affiliation(s)
- Caroline S Harwood
- Department of Microbiology, University of Washington, Seattle, Washington 98195, USA;
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16
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Burén S, Jiménez-Vicente E, Echavarri-Erasun C, Rubio LM. Biosynthesis of Nitrogenase Cofactors. Chem Rev 2020; 120:4921-4968. [PMID: 31975585 PMCID: PMC7318056 DOI: 10.1021/acs.chemrev.9b00489] [Citation(s) in RCA: 106] [Impact Index Per Article: 26.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2019] [Indexed: 12/30/2022]
Abstract
Nitrogenase harbors three distinct metal prosthetic groups that are required for its activity. The simplest one is a [4Fe-4S] cluster located at the Fe protein nitrogenase component. The MoFe protein component carries an [8Fe-7S] group called P-cluster and a [7Fe-9S-C-Mo-R-homocitrate] group called FeMo-co. Formation of nitrogenase metalloclusters requires the participation of the structural nitrogenase components and many accessory proteins, and occurs both in situ, for the P-cluster, and in external assembly sites for FeMo-co. The biosynthesis of FeMo-co is performed stepwise and involves molecular scaffolds, metallochaperones, radical chemistry, and novel and unique biosynthetic intermediates. This review provides a critical overview of discoveries on nitrogenase cofactor structure, function, and activity over the last four decades.
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Affiliation(s)
- Stefan Burén
- Centro
de Biotecnología y Genómica de Plantas, Universidad Politécnica de Madrid (UPM), Instituto
Nacional de Investigación y Tecnología Agraria
y Alimentaria (INIA), Pozuelo de Alarcón, 28223 Madrid, Spain
| | - Emilio Jiménez-Vicente
- Department
of Biochemistry, Virginia Polytechnic Institute, Blacksburg, Virginia 24061, United States
| | - Carlos Echavarri-Erasun
- Centro
de Biotecnología y Genómica de Plantas, Universidad Politécnica de Madrid (UPM), Instituto
Nacional de Investigación y Tecnología Agraria
y Alimentaria (INIA), Pozuelo de Alarcón, 28223 Madrid, Spain
| | - Luis M. Rubio
- Centro
de Biotecnología y Genómica de Plantas, Universidad Politécnica de Madrid (UPM), Instituto
Nacional de Investigación y Tecnología Agraria
y Alimentaria (INIA), Pozuelo de Alarcón, 28223 Madrid, Spain
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17
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Garcia AK, McShea H, Kolaczkowski B, Kaçar B. Reconstructing the evolutionary history of nitrogenases: Evidence for ancestral molybdenum-cofactor utilization. GEOBIOLOGY 2020; 18:394-411. [PMID: 32065506 PMCID: PMC7216921 DOI: 10.1111/gbi.12381] [Citation(s) in RCA: 42] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/25/2019] [Revised: 12/23/2019] [Accepted: 01/22/2020] [Indexed: 05/08/2023]
Abstract
The nitrogenase metalloenzyme family, essential for supplying fixed nitrogen to the biosphere, is one of life's key biogeochemical innovations. The three forms of nitrogenase differ in their metal dependence, each binding either a FeMo-, FeV-, or FeFe-cofactor where the reduction of dinitrogen takes place. The history of nitrogenase metal dependence has been of particular interest due to the possible implication that ancient marine metal availabilities have significantly constrained nitrogenase evolution over geologic time. Here, we reconstructed the evolutionary history of nitrogenases, and combined phylogenetic reconstruction, ancestral sequence inference, and structural homology modeling to evaluate the potential metal dependence of ancient nitrogenases. We find that active-site sequence features can reliably distinguish extant Mo-nitrogenases from V- and Fe-nitrogenases and that inferred ancestral sequences at the deepest nodes of the phylogeny suggest these ancient proteins most resemble modern Mo-nitrogenases. Taxa representing early-branching nitrogenase lineages lack one or more biosynthetic nifE and nifN genes that both contribute to the assembly of the FeMo-cofactor in studied organisms, suggesting that early Mo-nitrogenases may have utilized an alternate and/or simplified pathway for cofactor biosynthesis. Our results underscore the profound impacts that protein-level innovations likely had on shaping global biogeochemical cycles throughout the Precambrian, in contrast to organism-level innovations that characterize the Phanerozoic Eon.
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Affiliation(s)
- Amanda K. Garcia
- Department of Molecular and Cellular BiologyUniversity of ArizonaTucsonArizona
| | - Hanon McShea
- Department of Earth System ScienceStanford UniversityStanfordCalifornia
| | - Bryan Kolaczkowski
- Department of Microbiology and Cell ScienceUniversity of FloridaGainesvilleFlorida
| | - Betül Kaçar
- Department of Molecular and Cellular BiologyUniversity of ArizonaTucsonArizona
- Steward Observatory and the Lunar and Planetary LaboratoryUniversity of ArizonaTucsonArizona
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18
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Biosynthesis of the nitrogenase active-site cofactor precursor NifB-co in Saccharomyces cerevisiae. Proc Natl Acad Sci U S A 2019; 116:25078-25086. [PMID: 31767756 PMCID: PMC6911178 DOI: 10.1073/pnas.1904903116] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
The radical S-adenosylmethionine (SAM) enzyme NifB occupies a central and essential position in nitrogenase biogenesis. NifB catalyzes the formation of an [8Fe-9S-C] cluster, called NifB-co, which constitutes the core of the active-site cofactors for all 3 nitrogenase types. Here, we produce functional NifB in aerobically cultured Saccharomyces cerevisiae Combinatorial pathway design was employed to construct 62 strains in which transcription units driving different expression levels of mitochondria-targeted nif genes (nifUSXB and fdxN) were integrated into the chromosome. Two combinatorial libraries totaling 0.7 Mb were constructed: An expression library of 6 partial clusters, including nifUSX and fdxN, and a library consisting of 28 different nifB genes mined from the Structure-Function Linkage Database and expressed at different levels according to a factorial design. We show that coexpression in yeast of the nitrogenase maturation proteins NifU, NifS, and FdxN from Azotobacter vinelandii with NifB from the archaea Methanocaldococcus infernus or Methanothermobacter thermautotrophicus yields NifB proteins equipped with [Fe-S] clusters that, as purified, support in vitro formation of NifB-co. Proof of in vivo NifB-co formation was additionally obtained. NifX as purified from aerobically cultured S. cerevisiae coexpressing M. thermautotrophicus NifB with A. vinelandii NifU, NifS, and FdxN, and engineered yeast SAM synthase supported FeMo-co synthesis, indicative of NifX carrying in vivo-formed NifB-co. This study defines the minimal genetic determinants for the formation of the key precursor in the nitrogenase cofactor biosynthetic pathway in a eukaryotic organism.
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19
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Mus F, Colman DR, Peters JW, Boyd ES. Geobiological feedbacks, oxygen, and the evolution of nitrogenase. Free Radic Biol Med 2019; 140:250-259. [PMID: 30735835 DOI: 10.1016/j.freeradbiomed.2019.01.050] [Citation(s) in RCA: 44] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/23/2018] [Accepted: 01/31/2019] [Indexed: 12/21/2022]
Abstract
Biological nitrogen fixation via the activity of nitrogenase is one of the most important biological innovations, allowing for an increase in global productivity that eventually permitted the emergence of higher forms of life. The complex metalloenzyme termed nitrogenase contains complex iron-sulfur cofactors. Three versions of nitrogenase exist that differ mainly by the presence or absence of a heterometal at the active site metal cluster (either Mo or V). Mo-dependent nitrogenase is the most common while V-dependent or heterometal independent (Fe-only) versions are often termed alternative nitrogenases since they have apparent lower activities for N2 reduction and are expressed in the absence of Mo. Phylogenetic data indicates that biological nitrogen fixation emerged in an anaerobic, thermophilic ancestor of hydrogenotrophic methanogens and later diversified via lateral gene transfer into anaerobic bacteria, and eventually aerobic bacteria including Cyanobacteria. Isotopic evidence suggests that nitrogenase activity existed at 3.2 Ga, prior to the advent of oxygenic photosynthesis and rise of oxygen in the atmosphere, implying the presence of favorable environmental conditions for oxygen-sensitive nitrogenase to evolve. Following the proliferation of oxygenic phototrophs, diazotrophic organisms had to develop strategies to protect nitrogenase from oxygen inactivation and generate the right balance of low potential reducing equivalents and cellular energy for growth and nitrogen fixation activity. Here we review the fundamental advances in our understanding of biological nitrogen fixation in the context of the emergence, evolution, and taxonomic distribution of nitrogenase, with an emphasis placed on key events associated with its emergence and diversification from anoxic to oxic environments.
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Affiliation(s)
- Florence Mus
- Institute of Biological Chemistry, Washington State University, Pullman, WA, USA
| | - Daniel R Colman
- Department of Microbiology and Immunology, Montana State University, Bozeman, MT, USA
| | - John W Peters
- Institute of Biological Chemistry, Washington State University, Pullman, WA, USA.
| | - Eric S Boyd
- Department of Microbiology and Immunology, Montana State University, Bozeman, MT, USA.
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20
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Liu X, Wang M, Song Y, Li Y, Liu P, Shi H, Li Y, Hao T, Zhang H, Jiang W, Chen S, Li J. Combined Assembly and Targeted Integration of Multigene for Nitrogenase Biosynthetic Pathway in Saccharomyces cerevisiae. ACS Synth Biol 2019; 8:1766-1775. [PMID: 31117360 DOI: 10.1021/acssynbio.9b00060] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Biological nitrogen fixation, a process unique to diazotrophic prokaryote, is catalyzed by the nitrogenase complex. There has been a long-standing interest in reconstituting a nitrogenase biosynthetic pathway in a eukaryotic host with the final aim of developing N2-fixing cereal crops. In this study, we report that a nitrogenase biosynthetic pathway (∼38 kb containing 15 genes) was assembled in two individual one-step methods via in vivo assembly and integrated at δ and HO sites in Saccharomyces cerevisiae chromosome. Of the 15 genes, 11 genes (nifB, nifH, nifD, nifK, nifE, nifN, nifX, hesA, nifV, groES, groEL) were from Paenibacillus polymyxa WLY78 and 4 genes (nifS, nifU, nifF, nifJ) were from Klebsiella oxytoca. The 15-gene nitrogenase biosynthetic pathway was correctly assembled and transcribed in the recombinant S. cerevisiae. The NifDK tetramer with an identical molecular weight as that of P. polymyxa was formed in yeast and the expressed NifH exhibited the activity of Fe protein. This study demonstrates that it will be possible to produce active nitrogenase in eukaryotic hosts.
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Affiliation(s)
- Xiaomeng Liu
- State Key Laboratory for Agrobiotechnology, College of Biological Sciences and Key Laboratory of Soil Microbiology of Agriculture Ministry, China Agricultural University, Beijing, P. R. China
| | - Minyang Wang
- State Key Laboratory for Agrobiotechnology, College of Biological Sciences and Key Laboratory of Soil Microbiology of Agriculture Ministry, China Agricultural University, Beijing, P. R. China
| | - Yi Song
- State Key Laboratory for Agrobiotechnology, College of Biological Sciences and Key Laboratory of Soil Microbiology of Agriculture Ministry, China Agricultural University, Beijing, P. R. China
| | - Yongbin Li
- State Key Laboratory for Agrobiotechnology, College of Biological Sciences and Key Laboratory of Soil Microbiology of Agriculture Ministry, China Agricultural University, Beijing, P. R. China
| | - Pengxi Liu
- State Key Laboratory for Agrobiotechnology, College of Biological Sciences and Key Laboratory of Soil Microbiology of Agriculture Ministry, China Agricultural University, Beijing, P. R. China
| | - Haowen Shi
- State Key Laboratory for Agrobiotechnology, College of Biological Sciences and Key Laboratory of Soil Microbiology of Agriculture Ministry, China Agricultural University, Beijing, P. R. China
| | - Yunlong Li
- State Key Laboratory for Agrobiotechnology, College of Biological Sciences and Key Laboratory of Soil Microbiology of Agriculture Ministry, China Agricultural University, Beijing, P. R. China
| | - Tianyi Hao
- State Key Laboratory for Agrobiotechnology, College of Biological Sciences and Key Laboratory of Soil Microbiology of Agriculture Ministry, China Agricultural University, Beijing, P. R. China
| | - Haowei Zhang
- State Key Laboratory for Agrobiotechnology, College of Biological Sciences and Key Laboratory of Soil Microbiology of Agriculture Ministry, China Agricultural University, Beijing, P. R. China
| | - Wei Jiang
- State Key Laboratory for Agrobiotechnology, College of Biological Sciences and Key Laboratory of Soil Microbiology of Agriculture Ministry, China Agricultural University, Beijing, P. R. China
| | - Sanfeng Chen
- State Key Laboratory for Agrobiotechnology, College of Biological Sciences and Key Laboratory of Soil Microbiology of Agriculture Ministry, China Agricultural University, Beijing, P. R. China
| | - Jilun Li
- State Key Laboratory for Agrobiotechnology, College of Biological Sciences and Key Laboratory of Soil Microbiology of Agriculture Ministry, China Agricultural University, Beijing, P. R. China
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21
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Zhang S, Kim SM. Synthesis, characterization, antioxidant and anti‐diabetic activities of a novel protein–vanadium complex. Appl Organomet Chem 2019. [DOI: 10.1002/aoc.5102] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Affiliation(s)
- Shuang Zhang
- Heilongjiang Provincial Key Laboratory of Environmental Microbiology and Recycling of Argo‐Waste in Cold Region, College of Life Science and BiotechnologyHeilongjiang Bayi Agricultural University Daqing Heilongjiang Province 163319 PR China
- Department of Marine Food Science and TechnologyGangneung‐Wonju National University Gangneung Gangwon‐do 25457 Republic of Korea
| | - Sang Moo Kim
- Department of Marine Food Science and TechnologyGangneung‐Wonju National University Gangneung Gangwon‐do 25457 Republic of Korea
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22
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Han X, Huang K, Tang H, Ni J, Liu J, Xu P, Tao F. Steps Toward High-Performance PLA: Economical Production of d-Lactate Enabled by a Newly Isolated Sporolactobacillus terrae Strain. Biotechnol J 2019; 14:e1800656. [PMID: 30810274 DOI: 10.1002/biot.201800656] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2018] [Revised: 12/21/2018] [Indexed: 11/10/2022]
Abstract
Optically pure d-lactate production has received much attention for its critical role in high-performance polylactic acid production. However, the current technology can hardly meet the comprehensive demand of industrialization on final titer, productivity, optical purity, and raw material costs. Here, an efficient d-lactate producer strain, Sporolactobacillus terrae (S. terrae) HKM-1, is isolated for d-lactate production. The strain HKM-1 shows extremely high d-lactate fermentative capability by using peanut meal, soybean meal, or corn steep liquor powder as a sole nitrogen source; the final titers (205.7 g L-1 , 218.9 g L-1 , and 193.9 g L-1 , respectively) and productivities (5.56 g L-1 h-1 , 5.34 g L-1 h-1 , and 3.73 g L-1 h-1 , respectively) of d-lactate reached the highest level ever reported. A comparative genomic analysis between S. terrae HKM-1 and previously reported d-lactate high-producing Sporolactobacillus inulinus (S. inulinus) CASD is conducted. The results show that many unrelated genetic features may contribute to the superior performance in d-lactate production of S. terrae HKM-1. This d-lactate producer HKM-1, along with its fermentation process, is promising for sustainable d-lactate production by using agro-industrial wastes.
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Affiliation(s)
- Xiao Han
- State Key Laboratory of Microbial Metabolism Joint International Research Laboratory of Metabolic and Developmental Sciences and School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai,, P. R. China
| | - Kaiming Huang
- State Key Laboratory of Microbial Metabolism Joint International Research Laboratory of Metabolic and Developmental Sciences and School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai,, P. R. China
| | - Hongzhi Tang
- State Key Laboratory of Microbial Metabolism Joint International Research Laboratory of Metabolic and Developmental Sciences and School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai,, P. R. China
| | - Jun Ni
- State Key Laboratory of Microbial Metabolism Joint International Research Laboratory of Metabolic and Developmental Sciences and School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai,, P. R. China
| | - Jiongqin Liu
- State Key Laboratory of Microbial Metabolism Joint International Research Laboratory of Metabolic and Developmental Sciences and School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai,, P. R. China
| | - Ping Xu
- State Key Laboratory of Microbial Metabolism Joint International Research Laboratory of Metabolic and Developmental Sciences and School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai,, P. R. China
| | - Fei Tao
- State Key Laboratory of Microbial Metabolism Joint International Research Laboratory of Metabolic and Developmental Sciences and School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai,, P. R. China
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23
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Navarro-Rodríguez M, Buesa JM, Rubio LM. Genetic and Biochemical Analysis of the Azotobacter vinelandii Molybdenum Storage Protein. Front Microbiol 2019; 10:579. [PMID: 30984129 PMCID: PMC6448029 DOI: 10.3389/fmicb.2019.00579] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2019] [Accepted: 03/06/2019] [Indexed: 11/13/2022] Open
Abstract
The N2 fixing bacterium Azotobacter vinelandii carries a molybdenum storage protein, referred to as MoSto, able to bind 25-fold more Mo than needed for maximum activity of its Mo nitrogenase. Here we have investigated a plausible role of MoSto as obligate intermediate in the pathway that provides Mo for the biosynthesis of nitrogenase iron-molybdenum cofactor (FeMo-co). The in vitro FeMo-co synthesis and insertion assay demonstrated that purified MoSto functions as Mo donor and that direct interaction with FeMo-co biosynthetic proteins stimulated Mo donation. The phenotype of an A. vinelandii strain lacking the MoSto subunit genes (ΔmosAB) was analyzed. Consistent with its role as storage protein, the ΔmosAB strain showed severe impairment to accumulate intracellular Mo and lower resilience than wild type to Mo starvation as demonstrated by decreased in vivo nitrogenase activity and competitive growth index. In addition, it was more sensitive than the wild type to diazotrophic growth inhibition by W. The ΔmosAB strain was found to readily derepress vnfDGK upon Mo step down, in contrast to the wild type that derepressed Vnf proteins only after prolonged Mo starvation. The ΔmosAB mutation was then introduced in a strain lacking V and Fe-only nitrogenase structural genes (Δvnf Δanf) to investigate possible compensations from these alternative systems. When grown in Mo-depleted medium, the ΔmosAB and mosAB + strains showed low but similar nitrogenase activities regardless of the presence of Vnf proteins. This study highlights the selective advantage that MoSto confers to A. vinelandii in situations of metal limitation as those found in many soil ecosystems. Such a favorable trait should be included in the gene complement of future nitrogen fixing plants.
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Affiliation(s)
- Mónica Navarro-Rodríguez
- Centro de Biotecnología y Genómica de Plantas (CBGP), Universidad Politécnica de Madrid (UPM), Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria (INIA), Madrid, Spain
| | - José María Buesa
- Centro de Biotecnología y Genómica de Plantas (CBGP), Universidad Politécnica de Madrid (UPM), Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria (INIA), Madrid, Spain
| | - Luis M Rubio
- Centro de Biotecnología y Genómica de Plantas (CBGP), Universidad Politécnica de Madrid (UPM), Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria (INIA), Madrid, Spain
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24
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Nonaka A, Yamamoto H, Kamiya N, Kotani H, Yamakawa H, Tsujimoto R, Fujita Y. Accessory Proteins of the Nitrogenase Assembly, NifW, NifX/NafY, and NifZ, Are Essential for Diazotrophic Growth in the Nonheterocystous Cyanobacterium Leptolyngbya boryana. Front Microbiol 2019; 10:495. [PMID: 30930880 PMCID: PMC6428710 DOI: 10.3389/fmicb.2019.00495] [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] [Received: 10/10/2018] [Accepted: 02/26/2019] [Indexed: 12/13/2022] Open
Abstract
Since nitrogenase is extremely vulnerable to oxygen, aerobic or micro-aerobic nitrogen-fixing organisms need to create anaerobic microenvironments in the cells for diazotrophic growth, which would be one of the major barriers to express active nitrogenase in plants in efforts to create nitrogen-fixing plants. Numerous cyanobacteria are able to fix nitrogen with nitrogenase by coping with the endogenous oxygen production by photosynthesis. Understanding of the molecular mechanisms enabling to the coexistence of nitrogen fixation and photosynthesis in nonheterocystous cyanobacteria could offer valuable insights for the transfer of nitrogen fixation capacity into plants. We previously identified the cnfR gene encoding the master regulator for the nitrogen fixation (nif) gene cluster in the genome of a nonheterocystous cyanobacterium Leptolyngbya boryana, in addition to initial characterization of the nif gene cluster. Here we isolated nine mutants, in which the nif and nif-related genes were individually knocked out in L. boryana to investigate the individual functions of (1) accessory proteins (NifW, NifX/NafY, and NifZ) in the biosynthesis of nitrogenase metallocenters, (2) serine acetyltransferase (NifP) in cysteine supply for iron-sulfur clusters, (3) pyruvate formate lyase in anaerobic metabolism, and (4) NifT and HesAB proteins. ΔnifW, ΔnifXnafY, and ΔnifZ exhibited the most severe phenotype characterized by low nitrogenase activity (<10%) and loss of diazotrophic growth ability. The phenotypes of ΔnifX, ΔnafY, and ΔnifXnafY suggested that the functions of the homologous proteins NifX and NafY partially overlap. ΔnifP exhibited significantly slower diazotrophic growth than the wild type, with lower nitrogenase activity (22%). The other four mutants (ΔpflB, ΔnifT, ΔhesA, and ΔhesB) grew diazotrophically similar to the wild type. Western blot analysis revealed a high correlation between nitrogenase activity and NifD contents, suggesting that NifD is more susceptible to proteolytic degradation than NifK in L. boryana. The phenotype of the mutants lacking the accessory proteins was more severe than that observed in heterotrophic bacteria such as Azotobacter vinelandii, which suggests that the functions of NifW, NifX/NafY, and NifZ are critical for diazotrophic growth of oxygenic photosynthetic cells. L. boryana provides a promising model for studying the molecular mechanisms that produce active nitrogenase, to facilitate the creation of nitrogen-fixing plants.
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Affiliation(s)
- Aoi Nonaka
- School of Agricultural Sciences, Nagoya University, Nagoya, Japan
| | - Haruki Yamamoto
- Graduate School of Bioagricultural Sciences, Nagoya University, Nagoya, Japan
| | - Narumi Kamiya
- School of Agricultural Sciences, Nagoya University, Nagoya, Japan
| | - Hiroya Kotani
- Graduate School of Bioagricultural Sciences, Nagoya University, Nagoya, Japan
| | - Hisanori Yamakawa
- Graduate School of Bioagricultural Sciences, Nagoya University, Nagoya, Japan
| | - Ryoma Tsujimoto
- Graduate School of Bioagricultural Sciences, Nagoya University, Nagoya, Japan
| | - Yuichi Fujita
- School of Agricultural Sciences, Nagoya University, Nagoya, Japan.,Graduate School of Bioagricultural Sciences, Nagoya University, Nagoya, Japan
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25
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Liu X, Zhao X, Li X, Chen S. Suppression of hesA mutation on nitrogenase activity in Paenibacillus polymyxa WLY78 with the addition of high levels of molybdate or cystine. PeerJ 2019; 7:e6294. [PMID: 30723617 PMCID: PMC6361004 DOI: 10.7717/peerj.6294] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2018] [Accepted: 12/17/2018] [Indexed: 12/02/2022] Open
Abstract
The diazotrophic Paenibacillus polymyxa WLY78 possesses a minimal nitrogen fixation gene cluster consisting of nine genes (nifB nifH nifD nifK nifE nifN nifX hesA and nifV). Notably, the hesA gene contained within the nif gene cluster is also found within nif gene clusters among diazotrophic cyanobacteria and Frankia. The predicted product HesA is a member of the ThiF-MoeB-HesA family containing an N-terminal nucleotide binding domain and a C-terminal MoeZ/MoeB-like domain. However, the function of hesA gene in nitrogen fixation is unknown. In this study, we demonstrate that the hesA mutation of P. polymyxa WLY78 leads to nearly complete loss of nitrogenase activity. The effect of the mutation can be partially suppressed by the addition of high levels of molybdate or cystine. However, the nitrogenase activity of the hesA mutant could not be restored by Klebsiella oxytoca nifQ or Escherichia coli moeB completely. In addition, the hesA mutation does not affect nitrate reductase activity of P. polymyxa WLY78. Our results demonstrate hesA is a novel gene specially required for nitrogen fixation and its role is related to introduction of S and Mo into the FeMo-co of nitrogenase.
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Affiliation(s)
- Xiaomeng Liu
- State Key Laboratory of Agrobiotechnology and College of Biological Sciences, China Agricultural University, Beijing, China
| | - Xiyun Zhao
- State Key Laboratory of Agrobiotechnology and College of Biological Sciences, China Agricultural University, Beijing, China
| | - Xiaohan Li
- State Key Laboratory of Agrobiotechnology and College of Biological Sciences, China Agricultural University, Beijing, China
| | - Sanfeng Chen
- State Key Laboratory of Agrobiotechnology and College of Biological Sciences, China Agricultural University, Beijing, China
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26
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Arragain S, Jiménez-Vicente E, Scandurra AA, Burén S, Rubio LM, Echavarri-Erasun C. Diversity and Functional Analysis of the FeMo-Cofactor Maturase NifB. FRONTIERS IN PLANT SCIENCE 2017; 8:1947. [PMID: 29250084 PMCID: PMC5715403 DOI: 10.3389/fpls.2017.01947] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 05/31/2017] [Accepted: 10/30/2017] [Indexed: 06/07/2023]
Abstract
One of the main hurdles to engineer nitrogenase in a non-diazotrophic host is achieving NifB activity. NifB is an extremely unstable and oxygen sensitive protein that catalyzes a low-potential SAM-radical dependent reaction. The product of NifB activity is called NifB-co, a complex [8Fe-9S-C] cluster that serves as obligate intermediate in the biosyntheses of the active-site cofactors of all known nitrogenases. Here we study the diversity and phylogeny of naturally occurring NifB proteins, their protein architecture and the functions of the distinct NifB domains in order to understand what defines a catalytically active NifB. Focus is on NifB from the thermophile Chlorobium tepidum (two-domain architecture), the hyperthermophile Methanocaldococcus infernus (single-domain architecture) and the mesophile Klebsiella oxytoca (two-domain architecture), showing in silico characterization of their nitrogen fixation (nif) gene clusters, conserved NifB motifs, and functionality. C. tepidum and M. infernus NifB were able to complement an Azotobacter vinelandii (ΔnifB) mutant restoring the Nif+ phenotype and thus demonstrating their functionality in vivo. In addition, purified C. tepidum NifB exhibited activity in the in vitro NifB-dependent nitrogenase reconstitution assay. Intriguingly, changing the two-domain K. oxytoca NifB to single-domain by removal of the C-terminal NifX-like extension resulted in higher in vivo nitrogenase activity, demonstrating that this domain is not required for nitrogen fixation in mesophiles.
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Affiliation(s)
| | | | | | | | - Luis M. Rubio
- *Correspondence: Carlos Echavarri-Erasun, Luis M. Rubio,
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27
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Burén S, Young EM, Sweeny EA, Lopez-Torrejón G, Veldhuizen M, Voigt CA, Rubio LM. Formation of Nitrogenase NifDK Tetramers in the Mitochondria of Saccharomyces cerevisiae. ACS Synth Biol 2017; 6:1043-1055. [PMID: 28221768 PMCID: PMC5477005 DOI: 10.1021/acssynbio.6b00371] [Citation(s) in RCA: 47] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Transferring the prokaryotic enzyme nitrogenase into a eukaryotic host with the final aim of developing N2 fixing cereal crops would revolutionize agricultural systems worldwide. Targeting it to mitochondria has potential advantages because of the organelle's high O2 consumption and the presence of bacterial-type iron-sulfur cluster biosynthetic machinery. In this study, we constructed 96 strains of Saccharomyces cerevisiae in which transcriptional units comprising nine Azotobacter vinelandii nif genes (nifHDKUSMBEN) were integrated into the genome. Two combinatorial libraries of nif gene clusters were constructed: a library of mitochondrial leading sequences consisting of 24 clusters within four subsets of nif gene expression strength, and an expression library of 72 clusters with fixed mitochondrial leading sequences and nif expression levels assigned according to factorial design. In total, 29 promoters and 18 terminators were combined to adjust nif gene expression levels. Expression and mitochondrial targeting was confirmed at the protein level as immunoblot analysis showed that Nif proteins could be efficiently accumulated in mitochondria. NifDK tetramer formation, an essential step of nitrogenase assembly, was experimentally proven both in cell-free extracts and in purified NifDK preparations. This work represents a first step toward obtaining functional nitrogenase in the mitochondria of a eukaryotic cell.
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Affiliation(s)
- Stefan Burén
- Centro
de Biotecnología y Genómica de Plantas, Universidad Politécnica de Madrid (UPM) - Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria (INIA), Campus Montegancedo
UPM, 28223, Pozuelo
de Alarcón, Madrid, Spain
| | - Eric M. Young
- Synthetic
Biology Center, Department of Biological Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, United States
| | - Elizabeth A. Sweeny
- Synthetic
Biology Center, Department of Biological Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, United States
| | - Gema Lopez-Torrejón
- Centro
de Biotecnología y Genómica de Plantas, Universidad Politécnica de Madrid (UPM) - Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria (INIA), Campus Montegancedo
UPM, 28223, Pozuelo
de Alarcón, Madrid, Spain
| | - Marcel Veldhuizen
- Centro
de Biotecnología y Genómica de Plantas, Universidad Politécnica de Madrid (UPM) - Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria (INIA), Campus Montegancedo
UPM, 28223, Pozuelo
de Alarcón, Madrid, Spain
| | - Christopher A. Voigt
- Synthetic
Biology Center, Department of Biological Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, United States
| | - Luis M. Rubio
- Centro
de Biotecnología y Genómica de Plantas, Universidad Politécnica de Madrid (UPM) - Instituto Nacional de Investigación y Tecnología Agraria y Alimentaria (INIA), Campus Montegancedo
UPM, 28223, Pozuelo
de Alarcón, Madrid, Spain
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28
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Esteves-Ferreira AA, Cavalcanti JHF, Vaz MGMV, Alvarenga LV, Nunes-Nesi A, Araújo WL. Cyanobacterial nitrogenases: phylogenetic diversity, regulation and functional predictions. Genet Mol Biol 2017; 40:261-275. [PMID: 28323299 PMCID: PMC5452144 DOI: 10.1590/1678-4685-gmb-2016-0050] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/29/2016] [Accepted: 12/21/2016] [Indexed: 12/21/2022] Open
Abstract
Cyanobacteria is a remarkable group of prokaryotic photosynthetic microorganisms, with several genera capable of fixing atmospheric nitrogen (N2) and presenting a wide range of morphologies. Although the nitrogenase complex is not present in all cyanobacterial taxa, it is spread across several cyanobacterial strains. The nitrogenase complex has also a high theoretical potential for biofuel production, since H2 is a by-product produced during N2 fixation. In this review we discuss the significance of a relatively wide variety of cell morphologies and metabolic strategies that allow spatial and temporal separation of N2 fixation from photosynthesis in cyanobacteria. Phylogenetic reconstructions based on 16S rRNA and nifD gene sequences shed light on the evolutionary history of the two genes. Our results demonstrated that (i) sequences of genes involved in nitrogen fixation (nifD) from several morphologically distinct strains of cyanobacteria are grouped in similarity with their morphology classification and phylogeny, and (ii) nifD genes from heterocytous strains share a common ancestor. By using this data we also discuss the evolutionary importance of processes such as horizontal gene transfer and genetic duplication for nitrogenase evolution and diversification. Finally, we discuss the importance of H2 synthesis in cyanobacteria, as well as strategies and challenges to improve cyanobacterial H2 production.
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Affiliation(s)
- Alberto A Esteves-Ferreira
- Departamento de Biologia Vegetal, Universidade Federal de Viçosa, Viçosa, MG, Brazil.,Max-Planck-partner group at the Departamento de Biologia Vegetal, Universidade Federal de Viçosa, Viçosa, MG, Brazil
| | - João Henrique Frota Cavalcanti
- Departamento de Biologia Vegetal, Universidade Federal de Viçosa, Viçosa, MG, Brazil.,Max-Planck-partner group at the Departamento de Biologia Vegetal, Universidade Federal de Viçosa, Viçosa, MG, Brazil
| | - Marcelo Gomes Marçal Vieira Vaz
- Departamento de Biologia Vegetal, Universidade Federal de Viçosa, Viçosa, MG, Brazil.,Max-Planck-partner group at the Departamento de Biologia Vegetal, Universidade Federal de Viçosa, Viçosa, MG, Brazil
| | - Luna V Alvarenga
- Departamento de Biologia Vegetal, Universidade Federal de Viçosa, Viçosa, MG, Brazil.,Max-Planck-partner group at the Departamento de Biologia Vegetal, Universidade Federal de Viçosa, Viçosa, MG, Brazil
| | - Adriano Nunes-Nesi
- Departamento de Biologia Vegetal, Universidade Federal de Viçosa, Viçosa, MG, Brazil.,Max-Planck-partner group at the Departamento de Biologia Vegetal, Universidade Federal de Viçosa, Viçosa, MG, Brazil
| | - Wagner L Araújo
- Departamento de Biologia Vegetal, Universidade Federal de Viçosa, Viçosa, MG, Brazil.,Max-Planck-partner group at the Departamento de Biologia Vegetal, Universidade Federal de Viçosa, Viçosa, MG, Brazil
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29
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Role of the nifB1 and nifB2 Promoters in Cell-Type-Specific Expression of Two Mo Nitrogenases in the Cyanobacterium Anabaena variabilis ATCC 29413. J Bacteriol 2017; 199:JB.00674-16. [PMID: 27920300 DOI: 10.1128/jb.00674-16] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2016] [Accepted: 11/29/2016] [Indexed: 12/20/2022] Open
Abstract
Anabaena variabilis ATCC 29413 has one Mo nitrogenase that is made under oxic growth conditions in specialized cells called heterocysts and a second Mo nitrogenase that is made only under anoxic conditions in vegetative cells. The two large nif gene clusters responsible for these two nitrogenases are under the control of the promoter of the first gene in the operon, nifB1 or nifB2 Despite differences in the expression patterns of nifB1 and nifB2, related to oxygen and cell type, the regions upstream of their transcription start sites (tss) show striking homology, including three highly conserved sequences (CS). CS1, CS2, and the region just upstream from the tss were required for optimal expression from the nifB1 promoter, but CS3 and the 5' untranslated region (UTR) were not. Hybrid fusions of the nifB1 and nifB2 upstream regions revealed that the region including CS1, CS2, and CS3 of nifB2 could substitute for the similar region of nifB1; however, the converse was not true. Expression from the nifB2 promoter region required the CS1, CS2, and CS3 regions of nifB2 and also required the nifB2 5' UTR. A hybrid promoter that was mostly nifB2 but that had the region from about position -40 to the tss of nifB1 was expressed in heterocysts and in anoxic vegetative cells. Thus, addition of the nifB1 promoter region (from about position -40 to the tss of nifB1) in the nifB hybrid promoter supported expression in heterocysts but did not prevent the mostly nifB2 promoter from also functioning in anoxic vegetative cells. IMPORTANCE In the filamentous cyanobacterium Anabaena variabilis, two Mo nitrogenase gene clusters, nif1 and nif2, function under different environmental conditions in different cell types. Little is known about the regulation of transcription from the promoter upstream of the first gene of the cluster, which drives transcription of each of these two large operons. The similarity in the sequences upstream of the primary promoters for the two nif gene clusters belies the differences in their expression patterns. Analysis of these nif promoters in strains with mutations in the conserved sequences and in strains with hybrid promoters, comprising parts from nif1 and nif2, provides strong evidence that each promoter has key elements required for cell-type-specific expression of the nif1 and nif2 gene clusters.
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30
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Burén S, Jiang X, López-Torrejón G, Echavarri-Erasun C, Rubio LM. Purification and In Vitro Activity of Mitochondria Targeted Nitrogenase Cofactor Maturase NifB. FRONTIERS IN PLANT SCIENCE 2017; 8:1567. [PMID: 28955359 PMCID: PMC5601070 DOI: 10.3389/fpls.2017.01567] [Citation(s) in RCA: 36] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/31/2017] [Accepted: 08/28/2017] [Indexed: 05/13/2023]
Abstract
Active NifB is a milestone in the process of engineering nitrogen fixing plants. NifB is an extremely O2-sensitive S-adenosyl methionine (SAM)-radical enzyme that provides the key metal cluster intermediate (NifB-co) for the biosyntheses of the active-site cofactors of all three types of nitrogenases. NifB and NifB-co are unique to diazotrophic organisms. In this work, we have expressed synthetic codon-optimized versions of NifB from the γ-proteobacterium Azotobacter vinelandii and the thermophilic methanogen Methanocaldococcus infernus in Saccharomyces cerevisiae and in Nicotiana benthamiana. NifB proteins were targeted to the mitochondria, where O2 consumption is high and bacterial-like [Fe-S] cluster assembly operates. In yeast, NifB proteins were co-expressed with NifU, NifS, and FdxN proteins that are involved in NifB [Fe-S] cluster assembly and activity. The synthetic version of thermophilic NifB accumulated in soluble form within the yeast cell, while the A. vinelandii version appeared to form aggregates. Similarly, NifB from M. infernus was expressed at higher levels in leaves of Nicotiana benthamiana and accumulated as a soluble protein while A. vinelandii NifB was mainly associated with the non-soluble cell fraction. Soluble M. infernus NifB was purified from aerobically grown yeast and biochemically characterized. The purified protein was functional in the in vitro FeMo-co synthesis assay. This work presents the first active NifB protein purified from a eukaryotic cell, and highlights the importance of screening nif genes from different organisms in order to sort the best candidates to assemble a functional plant nitrogenase.
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Holm RH, Lo W. Structural Conversions of Synthetic and Protein-Bound Iron–Sulfur Clusters. Chem Rev 2016; 116:13685-13713. [DOI: 10.1021/acs.chemrev.6b00276] [Citation(s) in RCA: 83] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- R. H. Holm
- Department
of Chemistry and
Chemical Biology, Harvard University, Cambridge, Massachusetts 02138, United States
| | - Wayne Lo
- Department
of Chemistry and
Chemical Biology, Harvard University, Cambridge, Massachusetts 02138, United States
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33
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De Meyer SE, Briscoe L, Martínez-Hidalgo P, Agapakis CM, de-Los Santos PE, Seshadri R, Reeve W, Weinstock G, O'Hara G, Howieson JG, Hirsch AM. Symbiotic Burkholderia Species Show Diverse Arrangements of nif/fix and nod Genes and Lack Typical High-Affinity Cytochrome cbb3 Oxidase Genes. MOLECULAR PLANT-MICROBE INTERACTIONS : MPMI 2016; 29:609-619. [PMID: 27269511 DOI: 10.1094/mpmi-05-16-0091-r] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
Genome analysis of fourteen mimosoid and four papilionoid beta-rhizobia together with fourteen reference alpha-rhizobia for both nodulation (nod) and nitrogen-fixing (nif/fix) genes has shown phylogenetic congruence between 16S rRNA/MLSA (combined 16S rRNA gene sequencing and multilocus sequence analysis) and nif/fix genes, indicating a free-living diazotrophic ancestry of the beta-rhizobia. However, deeper genomic analysis revealed a complex symbiosis acquisition history in the beta-rhizobia that clearly separates the mimosoid and papilionoid nodulating groups. Mimosoid-nodulating beta-rhizobia have nod genes tightly clustered in the nodBCIJHASU operon, whereas papilionoid-nodulating Burkholderia have nodUSDABC and nodIJ genes, although their arrangement is not canonical because the nod genes are subdivided by the insertion of nif and other genes. Furthermore, the papilionoid Burkholderia spp. contain duplications of several nod and nif genes. The Burkholderia nifHDKEN and fixABC genes are very closely related to those found in free-living diazotrophs. In contrast, nifA is highly divergent between both groups, but the papilionoid species nifA is more similar to alpha-rhizobia nifA than to other groups. Surprisingly, for all Burkholderia, the fixNOQP and fixGHIS genes required for cbb3 cytochrome oxidase production and assembly are missing. In contrast, symbiotic Cupriavidus strains have fixNOQPGHIS genes, revealing a divergence in the evolution of two distinct electron transport chains required for nitrogen fixation within the beta-rhizobia.
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Affiliation(s)
- Sofie E De Meyer
- 1 Centre for Rhizobium Studies, Murdoch University, Western Australia, Australia
| | - Leah Briscoe
- 2 Dept. of Molecular, Cell and Developmental Biology, UCLA, Los Angeles, CA, U.S.A
| | | | - Christina M Agapakis
- 2 Dept. of Molecular, Cell and Developmental Biology, UCLA, Los Angeles, CA, U.S.A
| | - Paulina Estrada de-Los Santos
- 3 Instituto Politécnico Nacional, Escuela Nacional de Ciencias Biológicas. Prol. Carpio y Plan de Ayala s/n, Col. Santo Tomás, Del. Miguel Hidalgo, C.P. 11340, México
| | | | - Wayne Reeve
- 1 Centre for Rhizobium Studies, Murdoch University, Western Australia, Australia
| | - George Weinstock
- 5 The Jackson Laboratory for Genomic Medicine, Farmington, CT, U.S.A; and
| | - Graham O'Hara
- 1 Centre for Rhizobium Studies, Murdoch University, Western Australia, Australia
| | - John G Howieson
- 1 Centre for Rhizobium Studies, Murdoch University, Western Australia, Australia
| | - Ann M Hirsch
- 2 Dept. of Molecular, Cell and Developmental Biology, UCLA, Los Angeles, CA, U.S.A
- 6 The Molecular Biology Institute, UCLA, Los Angeles, CA, U.S.A
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Wilcoxen J, Arragain S, Scandurra AA, Jimenez-Vicente E, Echavarri-Erasun C, Pollmann S, Britt RD, Rubio LM. Electron Paramagnetic Resonance Characterization of Three Iron-Sulfur Clusters Present in the Nitrogenase Cofactor Maturase NifB from Methanocaldococcus infernus. J Am Chem Soc 2016; 138:7468-71. [PMID: 27268267 DOI: 10.1021/jacs.6b03329] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
NifB utilizes two equivalents of S-adenosyl methionine (SAM) to insert a carbide atom and fuse two substrate [Fe-S] clusters forming the NifB cofactor (NifB-co), which is then passed to NifEN for further modification to form the iron-molybdenum cofactor (FeMo-co) of nitrogenase. Here, we demonstrate that NifB from the methanogen Methanocaldococcus infernus is a radical SAM enzyme able to reductively cleave SAM to 5'-deoxyadenosine radical and is competent in FeMo-co maturation. Using electron paramagnetic resonance spectroscopy we have characterized three [4Fe-4S] clusters, one SAM binding cluster, and two auxiliary clusters probably acting as substrates for NifB-co formation. Nitrogen coordination to one or more of the auxiliary clusters in NifB was observed, and its mechanistic implications for NifB-co dissociation from the maturase are discussed.
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Affiliation(s)
- Jarett Wilcoxen
- Department of Chemistry, University of California , Davis, California 95616, United States
| | - Simon Arragain
- Centro de Biotecnología y Genómica de Plantas, Universidad Politécnica de Madrid , Pozuelo de Alarcón, Madrid 28223, Spain
| | - Alessandro A Scandurra
- Centro de Biotecnología y Genómica de Plantas, Universidad Politécnica de Madrid , Pozuelo de Alarcón, Madrid 28223, Spain
| | - Emilio Jimenez-Vicente
- Centro de Biotecnología y Genómica de Plantas, Universidad Politécnica de Madrid , Pozuelo de Alarcón, Madrid 28223, Spain
| | - Carlos Echavarri-Erasun
- Centro de Biotecnología y Genómica de Plantas, Universidad Politécnica de Madrid , Pozuelo de Alarcón, Madrid 28223, Spain
| | - Stephan Pollmann
- Centro de Biotecnología y Genómica de Plantas, Universidad Politécnica de Madrid , Pozuelo de Alarcón, Madrid 28223, Spain
| | - R David Britt
- Department of Chemistry, University of California , Davis, California 95616, United States
| | - Luis M Rubio
- Centro de Biotecnología y Genómica de Plantas, Universidad Politécnica de Madrid , Pozuelo de Alarcón, Madrid 28223, Spain
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Expression of a functional oxygen-labile nitrogenase component in the mitochondrial matrix of aerobically grown yeast. Nat Commun 2016; 7:11426. [PMID: 27126134 PMCID: PMC4855529 DOI: 10.1038/ncomms11426] [Citation(s) in RCA: 71] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2015] [Accepted: 03/23/2016] [Indexed: 11/08/2022] Open
Abstract
The extreme sensitivity of nitrogenase towards oxygen stands as a major barrier to engineer biological nitrogen fixation into cereal crops by direct nif gene transfer. Here, we use yeast as a model of eukaryotic cell and show that aerobically grown cells express active nitrogenase Fe protein when the NifH polypeptide is targeted to the mitochondrial matrix together with the NifM maturase. Co-expression of NifH and NifM with Nif-specific Fe-S cluster biosynthetic proteins NifU and NifS is not required for Fe protein activity, demonstrating NifH ability to incorporate endogenous mitochondrial Fe-S clusters. In contrast, expression of active Fe protein in the cytosol requires both anoxic growth conditions and co-expression of NifH and NifM with NifU and NifS. Our results show the convenience of using mitochondria to host nitrogenase components, thus providing instrumental technology for the grand challenge of engineering N2-fixing cereals.
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[NiFe]-hydrogenase maturation in vitro: analysis of the roles of the HybG and HypD accessory proteins1. Biochem J 2015; 464:169-77. [PMID: 25184670 DOI: 10.1042/bj20140485] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
[NiFe]-hydrogenases (Hyd) bind a nickel-iron-based cofactor. The Fe ion of the cofactor is bound by two cyanide ligands and a single carbon monoxide ligand. Minimally six accessory proteins (HypA-HypF) are necessary for NiFe(CN)2CO cofactor biosynthesis in Escherichia coli. It has been shown that the anaerobically purified HypC-HypD-HypE scaffold complex carries the Fe(CN)2CO moiety of this cofactor. In the present study, we have purified the HybG-HypDE complex and used it to successfully reconstitute in vitro active Hyd from E. coli. HybG is a homologue of HypC that is specifically required for the maturation of Hyd-2 and also functions in the maturation of Hyd-1 of E. coli. Maturation of active Hyd-1 and Hyd-2 could be demonstrated in extracts derived from HybG- and HypD-deficient E. coli strains by adding anaerobically purified HybG-HypDE complex. In vitro maturation was dependent on ATP, carbamoylphosphate, nickel and reducing conditions. Hydrogenase maturation was prevented when the purified HybG-HypDE complex used in the maturation assay lacked a bound Fe(CN)2CO moiety. These findings demonstrate that it is possible to isolate incompletely processed intermediates on the maturation pathway and to use these to activate apo-forms of [NiFe]-hydrogenase large subunits.
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Role of RNA secondary structure and processing in stability of the nifH1 transcript in the cyanobacterium Anabaena variabilis. J Bacteriol 2015; 197:1408-22. [PMID: 25666132 DOI: 10.1128/jb.02609-14] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
UNLABELLED In the cyanobacterium Anabaena variabilis ATCC 29413, aerobic nitrogen fixation occurs in micro-oxic cells called heterocysts. Synthesis of nitrogenase in heterocysts requires expression of the large nif1 gene cluster, which is primarily under the control of the promoter for the first gene, nifB1. Strong expression of nifH1 requires the nifB1 promoter but is also controlled by RNA processing, which leads to increased nifH1 transcript stability. The processing of the primary nifH1 transcript occurs at the base of a predicted stem-loop structure that is conserved in many heterocystous cyanobacteria. Mutations that changed the predicted secondary structure or changed the sequence of the stem-loop had detrimental effects on the amount of nifH1 transcript, with mutations that altered or destabilized the structure having the strongest effect. Just upstream from the transcriptional processing site for nifH1 was the promoter for a small antisense RNA, sava4870.1. This RNA was more strongly expressed in cells grown in the presence of fixed nitrogen and was downregulated in cells 24 h after nitrogen step down. A mutant strain lacking the promoter for sava4870.1 showed delayed nitrogen fixation; however, that phenotype might have resulted from an effect of the mutation on the processing of the nifH1 transcript. The nifH1 transcript was the most abundant and most stable nif1 transcript, while nifD1 and nifK1, just downstream of nifH1, were present in much smaller amounts and were less stable. The nifD1 and nifK1 transcripts were also processed at sites just upstream of nifD1 and nifK1. IMPORTANCE In the filamentous cyanobacterium Anabaena variabilis, the nif1 cluster, encoding the primary Mo nitrogenase, functions under aerobic growth conditions in specialized cells called heterocysts that develop in response to starvation for fixed nitrogen. The large cluster comprising more than a dozen nif1 genes is transcribed primarily from the promoter for the first gene, nifB1; however, this does not explain the large amount of transcript for the structural genes nifH1, nifD1, and nifK1, which are also under the control of the distant nifB1 promoter. Here, we demonstrate the importance of a predicted stem-loop structure upstream of nifH1 that controls the abundance of nifH1 transcript through transcript processing and stabilization and show that nifD1 and nifK1 transcripts are also controlled by transcript processing.
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Thiel T, Pratte BS. Regulation of Three Nitrogenase Gene Clusters in the Cyanobacterium Anabaena variabilis ATCC 29413. Life (Basel) 2014; 4:944-67. [PMID: 25513762 PMCID: PMC4284476 DOI: 10.3390/life4040944] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2014] [Revised: 11/21/2014] [Accepted: 12/04/2014] [Indexed: 11/16/2022] Open
Abstract
The filamentous cyanobacterium Anabaena variabilis ATCC 29413 fixes nitrogen under aerobic conditions in specialized cells called heterocysts that form in response to an environmental deficiency in combined nitrogen. Nitrogen fixation is mediated by the enzyme nitrogenase, which is very sensitive to oxygen. Heterocysts are microxic cells that allow nitrogenase to function in a filament comprised primarily of vegetative cells that produce oxygen by photosynthesis. A. variabilis is unique among well-characterized cyanobacteria in that it has three nitrogenase gene clusters that encode different nitrogenases, which function under different environmental conditions. The nif1 genes encode a Mo-nitrogenase that functions only in heterocysts, even in filaments grown anaerobically. The nif2 genes encode a different Mo-nitrogenase that functions in vegetative cells, but only in filaments grown under anoxic conditions. An alternative V-nitrogenase is encoded by vnf genes that are expressed only in heterocysts in an environment that is deficient in Mo. Thus, these three nitrogenases are expressed differentially in response to environmental conditions. The entire nif1 gene cluster, comprising at least 15 genes, is primarily under the control of the promoter for the first gene, nifB1. Transcriptional control of many of the downstream nif1 genes occurs by a combination of weak promoters within the coding regions of some downstream genes and by RNA processing, which is associated with increased transcript stability. The vnf genes show a similar pattern of transcriptional and post-transcriptional control of expression suggesting that the complex pattern of regulation of the nif1 cluster is conserved in other cyanobacterial nitrogenase gene clusters.
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Affiliation(s)
- Teresa Thiel
- Department of Biology, University of Missouri-St. Louis, St. Louis, MO 63121, USA.
| | - Brenda S Pratte
- Department of Biology, University of Missouri-St. Louis, St. Louis, MO 63121, USA.
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Reconstruction and minimal gene requirements for the alternative iron-only nitrogenase in Escherichia coli. Proc Natl Acad Sci U S A 2014; 111:E3718-25. [PMID: 25139995 DOI: 10.1073/pnas.1411185111] [Citation(s) in RCA: 64] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
All diazotrophic organisms sequenced to date encode a molybdenum-dependent nitrogenase, but some also have alternative nitrogenases that are dependent on either vanadium (VFe) or iron only (FeFe) for activity. In Azotobacter vinelandii, expression of the three different types of nitrogenase is regulated in response to metal availability. The majority of genes required for nitrogen fixation in this organism are encoded in the nitrogen fixation (nif) gene clusters, whereas genes specific for vanadium- or iron-dependent diazotophy are encoded by the vanadium nitrogen fixation (vnf) and alternative nitrogen fixation (anf) genes, respectively. Due to the complexities of metal-dependent regulation and gene redundancy in A. vinelandii, it has been difficult to determine the precise genetic requirements for alternative nitrogen fixation. In this study, we have used Escherichia coli as a chassis to build an artificial iron-only (Anf) nitrogenase system composed of defined anf and nif genes. Using this system, we demonstrate that the pathway for biosynthesis of the iron-only cofactor (FeFe-co) is likely to be simpler than the pathway for biosynthesis of the molybdenum-dependent cofactor (FeMo-co) equivalent. A number of genes considered to be essential for nitrogen fixation by FeFe nitrogenase, including nifM, vnfEN, and anfOR, are not required for the artificial Anf system in E. coli. This finding has enabled us to engineer a minimal FeFe nitrogenase system comprising the structural anfHDGK genes and the nifBUSV genes required for metallocluster biosynthesis, with nifF and nifJ providing electron transport to the alternative nitrogenase. This minimal Anf system has potential implications for engineering diazotrophy in eukaryotes, particularly in compartments (e.g., organelles) where molybdenum may be limiting.
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Curatti L, Rubio LM. Challenges to develop nitrogen-fixing cereals by direct nif-gene transfer. PLANT SCIENCE : AN INTERNATIONAL JOURNAL OF EXPERIMENTAL PLANT BIOLOGY 2014; 225:130-7. [PMID: 25017168 DOI: 10.1016/j.plantsci.2014.06.003] [Citation(s) in RCA: 66] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/25/2014] [Revised: 05/24/2014] [Accepted: 06/03/2014] [Indexed: 05/19/2023]
Abstract
Some regions of the developing world suffer low cereal production yields due to low fertilizer inputs, among other factors. Biological N2 fixation, catalyzed by the prokaryotic enzyme nitrogenase, is an alternative to the use of synthetic N fertilizers. The molybdenum nitrogenase is an O2-labile metalloenzyme composed of the NifDK and NifH proteins, which biosyntheses require a number of nif gene products. A challenging strategy to increase cereal crop productivity in a scenario of low N fertilization is the direct transfer of nif genes into cereals. The sensitivity of nitrogenase to O2 and the apparent complexity of nitrogenase biosynthesis are the main barriers identified so far. Expression of active NifH requires the products of nifM, nifH, and possibly nifU and nifS, whereas active NifDK requires the products of nifH, nifD, nifK, nifB, nifE, nifN, and possibly nifU, nifS, nifQ, nifV, nafY, nifW and nifZ. Plastids and mitochondria are potential subcellular locations for nitrogenase. Both could provide the ATP and electrons required for nitrogenase to function but they differ in their internal O2 levels and their ability to incorporate ammonium into amino acids.
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Affiliation(s)
- Leonardo Curatti
- Instituto de Investigaciones en Biodiversidad y Biotecnología - Consejo Nacional de Investigaciones Científicas y Técnicas, Mar del Plata, Buenos Aires, Argentina; Fundación para Investigaciones Biológicas Aplicadas, Pozuelo de Alarcón, Madrid, Spain
| | - Luis M Rubio
- Centro de Biotecnología y Genómica de Plantas, Universidad Politécnica de Madrid, Pozuelo de Alarcón, Madrid, Spain.
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Broderick JB, Duffus B, Duschene KS, Shepard EM. Radical S-adenosylmethionine enzymes. Chem Rev 2014; 114:4229-317. [PMID: 24476342 PMCID: PMC4002137 DOI: 10.1021/cr4004709] [Citation(s) in RCA: 589] [Impact Index Per Article: 58.9] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2013] [Indexed: 12/22/2022]
Affiliation(s)
- Joan B. Broderick
- Department of Chemistry and
Biochemistry, Montana State University, Bozeman, Montana 59717, United States
| | - Benjamin
R. Duffus
- Department of Chemistry and
Biochemistry, Montana State University, Bozeman, Montana 59717, United States
| | - Kaitlin S. Duschene
- Department of Chemistry and
Biochemistry, Montana State University, Bozeman, Montana 59717, United States
| | - Eric M. Shepard
- Department of Chemistry and
Biochemistry, Montana State University, Bozeman, Montana 59717, United States
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Happe T, Hemschemeier A. Metalloprotein mimics – old tools in a new light. Trends Biotechnol 2014; 32:170-6. [DOI: 10.1016/j.tibtech.2014.02.004] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2013] [Revised: 02/07/2014] [Accepted: 02/07/2014] [Indexed: 01/03/2023]
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Kuchenreuther JM, Shiigi SA, Swartz JR. Cell-free synthesis of the H-cluster: a model for the in vitro assembly of metalloprotein metal centers. Methods Mol Biol 2014; 1122:49-72. [PMID: 24639253 DOI: 10.1007/978-1-62703-794-5_5] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Many organometallic cofactors are highly complex and require multiple accessory proteins for both their assembly and transfer to a target protein. A cell-free system in which the biosynthetic pathway for a prosthetic group has been fully or even partially reconstructed enables investigations of the reaction sequence as well as the cofactor itself. As a model for the in vitro assembly of protein-bound metal centers, we describe a procedure for the cell-free synthesis of the H-cluster in the context of producing purified and active [FeFe] hydrogenase samples for spectroscopic studies. In general terms, this in vitro system is a combination of non-purified accessory proteins, exogenous substrates, and purified hydrogenase apoprotein. We also describe methods for making the required components used in the cell-free system. Specifically, these procedures include anaerobic expression of heterologous metalloproteins in Escherichia coli, anaerobic cell lysate production, and anaerobic metalloprotein purification using Strep-Tactin(®) chromatography.
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Affiliation(s)
- Jon M Kuchenreuther
- Department of Chemical Engineering, Stanford University, 381 North South Mall, Stanford, CA, 94305-5025, USA,
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Wang L, Zhang L, Liu Z, Zhao D, Liu X, Zhang B, Xie J, Hong Y, Li P, Chen S, Dixon R, Li J. A minimal nitrogen fixation gene cluster from Paenibacillus sp. WLY78 enables expression of active nitrogenase in Escherichia coli. PLoS Genet 2013; 9:e1003865. [PMID: 24146630 PMCID: PMC3798268 DOI: 10.1371/journal.pgen.1003865] [Citation(s) in RCA: 92] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2013] [Accepted: 08/21/2013] [Indexed: 11/23/2022] Open
Abstract
Most biological nitrogen fixation is catalyzed by molybdenum-dependent nitrogenase, an enzyme complex comprising two component proteins that contains three different metalloclusters. Diazotrophs contain a common core of nitrogen fixation nif genes that encode the structural subunits of the enzyme and components required to synthesize the metalloclusters. However, the complement of nif genes required to enable diazotrophic growth varies significantly amongst nitrogen fixing bacteria and archaea. In this study, we identified a minimal nif gene cluster consisting of nine nif genes in the genome of Paenibacillus sp. WLY78, a gram-positive, facultative anaerobe isolated from the rhizosphere of bamboo. We demonstrate that the nif genes in this organism are organized as an operon comprising nifB, nifH, nifD, nifK, nifE, nifN, nifX, hesA and nifV and that the nif cluster is under the control of a σ70 (σA)-dependent promoter located upstream of nifB. To investigate genetic requirements for diazotrophy, we transferred the Paenibacillus nif cluster to Escherichia coli. The minimal nif gene cluster enables synthesis of catalytically active nitrogenase in this host, when expressed either from the native nifB promoter or from the T7 promoter. Deletion analysis indicates that in addition to the core nif genes, hesA plays an important role in nitrogen fixation and is responsive to the availability of molybdenum. Whereas nif transcription in Paenibacillus is regulated in response to nitrogen availability and by the external oxygen concentration, transcription from the nifB promoter is constitutive in E. coli, indicating that negative regulation of nif transcription is bypassed in the heterologous host. This study demonstrates the potential for engineering nitrogen fixation in a non-nitrogen fixing organism with a minimum set of nine nif genes. Biological nitrogen fixation plays an essential role in the nitrogen cycle, sustaining agricultural productivity by providing a source of fixed nitrogen for plants and ultimately animals. The enzyme nitrogenase that catalyses the reduction of atmospheric dinitrogen to ammonia contains one of the most complex heterometal cofactors found in biology. Biosynthesis of nitrogenase and provision of support for its activity requires a large number of nitrogen fixation (nif) genes, which vary according to the physiological lifestyle of the host organism. In this study, we identified a nif cluster with reduced genetic complexity, consisting of nine genes organized as a single operon in the genome of Paenibacillus sp. WLY78. When transferred to Escherichia coli, the Paenibacllus nif cluster enables synthesis of catalytically active nitrogenase, which is competent to reduce both acetylene and dinitrogen as substrates of the enzyme. Environmental regulation of nif gene expression in Paenibacillus, in response to either oxygen or fixed nitrogen, is circumvented when the nif operon is expressed from its native promoter in E. coli, suggesting that nif transcription in Paenibacillus is negatively regulated in response to these effectors.
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Affiliation(s)
- Liying Wang
- State Key Laboratory for Agrobiotechnology and College of Biological Sciences, China Agricultural University, Beijing, P. R. China
| | - Lihong Zhang
- State Key Laboratory for Agrobiotechnology and College of Biological Sciences, China Agricultural University, Beijing, P. R. China
- College of Life Science, Shanxi Normal University, Linfen, P. R. China
| | - Zhangzhi Liu
- State Key Laboratory for Agrobiotechnology and College of Biological Sciences, China Agricultural University, Beijing, P. R. China
| | - Dehua Zhao
- Synthetic Biology Center, Department of Biological Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts, United States of America
| | - Xiaomeng Liu
- State Key Laboratory for Agrobiotechnology and College of Biological Sciences, China Agricultural University, Beijing, P. R. China
| | - Bo Zhang
- State Key Laboratory for Agrobiotechnology and College of Biological Sciences, China Agricultural University, Beijing, P. R. China
| | - Jianbo Xie
- State Key Laboratory for Agrobiotechnology and College of Biological Sciences, China Agricultural University, Beijing, P. R. China
| | - Yuanyuan Hong
- State Key Laboratory for Agrobiotechnology and College of Biological Sciences, China Agricultural University, Beijing, P. R. China
| | - Pengfei Li
- State Key Laboratory for Agrobiotechnology and College of Biological Sciences, China Agricultural University, Beijing, P. R. China
| | - Sanfeng Chen
- State Key Laboratory for Agrobiotechnology and College of Biological Sciences, China Agricultural University, Beijing, P. R. China
- * E-mail: (SC); (RD)
| | - Ray Dixon
- Department of Molecular Microbiology, John Innes Centre, Norwich, United Kingdom
- * E-mail: (SC); (RD)
| | - Jilun Li
- State Key Laboratory for Agrobiotechnology and College of Biological Sciences, China Agricultural University, Beijing, P. R. China
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Wang X, Yang JG, Chen L, Wang JL, Cheng Q, Dixon R, Wang YP. Using synthetic biology to distinguish and overcome regulatory and functional barriers related to nitrogen fixation. PLoS One 2013; 8:e68677. [PMID: 23935879 PMCID: PMC3723869 DOI: 10.1371/journal.pone.0068677] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2013] [Accepted: 06/07/2013] [Indexed: 01/14/2023] Open
Abstract
Biological nitrogen fixation is a complex process requiring multiple genes working in concert. To date, the Klebsiella pneumoniae nif gene cluster, divided into seven operons, is one of the most studied systems. Its nitrogen fixation capacity is subject to complex cascade regulation and physiological limitations. In this report, the entire K. pneumoniae nif gene cluster was reassembled as operon-based BioBrick parts in Escherichia coli. It provided ~100% activity of native K. pneumoniae system. Based on the expression levels of these BioBrick parts, a T7 RNA polymerase-LacI expression system was used to replace the σ(54)-dependent promoters located upstream of nif operons. Expression patterns of nif operons were critical for the maximum activity of the recombinant system. By mimicking these expression levels with variable-strength T7-dependent promoters, ~42% of the nitrogenase activity of the σ(54)-dependent nif system was achieved in E. coli. When the newly constructed T7-dependent nif system was challenged with different genetic and physiological conditions, it bypassed the original complex regulatory circuits, with minor physiological limitations. Therefore, we have successfully replaced the nif regulatory elements with a simple expression system that may provide the first step for further research of introducing nif genes into eukaryotic organelles, which has considerable potentials in agro-biotechnology.
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Affiliation(s)
- Xia Wang
- State Key Laboratory of Protein and Plant Gene Research, College of Life Sciences, Peking University, Beijing, China
| | - Jian-Guo Yang
- State Key Laboratory of Protein and Plant Gene Research, College of Life Sciences, Peking University, Beijing, China
| | - Li Chen
- State Key Laboratory of Protein and Plant Gene Research, College of Life Sciences, Peking University, Beijing, China
| | - Ji-Long Wang
- State Key Laboratory of Protein and Plant Gene Research, College of Life Sciences, Peking University, Beijing, China
| | - Qi Cheng
- Biotechnology Research Institute, Chinese Academy of Agriculture Science, Beijing, China
| | - Ray Dixon
- Department of Molecular Microbiology, John Innes Centre, Norwich Research Park, Norwich, United Kingdom
- * E-mail: (RD); (YPW)
| | - Yi-Ping Wang
- State Key Laboratory of Protein and Plant Gene Research, College of Life Sciences, Peking University, Beijing, China
- * E-mail: (RD); (YPW)
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Singh M, Sharma NK, Prasad SB, Yadav SS, Narayan G, Rai AK. The freshwater cyanobacterium Anabaena doliolum transformed with ApGSMT-DMT exhibited enhanced salt tolerance and protection to nitrogenase activity, but became halophilic. Microbiology (Reading) 2013; 159:641-648. [DOI: 10.1099/mic.0.065078-0] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Affiliation(s)
- Meenakshi Singh
- Department of Botany, Banaras Hindu University, Varanasi 221 005, India
| | - Naveen K. Sharma
- Department of Botany, Indira Gandhi National Tribal University, Amarkantak, (M.P.) 484886, India
| | - Shyam Babu Prasad
- Department of Molecular and Human Genetics, Banaras Hindu University, Varanasi 221 005, India
| | - Suresh Singh Yadav
- Department of Molecular and Human Genetics, Banaras Hindu University, Varanasi 221 005, India
| | - Gopeshwar Narayan
- Department of Molecular and Human Genetics, Banaras Hindu University, Varanasi 221 005, India
| | - Ashwani K. Rai
- Department of Botany, Banaras Hindu University, Varanasi 221 005, India
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Kuchenreuther JM, Britt RD, Swartz JR. New insights into [FeFe] hydrogenase activation and maturase function. PLoS One 2012; 7:e45850. [PMID: 23049878 PMCID: PMC3457958 DOI: 10.1371/journal.pone.0045850] [Citation(s) in RCA: 59] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2012] [Accepted: 08/23/2012] [Indexed: 11/18/2022] Open
Abstract
[FeFe] hydrogenases catalyze H(2) production using the H-cluster, an iron-sulfur cofactor that contains carbon monoxide (CO), cyanide (CN(-)), and a dithiolate bridging ligand. The HydE, HydF, and HydG maturases assist in assembling the H-cluster and maturing hydrogenases into their catalytically active form. Characterization of these maturases and in vitro hydrogenase activation methods have helped elucidate steps in the H-cluster biosynthetic pathway such as the HydG-catalyzed generation of the CO and CN(-) ligands from free tyrosine. We have refined our cell-free approach for H-cluster synthesis and hydrogenase maturation by using separately expressed and purified HydE, HydF, and HydG. In this report, we illustrate how substrates and protein constituents influence hydrogenase activation, and for the first time, we show that each maturase can function catalytically during the maturation process. With precise control over the biomolecular components, we also provide evidence for H-cluster synthesis in the absence of either HydE or HydF, and we further show that hydrogenase activation can occur without exogenous tyrosine. Given these findings, we suggest a new reaction sequence for the [FeFe] hydrogenase maturation pathway. In our model, HydG independently synthesizes an iron-based compound with CO and CN(-) ligands that is a precursor to the H-cluster [2Fe](H) subunit, and which we have termed HydG-co. We further propose that HydF is a transferase that stabilizes HydG-co and also shuttles the complete [2Fe](H) subcluster to the hydrogenase, a translocation process that may be catalyzed by HydE. In summary, this report describes the first example of reconstructing the [FeFe] hydrogenase maturation pathway using purified maturases and subsequently utilizing this in vitro system to better understand the roles of HydE, HydF, and HydG.
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Affiliation(s)
- Jon M Kuchenreuther
- Department of Chemical Engineering, Stanford University, Stanford, California, USA
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Peters JW, Broderick JB. Emerging paradigms for complex iron-sulfur cofactor assembly and insertion. Annu Rev Biochem 2012; 81:429-50. [PMID: 22482905 DOI: 10.1146/annurev-biochem-052610-094911] [Citation(s) in RCA: 73] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
[FeFe]-hydrogenses and molybdenum (Mo)-nitrogenase are evolutionarily unrelated enzymes with unique complex iron-sulfur cofactors at their active sites. The H cluster of [FeFe]-hydrogenases and the FeMo cofactor of Mo-nitrogenase require specific maturation machinery for their proper synthesis and insertion into the structural enzymes. Recent insights reveal striking similarities in the biosynthetic pathways of these complex cofactors. For both systems, simple iron-sulfur cluster precursors are modified on assembly scaffolds by the activity of radical S-adenosylmethionine (SAM) enzymes. Radical SAM enzymes are responsible for the synthesis and insertion of the unique nonprotein ligands presumed to be key structural determinants for their respective catalytic activities. Maturation culminates in the transfer of the intact cluster assemblies to a cofactor-less structural protein recipient. Required roles for nucleotide binding and hydrolysis have been implicated in both systems, but the specific role for these requirements remain unclear. In this review, we highlight the progress on [FeFe]-hydrogenase H cluster and nitrogenase FeMo-cofactor assembly in the context of these emerging paradigms.
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Affiliation(s)
- John W Peters
- Department of Chemistry and Biochemistry and the Astrobiology Biogeocatalysis Research Center, Montana State University, Bozeman, Montana 59717, USA.
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Buchko GW, Robinson H. Crystal structure of cce_0566 from Cyanothece 51142, a protein associated with nitrogen fixation in the DUF269 family. FEBS Lett 2012; 586:350-5. [PMID: 22289180 PMCID: PMC3641832 DOI: 10.1016/j.febslet.2012.01.037] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2012] [Revised: 01/16/2012] [Accepted: 01/16/2012] [Indexed: 11/24/2022]
Abstract
The crystal structure for cce_0566 (171 aa, 19.4 kDa), a DUF269 annotated protein from the diazotrophic cyanobacterium Cyanothece sp. ATCC 51142, was determined to 1.60Å resolution. Cce_0566 is a homodimer with each molecule composed of eight α-helices folded on one side of a three strand anti-parallel β-sheet. Hydrophobic interactions between the side chains of largely conserved residues on the surface of each β-sheet hold the dimer together. The fold observed for cce_0566 may be unique to proteins in the DUF269 family, hence, the protein may also have a function unique to nitrogen fixation. A solvent accessible cleft containing conserved charged residues near the dimer interface could represent the active site or ligand-binding surface for the protein's biological function.
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Affiliation(s)
- Garry W Buchko
- Biological Sciences Division, Pacific Northwest National Laboratory, Richland, WA 99352, USA.
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Affiliation(s)
- Perrin H Beatty
- Department of Biological Sciences, University of Alberta, Edmonton, AB, Canada, T6G 2E9
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