1
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Sutter M, Kerfeld CA, Scott KM. Corrigendum: Atypical carboxysome loci: JEEPs or junk? Front Microbiol 2024; 15:1393362. [PMID: 38650886 PMCID: PMC11034363 DOI: 10.3389/fmicb.2024.1393362] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2024] [Accepted: 03/21/2024] [Indexed: 04/25/2024] Open
Abstract
[This corrects the article DOI: 10.3389/fmicb.2022.872708.].
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Affiliation(s)
| | | | - Markus Sutter
- MSU-DOE Plant Research Laboratory, Michigan State University, East Lansing, MI, United States
- Environmental Genomics and Systems Biology and Molecular Biophysics and Integrated Bioimaging Divisions, Lawrence Berkeley National Laboratory, Berkeley, CA, United States
| | - Cheryl A. Kerfeld
- MSU-DOE Plant Research Laboratory, Michigan State University, East Lansing, MI, United States
- Environmental Genomics and Systems Biology and Molecular Biophysics and Integrated Bioimaging Divisions, Lawrence Berkeley National Laboratory, Berkeley, CA, United States
| | - Kathleen M. Scott
- Integrative Biology Department, University of South Florida, Tampa, FL, United States
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2
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Vincent M, Blanc-Garin V, Chenebault C, Cirimele M, Farci S, Garcia-Alles LF, Cassier-Chauvat C, Chauvat F. Impact of Carbon Fixation, Distribution and Storage on the Production of Farnesene and Limonene in Synechocystis PCC 6803 and Synechococcus PCC 7002. Int J Mol Sci 2024; 25:3827. [PMID: 38612633 PMCID: PMC11012175 DOI: 10.3390/ijms25073827] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2024] [Revised: 03/04/2024] [Accepted: 03/27/2024] [Indexed: 04/14/2024] Open
Abstract
Terpenes are high-value chemicals which can be produced by engineered cyanobacteria from sustainable resources, solar energy, water and CO2. We previously reported that the euryhaline unicellular cyanobacteria Synechocystis sp. PCC 6803 (S.6803) and Synechococcus sp. PCC 7002 (S.7002) produce farnesene and limonene, respectively, more efficiently than other terpenes. In the present study, we attempted to enhance farnesene production in S.6803 and limonene production in S.7002. Practically, we tested the influence of key cyanobacterial enzymes acting in carbon fixation (RubisCO, PRK, CcmK3 and CcmK4), utilization (CrtE, CrtR and CruF) and storage (PhaA and PhaB) on terpene production in S.6803, and we compared some of the findings with the data obtained in S.7002. We report that the overproduction of RubisCO from S.7002 and PRK from Cyanothece sp. PCC 7425 increased farnesene production in S.6803, but not limonene production in S.7002. The overexpression of the crtE genes (synthesis of terpene precursors) from S.6803 or S.7002 did not increase farnesene production in S.6803. In contrast, the overexpression of the crtE gene from S.6803, but not S.7002, increased farnesene production in S.7002, emphasizing the physiological difference between these two model cyanobacteria. Furthermore, the deletion of the crtR and cruF genes (carotenoid synthesis) and phaAB genes (carbon storage) did not increase the production of farnesene in S.6803. Finally, as a containment strategy of genetically modified strains of S.6803, we report that the deletion of the ccmK3K4 genes (carboxysome for CO2 fixation) did not affect the production of limonene, but decreased the production of farnesene in S.6803.
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Affiliation(s)
- Marine Vincent
- Institute for Integrative Biology of the Cell (I2BC), Université Paris-Saclay, CEA, CNRS, 91198 Gif-sur-Yvette, France; (M.V.); (V.B.-G.); (C.C.); (M.C.); (S.F.); (C.C.-C.)
| | - Victoire Blanc-Garin
- Institute for Integrative Biology of the Cell (I2BC), Université Paris-Saclay, CEA, CNRS, 91198 Gif-sur-Yvette, France; (M.V.); (V.B.-G.); (C.C.); (M.C.); (S.F.); (C.C.-C.)
| | - Célia Chenebault
- Institute for Integrative Biology of the Cell (I2BC), Université Paris-Saclay, CEA, CNRS, 91198 Gif-sur-Yvette, France; (M.V.); (V.B.-G.); (C.C.); (M.C.); (S.F.); (C.C.-C.)
| | - Mattia Cirimele
- Institute for Integrative Biology of the Cell (I2BC), Université Paris-Saclay, CEA, CNRS, 91198 Gif-sur-Yvette, France; (M.V.); (V.B.-G.); (C.C.); (M.C.); (S.F.); (C.C.-C.)
- Université Paris-Saclay, ENS Paris-Saclay, 91190 Gif-sur-Yvette, France
| | - Sandrine Farci
- Institute for Integrative Biology of the Cell (I2BC), Université Paris-Saclay, CEA, CNRS, 91198 Gif-sur-Yvette, France; (M.V.); (V.B.-G.); (C.C.); (M.C.); (S.F.); (C.C.-C.)
| | - Luis Fernando Garcia-Alles
- Toulouse Biotechnology Institute, Université de Toulouse, CNRS, INRAE, INSA, 135 Avenue de Rangueil, 31077 Toulouse, France;
| | - Corinne Cassier-Chauvat
- Institute for Integrative Biology of the Cell (I2BC), Université Paris-Saclay, CEA, CNRS, 91198 Gif-sur-Yvette, France; (M.V.); (V.B.-G.); (C.C.); (M.C.); (S.F.); (C.C.-C.)
| | - Franck Chauvat
- Institute for Integrative Biology of the Cell (I2BC), Université Paris-Saclay, CEA, CNRS, 91198 Gif-sur-Yvette, France; (M.V.); (V.B.-G.); (C.C.); (M.C.); (S.F.); (C.C.-C.)
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3
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Li T, Chang P, Chen W, Shi Z, Xue C, Dykes GF, Huang F, Wang Q, Liu LN. Nanoengineering Carboxysome Shells for Protein Cages with Programmable Cargo Targeting. ACS Nano 2024; 18:7473-7484. [PMID: 38326220 PMCID: PMC10938918 DOI: 10.1021/acsnano.3c11559] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/20/2023] [Revised: 01/31/2024] [Accepted: 02/02/2024] [Indexed: 02/09/2024]
Abstract
Protein nanocages have emerged as promising candidates for enzyme immobilization and cargo delivery in biotechnology and nanotechnology. Carboxysomes are natural proteinaceous organelles in cyanobacteria and proteobacteria and have exhibited great potential in creating versatile nanocages for a wide range of applications given their intrinsic characteristics of self-assembly, cargo encapsulation, permeability, and modularity. However, how to program intact carboxysome shells with specific docking sites for tunable and efficient cargo loading is a key question in the rational design and engineering of carboxysome-based nanostructures. Here, we generate a range of synthetically engineered nanocages with site-directed cargo loading based on an α-carboxysome shell in conjunction with SpyTag/SpyCatcher and Coiled-coil protein coupling systems. The systematic analysis demonstrates that the cargo-docking sites and capacities of the carboxysome shell-based protein nanocages could be precisely modulated by selecting specific anchoring systems and shell protein domains. Our study provides insights into the encapsulation principles of the α-carboxysome and establishes a solid foundation for the bioengineering and manipulation of nanostructures capable of capturing cargos and molecules with exceptional efficiency and programmability, thereby enabling applications in catalysis, delivery, and medicine.
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Affiliation(s)
- Tianpei Li
- State
Key Laboratory of Crop Stress Adaptation and Improvement, School of
Life Sciences, Henan University, Kaifeng 475004, China
- Institute
of Systems, Molecular and Integrative Biology, University of Liverpool, Liverpool L69 7ZB, United
Kingdom
| | - Ping Chang
- Institute
of Systems, Molecular and Integrative Biology, University of Liverpool, Liverpool L69 7ZB, United
Kingdom
| | - Weixian Chen
- State
Key Laboratory of Crop Stress Adaptation and Improvement, School of
Life Sciences, Henan University, Kaifeng 475004, China
| | - Zhaoyang Shi
- State
Key Laboratory of Crop Stress Adaptation and Improvement, School of
Life Sciences, Henan University, Kaifeng 475004, China
| | - Chunling Xue
- State
Key Laboratory of Crop Stress Adaptation and Improvement, School of
Life Sciences, Henan University, Kaifeng 475004, China
| | - Gregory F. Dykes
- Institute
of Systems, Molecular and Integrative Biology, University of Liverpool, Liverpool L69 7ZB, United
Kingdom
| | - Fang Huang
- Institute
of Systems, Molecular and Integrative Biology, University of Liverpool, Liverpool L69 7ZB, United
Kingdom
| | - Qiang Wang
- State
Key Laboratory of Crop Stress Adaptation and Improvement, School of
Life Sciences, Henan University, Kaifeng 475004, China
| | - Lu-Ning Liu
- Institute
of Systems, Molecular and Integrative Biology, University of Liverpool, Liverpool L69 7ZB, United
Kingdom
- MOE
Key Laboratory of Evolution and Marine Biodiversity, Frontiers Science
Center for Deep Ocean Multispheres and Earth System & College
of Marine Life Sciences, Ocean University
of China, Qingdao 266003, China
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4
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Trettel DS, Pacheco SL, Laskie AK, Gonzalez-Esquer CR. Modeling bacterial microcompartment architectures for enhanced cyanobacterial carbon fixation. Front Plant Sci 2024; 15:1346759. [PMID: 38425792 PMCID: PMC10902431 DOI: 10.3389/fpls.2024.1346759] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/29/2023] [Accepted: 01/30/2024] [Indexed: 03/02/2024]
Abstract
The carboxysome is a bacterial microcompartment (BMC) which plays a central role in the cyanobacterial CO2-concentrating mechanism. These proteinaceous structures consist of an outer protein shell that partitions Rubisco and carbonic anhydrase from the rest of the cytosol, thereby providing a favorable microenvironment that enhances carbon fixation. The modular nature of carboxysomal architectures makes them attractive for a variety of biotechnological applications such as carbon capture and utilization. In silico approaches, such as molecular dynamics (MD) simulations, can support future carboxysome redesign efforts by providing new spatio-temporal insights on their structure and function beyond in vivo experimental limitations. However, specific computational studies on carboxysomes are limited. Fortunately, all BMC (including the carboxysome) are highly structurally conserved which allows for practical inferences to be made between classes. Here, we review simulations on BMC architectures which shed light on (1) permeation events through the shell and (2) assembly pathways. These models predict the biophysical properties surrounding the central pore in BMC-H shell subunits, which in turn dictate the efficiency of substrate diffusion. Meanwhile, simulations on BMC assembly demonstrate that assembly pathway is largely dictated kinetically by cargo interactions while final morphology is dependent on shell factors. Overall, these findings are contextualized within the wider experimental BMC literature and framed within the opportunities for carboxysome redesign for biomanufacturing and enhanced carbon fixation.
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Affiliation(s)
- Daniel S. Trettel
- Los Alamos National Laboratory, Bioscience Division, Microbial and Biome Sciences Group, Los Alamos, NM, United States
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5
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Nguyen ND, Pulsford SB, Förster B, Rottet S, Rourke L, Long BM, Price GD. A carboxysome-based CO 2 concentrating mechanism for C 3 crop chloroplasts: advances and the road ahead. Plant J 2024. [PMID: 38321620 DOI: 10.1111/tpj.16667] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/23/2023] [Revised: 01/17/2024] [Accepted: 01/24/2024] [Indexed: 02/08/2024]
Abstract
The introduction of the carboxysome-based CO2 concentrating mechanism (CCM) into crop plants has been modelled to significantly increase crop yields. This projection serves as motivation for pursuing this strategy to contribute to global food security. The successful implementation of this engineering challenge is reliant upon the transfer of a microcompartment that encapsulates cyanobacterial Rubisco, known as the carboxysome, alongside active bicarbonate transporters. To date, significant progress has been achieved with respect to understanding various aspects of the cyanobacterial CCM, and more recently, different components of the carboxysome have been successfully introduced into plant chloroplasts. In this Perspective piece, we summarise recent findings and offer new research avenues that will accelerate research in this field to ultimately and successfully introduce the carboxysome into crop plants for increased crop yields.
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Affiliation(s)
- Nghiem D Nguyen
- Plant Science Division, Research School of Biology, Australian National University, 134 Linnaeus Way, Acton, Australian Capital Territory, 2601, Australia
| | - Sacha B Pulsford
- Research School of Chemistry, Australian National University, 137 Sullivan's Ck Rd, Acton, Australian Capital Territory, 2601, Australia
| | - Britta Förster
- Plant Science Division, Research School of Biology, Australian National University, 134 Linnaeus Way, Acton, Australian Capital Territory, 2601, Australia
| | - Sarah Rottet
- Plant Science Division, Research School of Biology, Australian National University, 134 Linnaeus Way, Acton, Australian Capital Territory, 2601, Australia
| | - Loraine Rourke
- Plant Science Division, Research School of Biology, Australian National University, 134 Linnaeus Way, Acton, Australian Capital Territory, 2601, Australia
| | - Benedict M Long
- Discipline of Biological Sciences, School of Environmental and Life Sciences, ARC Centre of Excellence in Synthetic Biology, The University of Newcastle, University Drive, Callaghan, New South Wales, 2308, Australia
| | - G Dean Price
- Plant Science Division, Research School of Biology, Australian National University, 134 Linnaeus Way, Acton, Australian Capital Territory, 2601, Australia
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6
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Blikstad C, Dugan EJ, Laughlin TG, Turnšek JB, Liu MD, Shoemaker SR, Vogiatzi N, Remis JP, Savage DF. Identification of a carbonic anhydrase-Rubisco complex within the alpha- carboxysome. Proc Natl Acad Sci U S A 2023; 120:e2308600120. [PMID: 37862384 PMCID: PMC10614612 DOI: 10.1073/pnas.2308600120] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2023] [Accepted: 08/28/2023] [Indexed: 10/22/2023] Open
Abstract
Carboxysomes are proteinaceous organelles that encapsulate key enzymes of CO2 fixation-Rubisco and carbonic anhydrase-and are the centerpiece of the bacterial CO2 concentrating mechanism (CCM). In the CCM, actively accumulated cytosolic bicarbonate diffuses into the carboxysome and is converted to CO2 by carbonic anhydrase, producing a high CO2 concentration near Rubisco and ensuring efficient carboxylation. Self-assembly of the α-carboxysome is orchestrated by the intrinsically disordered scaffolding protein, CsoS2, which interacts with both Rubisco and carboxysomal shell proteins, but it is unknown how the carbonic anhydrase, CsoSCA, is incorporated into the α-carboxysome. Here, we present the structural basis of carbonic anhydrase encapsulation into α-carboxysomes from Halothiobacillus neapolitanus. We find that CsoSCA interacts directly with Rubisco via an intrinsically disordered N-terminal domain. A 1.98 Å single-particle cryoelectron microscopy structure of Rubisco in complex with this peptide reveals that CsoSCA binding is predominantly mediated by a network of hydrogen bonds. CsoSCA's binding site overlaps with that of CsoS2, but the two proteins utilize substantially different motifs and modes of binding, revealing a plasticity of the Rubisco binding site. Our results advance the understanding of carboxysome biogenesis and highlight the importance of Rubisco, not only as an enzyme but also as a central hub for mediating assembly through protein interactions.
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Affiliation(s)
- Cecilia Blikstad
- Department of Molecular and Cell Biology, University of California, Berkeley, CA94720
- Department of Chemistry - Ångström Laboratory, Uppsala University, Uppsala75120, Sweden
| | - Eli J. Dugan
- Department of Molecular and Cell Biology, University of California, Berkeley, CA94720
| | - Thomas G. Laughlin
- Department of Molecular and Cell Biology, University of California, Berkeley, CA94720
| | - Julia B. Turnšek
- Department of Molecular and Cell Biology, University of California, Berkeley, CA94720
| | - Mira D. Liu
- Department of Chemistry, University of California, Berkeley, CA94720
| | - Sophie R. Shoemaker
- Department of Molecular and Cell Biology, University of California, Berkeley, CA94720
| | - Nikoleta Vogiatzi
- Department of Chemistry - Ångström Laboratory, Uppsala University, Uppsala75120, Sweden
| | - Jonathan P. Remis
- California Institute for Quantitative Biosciences, University of California, Berkeley, CA94720
| | - David F. Savage
- Department of Molecular and Cell Biology, University of California, Berkeley, CA94720
- HHMI, University of California, Berkeley, CA94720
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7
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Chen X, Zheng F, Wang P, Mi H. Novel protein CcmS is required for stabilization of the assembly of β-carboxysome in Synechocystis sp. strain PCC 6803. New Phytol 2023. [PMID: 37271831 DOI: 10.1111/nph.19016] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Subscribe] [Scholar Register] [Received: 03/23/2023] [Accepted: 05/08/2023] [Indexed: 06/06/2023]
Abstract
The carboxysome plays an essential role in the carbon concentration mechanism in cyanobacteria. Although significant progress has been made in the structural analysis of the carboxysome, little is still known about its biosynthesis. We identified slr1911, a gene encoding a protein of unknown function in cyanobacterium Synechocystis sp. Strain PCC 6803 (Syn6803), which we termed ccmS by screening a low CO2 -sensitive mutant. CcmS interacts with CcmK1 and CcmM. The former is a shell protein of the β-carboxysome and the latter is a crucial component of the β-carboxysome, which is responsible for aggregating RuBisCO and recruiting shell proteins. The deletion of ccmS lowers the accumulation and assembly of CcmK1, resulting in aberrant carboxysomes, suppressed photosynthetic capacities, and leads to a slow growth phenotype, especially under CO2 -limited conditions. These observations suggest that CcmS stabilizes the assembly of the β-carboxysome shell and likely connects the carboxysome core with the shell. Our results provide a molecular view of the role played by CcmS in the formation of the β-carboxysome and its function in Syn6803.
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Affiliation(s)
- Xin Chen
- National Key Laboratory of Plant Molecular Genetics, CAS Center for Excellence in Molecular Plant Sciences, Institute of Plant Physiology and Ecology, Chinese Academy of Science, 300 Fenglin Road, Shanghai, 200032, China
| | - Fangfang Zheng
- National Key Laboratory of Plant Molecular Genetics, CAS Center for Excellence in Molecular Plant Sciences, Institute of Plant Physiology and Ecology, Chinese Academy of Science, 300 Fenglin Road, Shanghai, 200032, China
| | - Peng Wang
- National Key Laboratory of Plant Molecular Genetics, CAS Center for Excellence in Molecular Plant Sciences, Institute of Plant Physiology and Ecology, Chinese Academy of Science, 300 Fenglin Road, Shanghai, 200032, China
| | - Hualing Mi
- National Key Laboratory of Plant Molecular Genetics, CAS Center for Excellence in Molecular Plant Sciences, Institute of Plant Physiology and Ecology, Chinese Academy of Science, 300 Fenglin Road, Shanghai, 200032, China
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8
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Evans SL, Al-Hazeem MMJ, Mann D, Smetacek N, Beavil AJ, Sun Y, Chen T, Dykes GF, Liu LN, Bergeron JRC. Single-particle cryo-EM analysis of the shell architecture and internal organization of an intact α- carboxysome. Structure 2023; 31:677-688.e4. [PMID: 37015227 PMCID: PMC10689251 DOI: 10.1016/j.str.2023.03.008] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2022] [Revised: 01/19/2023] [Accepted: 03/09/2023] [Indexed: 04/05/2023]
Abstract
Carboxysomes are proteinaceous bacterial microcompartments that sequester the key enzymes for carbon fixation in cyanobacteria and some proteobacteria. They consist of a virus-like icosahedral shell, encapsulating several enzymes, including ribulose 1,5-bisphosphate carboxylase/oxygenase (RuBisCO), responsible for the first step of the Calvin-Benson-Bassham cycle. Despite their significance in carbon fixation and great bioengineering potentials, the structural understanding of native carboxysomes is currently limited to low-resolution studies. Here, we report the characterization of a native α-carboxysome from a marine cyanobacterium by single-particle cryoelectron microscopy (cryo-EM). We have determined the structure of its RuBisCO enzyme, and obtained low-resolution maps of its icosahedral shell, and of its concentric interior organization. Using integrative modeling approaches, we have proposed a complete atomic model of an intact carboxysome, providing insight into its organization and assembly. This is critical for a better understanding of the carbon fixation mechanism and toward repurposing carboxysomes in synthetic biology for biotechnological applications.
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Affiliation(s)
- Sasha L Evans
- Randall Centre for Cell and Molecular Biophysics, King's College London, London, UK
| | - Monsour M J Al-Hazeem
- Institute of Systems, Molecular and Integrative Biology, University of Liverpool, Liverpool, UK
| | - Daniel Mann
- Ernst-Ruska Centre 3, Forschungszentrum Jülich, Jülich, Germany
| | - Nicolas Smetacek
- Department of Molecular Biology and Biotechnology, The University of Sheffield, Sheffield, UK
| | - Andrew J Beavil
- Randall Centre for Cell and Molecular Biophysics, King's College London, London, UK
| | - Yaqi Sun
- Institute of Systems, Molecular and Integrative Biology, University of Liverpool, Liverpool, UK
| | - Taiyu Chen
- Institute of Systems, Molecular and Integrative Biology, University of Liverpool, Liverpool, UK
| | - Gregory F Dykes
- Institute of Systems, Molecular and Integrative Biology, University of Liverpool, Liverpool, UK
| | - Lu-Ning Liu
- Institute of Systems, Molecular and Integrative Biology, University of Liverpool, Liverpool, UK; College of Marine Life Sciences, and Frontiers Science Center for Deep Ocean Multispheres and Earth System, Ocean University of China, Qingdao, Shandong, China.
| | - Julien R C Bergeron
- Randall Centre for Cell and Molecular Biophysics, King's College London, London, UK; Department of Molecular Biology and Biotechnology, The University of Sheffield, Sheffield, UK.
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9
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Kupriyanova EV, Pronina NA, Los DA. Adapting from Low to High: An Update to CO 2-Concentrating Mechanisms of Cyanobacteria and Microalgae. Plants (Basel) 2023; 12:1569. [PMID: 37050194 PMCID: PMC10096703 DOI: 10.3390/plants12071569] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 02/22/2023] [Revised: 04/03/2023] [Accepted: 04/04/2023] [Indexed: 06/19/2023]
Abstract
The intracellular accumulation of inorganic carbon (Ci) by microalgae and cyanobacteria under ambient atmospheric CO2 levels was first documented in the 80s of the 20th Century. Hence, a third variety of the CO2-concentrating mechanism (CCM), acting in aquatic photoautotrophs with the C3 photosynthetic pathway, was revealed in addition to the then-known schemes of CCM, functioning in CAM and C4 higher plants. Despite the low affinity of ribulose-1,5-bisphosphate carboxylase/oxygenase (Rubisco) of microalgae and cyanobacteria for the CO2 substrate and low CO2/O2 specificity, CCM allows them to perform efficient CO2 fixation in the reductive pentose phosphate (RPP) cycle. CCM is based on the coordinated operation of strategically located carbonic anhydrases and CO2/HCO3- uptake systems. This cooperation enables the intracellular accumulation of HCO3-, which is then employed to generate a high concentration of CO2 molecules in the vicinity of Rubisco's active centers compensating up for the shortcomings of enzyme features. CCM functions as an add-on to the RPP cycle while also acting as an important regulatory link in the interaction of dark and light reactions of photosynthesis. This review summarizes recent advances in the study of CCM molecular and cellular organization in microalgae and cyanobacteria, as well as the fundamental principles of its functioning and regulation.
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10
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Ang WSL, How JA, How JB, Mueller-Cajar O. The stickers and spacers of Rubiscondensation: assembling the centrepiece of biophysical CO2-concentrating mechanisms. J Exp Bot 2023; 74:612-626. [PMID: 35903998 DOI: 10.1093/jxb/erac321] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/12/2022] [Accepted: 07/21/2022] [Indexed: 06/15/2023]
Abstract
Aquatic autotrophs that fix carbon using ribulose 1,5-bisphosphate carboxylase/oxygenase (Rubisco) frequently expend metabolic energy to pump inorganic carbon towards the enzyme's active site. A central requirement of this strategy is the formation of highly concentrated Rubisco condensates (or Rubiscondensates) known as carboxysomes and pyrenoids, which have convergently evolved multiple times in prokaryotes and eukaryotes, respectively. Recent data indicate that these condensates form by the mechanism of liquid-liquid phase separation. This mechanism requires networks of weak multivalent interactions typically mediated by intrinsically disordered scaffold proteins. Here we comparatively review recent rapid developments that detail the determinants and precise interactions that underlie diverse Rubisco condensates. The burgeoning field of biomolecular condensates has few examples where liquid-liquid phase separation can be linked to clear phenotypic outcomes. When present, Rubisco condensates are essential for photosynthesis and growth, and they are thus emerging as powerful and tractable models to investigate the structure-function relationship of phase separation in biology.
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Affiliation(s)
- Warren Shou Leong Ang
- School of Biological Sciences, Nanyang Technological University, 60 Nanyang Drive, 637551, Singapore
| | - Jian Ann How
- School of Biological Sciences, Nanyang Technological University, 60 Nanyang Drive, 637551, Singapore
| | - Jian Boon How
- School of Biological Sciences, Nanyang Technological University, 60 Nanyang Drive, 637551, Singapore
| | - Oliver Mueller-Cajar
- School of Biological Sciences, Nanyang Technological University, 60 Nanyang Drive, 637551, Singapore
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11
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Minagawa J, Dann M. Extracellular CahB1 from Sodalinema gerasimenkoae IPPAS B-353 Acts as a Functional Carboxysomal β-Carbonic Anhydrase in Synechocystis sp. PCC6803. Plants (Basel) 2023; 12:265. [PMID: 36678979 PMCID: PMC9865033 DOI: 10.3390/plants12020265] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/23/2022] [Revised: 12/27/2022] [Accepted: 01/03/2023] [Indexed: 06/17/2023]
Abstract
Cyanobacteria mostly rely on the active uptake of hydrated CO2 (i.e., bicarbonate ions) from the surrounding media to fuel their inorganic carbon assimilation. The dehydration of bicarbonate in close vicinity of RuBisCO is achieved through the activity of carboxysomal carbonic anhydrase (CA) enzymes. Simultaneously, many cyanobacterial genomes encode extracellular α- and β-class CAs (EcaA, EcaB) whose exact physiological role remains largely unknown. To date, the CahB1 enzyme of Sodalinema gerasimenkoae (formerly Microcoleus/Coleofasciculus chthonoplastes) remains the sole described active extracellular β-CA in cyanobacteria, but its molecular features strongly suggest it to be a carboxysomal rather than a secreted protein. Upon expression of CahB1 in Synechocystis sp. PCC6803, we found that its expression complemented the loss of endogenous CcaA. Moreover, CahB1 was found to localize to a carboxysome-harboring and CA-active cell fraction. Our data suggest that CahB1 retains all crucial properties of a cellular carboxysomal CA and that the secretion mechanism and/or the machinations of the Sodalinema gerasimenkoae carboxysome are different from those of Synechocystis.
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Affiliation(s)
- Jun Minagawa
- Division of Environmental Photobiology, National Institute for Basic Biology (NIBB), Aichi, Okazaki 444-8585, Japan
| | - Marcel Dann
- Division of Environmental Photobiology, National Institute for Basic Biology (NIBB), Aichi, Okazaki 444-8585, Japan
- Plant Molecular Biology, Ludwig-Maximilian University (LMU) Munich, 82152 Planegg, Germany
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12
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Sutter M, Kerfeld CA, Scott KM. Atypical Carboxysome Loci: JEEPs or Junk? Front Microbiol 2022; 13:872708. [PMID: 35668770 PMCID: PMC9164163 DOI: 10.3389/fmicb.2022.872708] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2022] [Accepted: 03/10/2022] [Indexed: 11/13/2022] Open
Abstract
Carboxysomes, responsible for a substantial fraction of CO2 fixation on Earth, are proteinaceous microcompartments found in many autotrophic members of domain Bacteria, primarily from the phyla Proteobacteria and Cyanobacteria. Carboxysomes facilitate CO2 fixation by the Calvin-Benson-Bassham (CBB) cycle, particularly under conditions where the CO2 concentration is variable or low, or O2 is abundant. These microcompartments are composed of an icosahedral shell containing the enzymes ribulose 1,5-carboxylase/oxygenase (RubisCO) and carbonic anhydrase. They function as part of a CO2 concentrating mechanism, in which cells accumulate HCO3 - in the cytoplasm via active transport, HCO3 - enters the carboxysomes through pores in the carboxysomal shell proteins, and carboxysomal carbonic anhydrase facilitates the conversion of HCO3 - to CO2, which RubisCO fixes. Two forms of carboxysomes have been described: α-carboxysomes and β-carboxysomes, which arose independently from ancestral microcompartments. The α-carboxysomes present in Proteobacteria and some Cyanobacteria have shells comprised of four types of proteins [CsoS1 hexamers, CsoS4 pentamers, CsoS2 assembly proteins, and α-carboxysomal carbonic anhydrase (CsoSCA)], and contain form IA RubisCO (CbbL and CbbS). In the majority of cases, these components are encoded in the genome near each other in a gene locus, and transcribed together as an operon. Interestingly, genome sequencing has revealed some α-carboxysome loci that are missing genes encoding one or more of these components. Some loci lack the genes encoding RubisCO, others lack a gene encoding carbonic anhydrase, some loci are missing shell protein genes, and in some organisms, genes homologous to those encoding the carboxysome-associated carbonic anhydrase are the only carboxysome-related genes present in the genome. Given that RubisCO, assembly factors, carbonic anhydrase, and shell proteins are all essential for carboxysome function, these absences are quite intriguing. In this review, we provide an overview of the most recent studies of the structural components of carboxysomes, describe the genomic context and taxonomic distribution of atypical carboxysome loci, and propose functions for these variants. We suggest that these atypical loci are JEEPs, which have modified functions based on the presence of Just Enough Essential Parts.
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Affiliation(s)
| | | | - Markus Sutter
- MSU-DOE Plant Research Laboratory, Michigan State University, East Lansing, MI, United States
- Environmental Genomics and Systems Biology and Molecular Biophysics and Integrated Bioimaging Divisions, Lawrence Berkeley National Laboratory, Berkeley, CA, United States
| | - Cheryl A. Kerfeld
- MSU-DOE Plant Research Laboratory, Michigan State University, East Lansing, MI, United States
- Environmental Genomics and Systems Biology and Molecular Biophysics and Integrated Bioimaging Divisions, Lawrence Berkeley National Laboratory, Berkeley, CA, United States
| | - Kathleen M. Scott
- Integrative Biology Department, University of South Florida, Tampa, FL, United States
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13
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Sun Y, Harman VM, Johnson JR, Brownridge PJ, Chen T, Dykes GF, Lin Y, Beynon RJ, Liu LN. Decoding the Absolute Stoichiometric Composition and Structural Plasticity of α- Carboxysomes. mBio 2022;:e0362921. [PMID: 35343789 DOI: 10.1128/mbio.03629-21] [Citation(s) in RCA: 19] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023] Open
Abstract
Carboxysomes are anabolic bacterial microcompartments that play an essential role in carbon fixation in cyanobacteria and some chemoautotrophs. This self-assembling organelle encapsulates the key CO2-fixing enzymes, Rubisco, and carbonic anhydrase using a polyhedral protein shell that is constructed by hundreds of shell protein paralogs. The α-carboxysome from the chemoautotroph Halothiobacillus neapolitanus serves as a model system in fundamental studies and synthetic engineering of carboxysomes. In this study, we adopted a QconCAT-based quantitative mass spectrometry approach to determine the stoichiometric composition of native α-carboxysomes from H. neapolitanus. We further performed an in-depth comparison of the protein stoichiometry of native α-carboxysomes and their recombinant counterparts heterologously generated in Escherichia coli to evaluate the structural variability and remodeling of α-carboxysomes. Our results provide insight into the molecular principles that mediate carboxysome assembly, which may aid in rational design and reprogramming of carboxysomes in new contexts for biotechnological applications. IMPORTANCE A wide range of bacteria use special protein-based organelles, termed bacterial microcompartments, to encase enzymes and reactions to increase the efficiency of biological processes. As a model bacterial microcompartment, the carboxysome contains a protein shell filled with the primary carbon fixation enzyme Rubisco. The self-assembling organelle is generated by hundreds of proteins and plays important roles in converting carbon dioxide to sugar, a process known as carbon fixation. In this study, we uncovered the exact stoichiometry of all building components and the structural plasticity of the functional α-carboxysome, using newly developed quantitative mass spectrometry together with biochemistry, electron microscopy, and enzymatic assay. The study advances our understanding of the architecture and modularity of natural carboxysomes. The knowledge learned from natural carboxysomes will suggest feasible ways to produce functional carboxysomes in other hosts, such as crop plants, with the overwhelming goal of boosting cell metabolism and crop yields.
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14
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Chen T, Fang Y, Jiang Q, Dykes GF, Lin Y, Price GD, Long BM, Liu LN. Incorporation of Functional Rubisco Activases into Engineered Carboxysomes to Enhance Carbon Fixation. ACS Synth Biol 2022; 11:154-161. [PMID: 34664944 PMCID: PMC8787814 DOI: 10.1021/acssynbio.1c00311] [Citation(s) in RCA: 24] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
![]()
The carboxysome is
a versatile paradigm of prokaryotic organelles
and is a proteinaceous self-assembling microcompartment that plays
essential roles in carbon fixation in all cyanobacteria and some chemoautotrophs.
The carboxysome encapsulates
the central CO2-fixing enzyme, ribulose-1,5-bisphosphate
carboxylase/oxygenase (Rubisco), using a polyhedral protein shell
that is selectively permeable to specific metabolites in favor of
Rubisco carboxylation. There is tremendous interest in repurposing
carboxysomes to boost carbon fixation in heterologous organisms. Here,
we develop the design and engineering of α-carboxysomes by coexpressing
the Rubisco activase components CbbQ and CbbO with α-carboxysomes
in Escherichia coli. Our results show
that CbbQ and CbbO could assemble into the reconstituted α-carboxysome
as intrinsic components. Incorporation of both CbbQ and CbbO within
the carboxysome promotes activation of Rubisco and enhances the CO2-fixation activities of recombinant carboxysomes. We also
show that the structural composition of these carboxysomes could be
modified in different expression systems, representing the plasticity
of the carboxysome architecture. In translational terms, our study
informs strategies for engineering and modulating carboxysomes in
diverse biotechnological applications.
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Affiliation(s)
- Taiyu Chen
- Institute of Systems, Molecular and Integrative Biology, University of Liverpool, Crown Street, Liverpool L69 7ZB, U.K
- National Key Laboratory of Crop Genetic Improvement and National Center of Plant Gene Research, Huazhong Agricultural University, Wuhan 430070, China
| | - Yi Fang
- Institute of Systems, Molecular and Integrative Biology, University of Liverpool, Crown Street, Liverpool L69 7ZB, U.K
| | - Qiuyao Jiang
- Institute of Systems, Molecular and Integrative Biology, University of Liverpool, Crown Street, Liverpool L69 7ZB, U.K
| | - Gregory F. Dykes
- Institute of Systems, Molecular and Integrative Biology, University of Liverpool, Crown Street, Liverpool L69 7ZB, U.K
| | - Yongjun Lin
- National Key Laboratory of Crop Genetic Improvement and National Center of Plant Gene Research, Huazhong Agricultural University, Wuhan 430070, China
| | - G. Dean Price
- Australian Research Council Centre of Excellence for Translational Photosynthesis, Research School of Biology, Australian National University, 134 Linnaeus Way, Acton, Australian Capital Territory 2601, Australia
| | - Benedict M. Long
- Australian Research Council Centre of Excellence for Translational Photosynthesis, Research School of Biology, Australian National University, 134 Linnaeus Way, Acton, Australian Capital Territory 2601, Australia
| | - Lu-Ning Liu
- Institute of Systems, Molecular and Integrative Biology, University of Liverpool, Crown Street, Liverpool L69 7ZB, U.K
- College of Marine Life Sciences, and Frontiers Science Center for Deep Ocean Multispheres and Earth System, Ocean University of China, Qingdao 266003, China
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15
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Abstract
Carboxysomes are a family of bacterial microcompartments (BMCs), present in all cyanobacteria and some proteobacteria, which encapsulate the primary CO2-fixing enzyme, Rubisco, within a virus-like polyhedral protein shell. Carboxysomes provide significantly elevated levels of CO2 around Rubisco to maximize carboxylation and reduce wasteful photorespiration, thus functioning as the central CO2-fixation organelles of bacterial CO2-concentration mechanisms. Their intriguing architectural features allow carboxysomes to make a vast contribution to carbon assimilation on a global scale. In this review, we discuss recent research progress that provides new insights into the mechanisms of how carboxysomes are assembled and functionally maintained in bacteria and recent advances in synthetic biology to repurpose the metabolic module in diverse applications.
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Affiliation(s)
- Lu-Ning Liu
- Institute of Systems, Molecular and Integrative Biology, University of Liverpool, Crown Street, Liverpool L69 7ZB, UK; College of Marine Life Sciences, and Frontiers Science Center for Deep Ocean Multispheres and Earth System, Ocean University of China, 266003 Qingdao, China.
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16
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Iñiguez C, Aguiló-Nicolau P, Galmés J. Improving photosynthesis through the enhancement of Rubisco carboxylation capacity. Biochem Soc Trans 2021; 49:2007-2019. [PMID: 34623388 DOI: 10.1042/bst20201056] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2021] [Revised: 09/07/2021] [Accepted: 09/09/2021] [Indexed: 12/14/2022]
Abstract
Rising human population, along with the reduction in arable land and the impacts of global change, sets out the need for continuously improving agricultural resource use efficiency and crop yield (CY). Bioengineering approaches for photosynthesis optimization have largely demonstrated the potential for enhancing CY. This review is focused on the improvement of Rubisco functioning, which catalyzes the rate-limiting step of CO2 fixation required for plant growth, but also catalyzes the ribulose-bisphosphate oxygenation initiating the carbon and energy wasteful photorespiration pathway. Rubisco carboxylation capacity can be enhanced by engineering the Rubisco large and/or small subunit genes to improve its catalytic traits, or by engineering the mechanisms that provide enhanced Rubisco expression, activation and/or elevated [CO2] around the active sites to favor carboxylation over oxygenation. Recent advances have been made in the expression, assembly and activation of foreign (either natural or mutant) faster and/or more CO2-specific Rubisco versions. Some components of CO2 concentrating mechanisms (CCMs) from bacteria, algae and C4 plants has been successfully expressed in tobacco and rice. Still, none of the transformed plant lines expressing foreign Rubisco versions and/or simplified CCM components were able to grow faster than wild type plants under present atmospheric [CO2] and optimum conditions. However, the results obtained up to date suggest that it might be achievable in the near future. In addition, photosynthetic and yield improvements have already been observed when manipulating Rubisco quantity and activation degree in crops. Therefore, engineering Rubisco carboxylation capacity continues being a promising target for the improvement in photosynthesis and yield.
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Affiliation(s)
- Concepción Iñiguez
- Research Group on Plant Biology Under Mediterranean Conditions, Universitat de les Illes Balears-INAGEA, Palma, Balearic Islands, Spain
- Department of Ecology, Faculty of Sciences, University of Málaga, Málaga, Spain
| | - Pere Aguiló-Nicolau
- Research Group on Plant Biology Under Mediterranean Conditions, Universitat de les Illes Balears-INAGEA, Palma, Balearic Islands, Spain
| | - Jeroni Galmés
- Research Group on Plant Biology Under Mediterranean Conditions, Universitat de les Illes Balears-INAGEA, Palma, Balearic Islands, Spain
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17
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Melnicki MR, Sutter M, Kerfeld CA. Evolutionary relationships among shell proteins of carboxysomes and metabolosomes. Curr Opin Microbiol 2021; 63:1-9. [PMID: 34098411 PMCID: PMC8525121 DOI: 10.1016/j.mib.2021.05.011] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2021] [Revised: 04/16/2021] [Accepted: 05/17/2021] [Indexed: 12/20/2022]
Abstract
Bacterial microcompartments (BMCs) are self-assembling prokaryotic organelles which encapsulate enzymes within a polyhedral protein shell. The shells are comprised of only two structural modules, distinct domains that form pentagonal and hexagonal building blocks, which occupy the vertices and facets, respectively. As all BMC loci encode at least one hexamer-forming and one pentamer-forming protein, the evolutionary history of BMCs can be interrogated from the perspective of their shells. Here, we discuss how structures of intact shells and detailed phylogenies of their building blocks from a recent phylogenomic survey distinguish families of these domains and reveal clade-specific structural features. These features suggest distinct functional roles that recur across diverse BMCs. For example, it is clear that carboxysomes independently arose twice from metabolosomes, yet the principles of shell assembly are remarkably conserved.
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Affiliation(s)
- Matthew R Melnicki
- Michigan State University-U.S. Department of Energy (MSU-DOE) Plant Research Laboratory and Department of Biochemistry and Molecular Biology, Michigan State University, East Lansing, MI 48824, USA
| | - Markus Sutter
- Michigan State University-U.S. Department of Energy (MSU-DOE) Plant Research Laboratory and Department of Biochemistry and Molecular Biology, Michigan State University, East Lansing, MI 48824, USA; Environmental Genomics and Systems Biology Division and Molecular Biophysics and Integrated Bioimaging Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA
| | - Cheryl A Kerfeld
- Michigan State University-U.S. Department of Energy (MSU-DOE) Plant Research Laboratory and Department of Biochemistry and Molecular Biology, Michigan State University, East Lansing, MI 48824, USA; Environmental Genomics and Systems Biology Division and Molecular Biophysics and Integrated Bioimaging Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA.
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18
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Rillema R, Hoang Y, MacCready JS, Vecchiarelli AG. Carboxysome Mispositioning Alters Growth, Morphology, and Rubisco Level of the Cyanobacterium Synechococcus elongatus PCC 7942. mBio 2021; 12:e0269620. [PMID: 34340540 PMCID: PMC8406218 DOI: 10.1128/mbio.02696-20] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2021] [Accepted: 07/01/2021] [Indexed: 12/23/2022] Open
Abstract
Cyanobacteria are the prokaryotic group of phytoplankton responsible for a significant fraction of global CO2 fixation. Like plants, cyanobacteria use the enzyme ribulose 1,5-bisphosphate carboxylase/oxidase (Rubisco) to fix CO2 into organic carbon molecules via the Calvin-Benson-Bassham cycle. Unlike plants, cyanobacteria evolved a carbon-concentrating organelle called the carboxysome-a proteinaceous compartment that encapsulates and concentrates Rubisco along with its CO2 substrate. In the rod-shaped cyanobacterium Synechococcus elongatus PCC 7942, we recently identified the McdAB system responsible for uniformly distributing carboxysomes along the cell length. It remains unknown what role carboxysome positioning plays with respect to cellular physiology. Here, we show that a failure to distribute carboxysomes leads to slower cell growth, cell elongation, asymmetric cell division, and elevated levels of cellular Rubisco. Unexpectedly, we also report that even wild-type S. elongatus undergoes cell elongation and asymmetric cell division when grown at the cool, but environmentally relevant, growth temperature of 20°C or when switched from a high- to ambient-CO2 environment. The findings suggest that carboxysome positioning by the McdAB system functions to maintain the carbon fixation efficiency of Rubisco by preventing carboxysome aggregation, which is particularly important under growth conditions where rod-shaped cyanobacteria adopt a filamentous morphology. IMPORTANCE Photosynthetic cyanobacteria are responsible for almost half of global CO2 fixation. Due to eutrophication, rising temperatures, and increasing atmospheric CO2 concentrations, cyanobacteria have gained notoriety for their ability to form massive blooms in both freshwater and marine ecosystems across the globe. Like plants, cyanobacteria use the most abundant enzyme on Earth, Rubisco, to provide the sole source of organic carbon required for its photosynthetic growth. Unlike plants, cyanobacteria have evolved a carbon-concentrating organelle called the carboxysome that encapsulates and concentrates Rubisco with its CO2 substrate to significantly increase carbon fixation efficiency and cell growth. We recently identified the positioning system that distributes carboxysomes in cyanobacteria. However, the physiological consequence of carboxysome mispositioning in the absence of this distribution system remains unknown. Here, we find that carboxysome mispositioning triggers changes in cell growth and morphology as well as elevated levels of cellular Rubisco.
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Affiliation(s)
- Rees Rillema
- Department of Molecular, Cellular, and Developmental Biology, University of Michigan, Ann Arbor, Michigan, USA
| | - Y Hoang
- Department of Molecular, Cellular, and Developmental Biology, University of Michigan, Ann Arbor, Michigan, USA
| | - Joshua S. MacCready
- Department of Molecular, Cellular, and Developmental Biology, University of Michigan, Ann Arbor, Michigan, USA
| | - Anthony G. Vecchiarelli
- Department of Molecular, Cellular, and Developmental Biology, University of Michigan, Ann Arbor, Michigan, USA
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19
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Bobik TA, Stewart AM. Selective molecular transport across the protein shells of bacterial microcompartments. Curr Opin Microbiol 2021; 62:76-83. [PMID: 34087617 PMCID: PMC8286307 DOI: 10.1016/j.mib.2021.05.006] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2021] [Revised: 04/20/2021] [Accepted: 05/17/2021] [Indexed: 12/14/2022]
Abstract
Bacterial microcompartments are widespread organelles that play important roles in the environment and are associated with a number of human diseases. A key feature of bacterial MCPs is a selectively permeable protein shell that mediates the movement of substrates, products and cofactors in and out. Here we discuss current knowledge of selective transport across the protein shells of bacterial MCPs, including mechanisms, regulation and unanswered questions.
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Affiliation(s)
- Thomas A Bobik
- The Roy J. Carver Department of Biochemistry, Biophysics and Molecular Biology, Iowa State University, Ames, IA 50011, USA.
| | - Andrew M Stewart
- The Roy J. Carver Department of Biochemistry, Biophysics and Molecular Biology, Iowa State University, Ames, IA 50011, USA
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20
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Scott KM, Harmer TL, Gemmell BJ, Kramer AM, Sutter M, Kerfeld CA, Barber KS, Bari S, Boling JW, Campbell CP, Gallard-Gongora JF, Jackson JK, Lobos A, Mounger JM, Radulovic PW, Sanson JM, Schmid S, Takieddine C, Warlick KF, Whittaker R. Ubiquity and functional uniformity in CO2 concentrating mechanisms in multiple phyla of Bacteria is suggested by a diversity and prevalence of genes encoding candidate dissolved inorganic carbon transporters. FEMS Microbiol Lett 2021; 367:5863185. [PMID: 32589217 DOI: 10.1093/femsle/fnaa106] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2020] [Accepted: 06/23/2020] [Indexed: 12/15/2022] Open
Abstract
Autotrophic microorganisms catalyze the entry of dissolved inorganic carbon (DIC; = CO2 + HCO3- + CO32-) into the biological component of the global carbon cycle, despite dramatic differences in DIC abundance and composition in their sometimes extreme environments. "Cyanobacteria" are known to have CO2 concentrating mechanisms (CCMs) to facilitate growth under low CO2 conditions. These CCMs consist of carboxysomes, containing enzymes ribulose 1,5-bisphosphate oxygenase and carbonic anhydrase, partnered to DIC transporters. CCMs and their DIC transporters have been studied in a handful of other prokaryotes, but it was not known how common CCMs were beyond "Cyanobacteria". Since it had previously been noted that genes encoding potential transporters were found neighboring carboxysome loci, α-carboxysome loci were gathered from bacterial genomes, and potential transporter genes neighboring these loci are described here. Members of transporter families whose members all transport DIC (CHC, MDT and Sbt) were common in these neighborhoods, as were members of the SulP transporter family, many of which transport DIC. 109 of 115 taxa with carboxysome loci have some form of DIC transporter encoded in their genomes, suggesting that CCMs consisting of carboxysomes and DIC transporters are widespread not only among "Cyanobacteria", but also among members of "Proteobacteria" and "Actinobacteria".
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Affiliation(s)
- Kathleen M Scott
- Department of Integrative Biology, University of South Florida, Tampa, FL 33620 USA
| | - Tara L Harmer
- Biology Program, Stockton University, Galloway, NJ, USA
| | - Bradford J Gemmell
- Department of Integrative Biology, University of South Florida, Tampa, FL 33620 USA
| | - Andrew M Kramer
- Department of Integrative Biology, University of South Florida, Tampa, FL 33620 USA
| | - Markus Sutter
- Environmental Genomics and Systems Biology and Molecular Biophysics and Integrated Bioimaging Divisions, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA
| | - Cheryl A Kerfeld
- MSU-DOE Plant Research Laboratory, Michigan State University, East Lansing, MI 48824, USA.,Environmental Genomics and Systems Biology and Molecular Biophysics and Integrated Bioimaging Divisions, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA
| | - Kourtney S Barber
- Department of Integrative Biology, University of South Florida, Tampa, FL 33620 USA
| | - Saaurav Bari
- Department of Integrative Biology, University of South Florida, Tampa, FL 33620 USA
| | - Joshua W Boling
- Department of Integrative Biology, University of South Florida, Tampa, FL 33620 USA
| | - Cassandra P Campbell
- Department of Integrative Biology, University of South Florida, Tampa, FL 33620 USA
| | | | - Jessica K Jackson
- Department of Integrative Biology, University of South Florida, Tampa, FL 33620 USA
| | - Aldo Lobos
- Department of Integrative Biology, University of South Florida, Tampa, FL 33620 USA
| | - Jeannie M Mounger
- Department of Integrative Biology, University of South Florida, Tampa, FL 33620 USA
| | - Peter W Radulovic
- Department of Integrative Biology, University of South Florida, Tampa, FL 33620 USA
| | - Jacqueline M Sanson
- Department of Integrative Biology, University of South Florida, Tampa, FL 33620 USA
| | - Sarah Schmid
- Department of Integrative Biology, University of South Florida, Tampa, FL 33620 USA
| | - Candice Takieddine
- Department of Integrative Biology, University of South Florida, Tampa, FL 33620 USA
| | - Kiley F Warlick
- Department of Integrative Biology, University of South Florida, Tampa, FL 33620 USA
| | - Robert Whittaker
- Department of Integrative Biology, University of South Florida, Tampa, FL 33620 USA
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21
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Zhang Y, Zhou J, Zhang Y, Liu T, Lu X, Men D, Zhang XE. Auxiliary Module Promotes the Synthesis of Carboxysomes in E. coli to Achieve High-Efficiency CO 2 Assimilation. ACS Synth Biol 2021; 10:707-715. [PMID: 33723997 DOI: 10.1021/acssynbio.0c00436] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
Carboxysomes (CBs) are protein organelles in cyanobacteria, and they play a central role in assimilation of CO2. Heterologous synthesis of CBs in E. coli provides an opportunity for CO2-organic compound conversion under controlled conditions but remains challenging; specifically, the CO2 assimilation efficiency is insufficient. In this study, an auxiliary module was designed to assist self-assembly of CBs derived from a model species cyanobacteria Prochlorococcus marinus (P. marinus) MED4 for synthesizing in E. coli. The results indicated that the structural integrity of synthetic CBs is improved through the transmission electron microscope images and that the CBs have highly efficient CO2-concentrating ability as revealed by enzyme kinetic analysis. Furthermore, the bacterial growth curve and 13C-metabolic flux analysis not only consolidated the fact of CO2 assimilation by synthetic CBs in E. coli but also proved that the engineered strain could efficiently convert external CO2 to some metabolic intermediates (acetyl-CoA, malate, fumarate, tyrosine, etc.) of the central metabolic pathway. The synthesis of CBs of P. marinus MED4 in E. coli provides prospects for understanding their CO2 assimilation mechanism and realizing their modular application in synthetic biology.
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Affiliation(s)
- Yuwei Zhang
- State Key Laboratory of Virology, Wuhan Institute of Virology, Center for Biosafety Mega-Science, Chinese Academy of Sciences, Wuhan 430071, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Juan Zhou
- State Key Laboratory of Virology, Wuhan Institute of Virology, Center for Biosafety Mega-Science, Chinese Academy of Sciences, Wuhan 430071, China
| | - Yuchen Zhang
- Key Laboratory of Combinatorial Biosynthesis and Drug Discovery, Ministry of Education and School of Pharmaceutical Sciences, Wuhan University, Wuhan 430071, P. R. China
| | - Tiangang Liu
- Key Laboratory of Combinatorial Biosynthesis and Drug Discovery, Ministry of Education and School of Pharmaceutical Sciences, Wuhan University, Wuhan 430071, P. R. China
| | - Xiaoyun Lu
- Key Laboratory of Systems Microbial Biotechnology, Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin 300308, China
| | - Dong Men
- State Key Laboratory of Virology, Wuhan Institute of Virology, Center for Biosafety Mega-Science, Chinese Academy of Sciences, Wuhan 430071, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Xian-En Zhang
- National Laboratory of Biomacromolecules, CAS Center for Excellence in Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, China
- University of Chinese Academy of Sciences, Beijing 100049, China
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22
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Stewart AM, Stewart KL, Yeates TO, Bobik TA. Advances in the World of Bacterial Microcompartments. Trends Biochem Sci 2021; 46:406-416. [PMID: 33446424 DOI: 10.1016/j.tibs.2020.12.002] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2020] [Revised: 11/30/2020] [Accepted: 12/02/2020] [Indexed: 12/20/2022]
Abstract
Bacterial microcompartments (MCPs) are extremely large (100-400 nm) and diverse proteinaceous organelles that compartmentalize multistep metabolic pathways, increasing their efficiency and sequestering toxic and/or volatile intermediates. This review highlights recent studies that have expanded our understanding of the diversity, structure, function, and potential biotechnological uses of MCPs. Several new types of MCPs have been identified and characterized revealing new functions and potential new associations with human disease. Recent structural studies of MCP proteins and recombinant MCP shells have provided new insights into MCP assembly and mechanisms and raised new questions about MCP structure. We also discuss recent work on biotechnology applications that use MCP principles to develop nanobioreactors, nanocontainers, and molecular scaffolds.
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Affiliation(s)
- Andrew M Stewart
- The Roy J. Carver Department of Biochemistry, Biophysics and Molecular Biology, Iowa State University, Ames, IA, USA
| | - Katie L Stewart
- The Roy J. Carver Department of Biochemistry, Biophysics and Molecular Biology, Iowa State University, Ames, IA, USA
| | - Todd O Yeates
- Department of Chemistry and Biochemistry, University of California, Los Angeles, CA, USA; UCLA-DOE Institute for Genomics and Proteomics, Los Angeles, CA, USA.
| | - Thomas A Bobik
- The Roy J. Carver Department of Biochemistry, Biophysics and Molecular Biology, Iowa State University, Ames, IA, USA.
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23
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Abstract
A mechanism for concentrating carbon dioxide has for the first time been successfully transferred into a species that lacks such a process.
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Affiliation(s)
- Eric Franklin
- Department of Molecular Biology, Princeton University, Princeton, United States
| | - Martin Jonikas
- Department of Molecular Biology, Princeton University, Princeton, United States
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24
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Flamholz AI, Dugan E, Blikstad C, Gleizer S, Ben-Nissan R, Amram S, Antonovsky N, Ravishankar S, Noor E, Bar-Even A, Milo R, Savage DF. Functional reconstitution of a bacterial CO 2 concentrating mechanism in Escherichia coli. eLife 2020; 9:59882. [PMID: 33084575 PMCID: PMC7714395 DOI: 10.7554/elife.59882] [Citation(s) in RCA: 55] [Impact Index Per Article: 13.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2020] [Accepted: 10/20/2020] [Indexed: 12/19/2022] Open
Abstract
Many photosynthetic organisms employ a CO2 concentrating mechanism (CCM) to increase the rate of CO2 fixation via the Calvin cycle. CCMs catalyze ≈50% of global photosynthesis, yet it remains unclear which genes and proteins are required to produce this complex adaptation. We describe the construction of a functional CCM in a non-native host, achieved by expressing genes from an autotrophic bacterium in an Escherichia coli strain engineered to depend on rubisco carboxylation for growth. Expression of 20 CCM genes enabled E. coli to grow by fixing CO2 from ambient air into biomass, with growth in ambient air depending on the components of the CCM. Bacterial CCMs are therefore genetically compact and readily transplanted, rationalizing their presence in diverse bacteria. Reconstitution enabled genetic experiments refining our understanding of the CCM, thereby laying the groundwork for deeper study and engineering of the cell biology supporting CO2 assimilation in diverse organisms.
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Affiliation(s)
- Avi I Flamholz
- Department of Molecular and Cell Biology, University of California, BerkeleyBerkeleyUnited States
| | - Eli Dugan
- Department of Molecular and Cell Biology, University of California, BerkeleyBerkeleyUnited States
| | - Cecilia Blikstad
- Department of Molecular and Cell Biology, University of California, BerkeleyBerkeleyUnited States
| | - Shmuel Gleizer
- Department of Plant and Environmental Sciences, Weizmann Institute of ScienceRehovotIsrael
| | - Roee Ben-Nissan
- Department of Plant and Environmental Sciences, Weizmann Institute of ScienceRehovotIsrael
| | - Shira Amram
- Department of Plant and Environmental Sciences, Weizmann Institute of ScienceRehovotIsrael
| | - Niv Antonovsky
- Department of Plant and Environmental Sciences, Weizmann Institute of ScienceRehovotIsrael
| | - Sumedha Ravishankar
- Department of Molecular and Cell Biology, University of California, BerkeleyBerkeleyUnited States
| | - Elad Noor
- Department of Plant and Environmental Sciences, Weizmann Institute of ScienceRehovotIsrael
| | - Arren Bar-Even
- Max Planck Institute of Molecular Plant PhysiologyPotsdamGermany
| | - Ron Milo
- Department of Plant and Environmental Sciences, Weizmann Institute of ScienceRehovotIsrael
| | - David F Savage
- Department of Molecular and Cell Biology, University of California, BerkeleyBerkeleyUnited States
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25
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Kerfeld CA, Sutter M. Engineered bacterial microcompartments: apps for programming metabolism. Curr Opin Biotechnol 2020; 65:225-232. [PMID: 32554213 PMCID: PMC7719235 DOI: 10.1016/j.copbio.2020.05.001] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2020] [Revised: 05/04/2020] [Accepted: 05/06/2020] [Indexed: 12/12/2022]
Abstract
Bacterial Microcompartments (BMCs) are used by diverse bacteria to compartmentalize enzymatic reactions, functioning analogously to the organelles of eukaryotes. The bounding membrane and encapsulated components are composed entirely of protein, which makes them ideal targets for modification by genetic engineering. In contrast to viruses, in which generally only one protein forms the capsid, the shells of BMCs consist of a variety of shell proteins, each a potential unit of selection. Despite their differences in permeability, the shell proteins are surprisingly interchangeable. Recent developments have shown that they are also highly amenable to engineered modifications which poise them for a variety of biotechnological applications. Given their modular structure, with a module defined as a semi-autonomous functional unit, BMCs can be considered apps for programming metabolism that can be de-bugged by adaptive evolution.
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Affiliation(s)
- Cheryl A Kerfeld
- MSU-DOE Plant Research Laboratory and Department of Biochemistry & Molecular Biology, Michigan State University, East Lansing, MI, USA; Environmental Genomics and Systems Biology and Molecular Biophysics and Integrated Bioimaging Divisions, Lawrence Berkeley National Laboratory, 1 Cyclotron Road, Berkeley, CA 94720, USA.
| | - Markus Sutter
- MSU-DOE Plant Research Laboratory and Department of Biochemistry & Molecular Biology, Michigan State University, East Lansing, MI, USA; Environmental Genomics and Systems Biology and Molecular Biophysics and Integrated Bioimaging Divisions, Lawrence Berkeley National Laboratory, 1 Cyclotron Road, Berkeley, CA 94720, USA
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26
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Flecken M, Wang H, Popilka L, Hartl FU, Bracher A, Hayer-Hartl M. Dual Functions of a Rubisco Activase in Metabolic Repair and Recruitment to Carboxysomes. Cell 2020; 183:457-473.e20. [PMID: 32979320 DOI: 10.1016/j.cell.2020.09.010] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2020] [Revised: 07/13/2020] [Accepted: 09/01/2020] [Indexed: 01/19/2023]
Abstract
Rubisco, the key enzyme of CO2 fixation in photosynthesis, is prone to inactivation by inhibitory sugar phosphates. Inhibited Rubisco undergoes conformational repair by the hexameric AAA+ chaperone Rubisco activase (Rca) in a process that is not well understood. Here, we performed a structural and mechanistic analysis of cyanobacterial Rca, a close homolog of plant Rca. In the Rca:Rubisco complex, Rca is positioned over the Rubisco catalytic site under repair and pulls the N-terminal tail of the large Rubisco subunit (RbcL) into the hexamer pore. Simultaneous displacement of the C terminus of the adjacent RbcL opens the catalytic site for inhibitor release. An alternative interaction of Rca with Rubisco is mediated by C-terminal domains that resemble the small Rubisco subunit. These domains, together with the N-terminal AAA+ hexamer, ensure that Rca is packaged with Rubisco into carboxysomes. The cyanobacterial Rca is a dual-purpose protein with functions in Rubisco repair and carboxysome organization.
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Affiliation(s)
- Mirkko Flecken
- Department of Cellular Biochemistry, Max Planck Institute of Biochemistry, Am Klopferspitz 18, 82152 Martinsried, Germany
| | - Huping Wang
- Department of Cellular Biochemistry, Max Planck Institute of Biochemistry, Am Klopferspitz 18, 82152 Martinsried, Germany
| | - Leonhard Popilka
- Department of Cellular Biochemistry, Max Planck Institute of Biochemistry, Am Klopferspitz 18, 82152 Martinsried, Germany
| | - F Ulrich Hartl
- Department of Cellular Biochemistry, Max Planck Institute of Biochemistry, Am Klopferspitz 18, 82152 Martinsried, Germany
| | - Andreas Bracher
- Department of Cellular Biochemistry, Max Planck Institute of Biochemistry, Am Klopferspitz 18, 82152 Martinsried, Germany
| | - Manajit Hayer-Hartl
- Department of Cellular Biochemistry, Max Planck Institute of Biochemistry, Am Klopferspitz 18, 82152 Martinsried, Germany.
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27
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Ochoa JM, Nguyen VN, Nie M, Sawaya MR, Bobik TA, Yeates TO. Symmetry breaking and structural polymorphism in a bacterial microcompartment shell protein for choline utilization. Protein Sci 2020; 29:2201-2212. [PMID: 32885887 DOI: 10.1002/pro.3941] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2020] [Revised: 08/28/2020] [Accepted: 09/01/2020] [Indexed: 01/02/2023]
Abstract
Bacterial microcompartments are protein-based organelles that carry out specialized metabolic functions in diverse bacteria. Their outer shells are built from several thousand protein subunits. Some of the architectural principles of bacterial microcompartments have been articulated, with lateral packing of flat hexameric BMC proteins providing the basic foundation for assembly. Nonetheless, a complete understanding has been elusive, partly owing to polymorphic mechanisms of assembly exhibited by most microcompartment types. An earlier study of one homologous BMC shell protein subfamily, EutS/PduU, revealed a profoundly bent, rather than flat, hexameric structure. The possibility of a specialized architectural role was hypothesized, but artifactual effects of crystallization could not be ruled out. Here we report a series of crystal structures of an orthologous protein, CutR, from a glycyl-radical type choline-utilizing microcompartment from the bacterium Streptococcus intermedius. Depending on crystal form, expression construct, and minor mutations, a range of novel quaternary architectures was observed, including two spiral hexagonal assemblies. A new graphical approach helps illuminate the variations in BMC hexameric structure, with results substantiating the idea that the EutS/PduU/CutR subfamily of BMC proteins may endow microcompartment shells with flexible modes of assembly.
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Affiliation(s)
- Jessica M Ochoa
- UCLA-Molecular Biology Institute, University of California, Los Angeles (UCLA), California, Los Angeles, USA
| | - Vy N Nguyen
- Department of Chemistry and Biochemistry, University of California, Los Angeles (UCLA), California, Los Angeles, USA
| | - Mengxiao Nie
- Department of Chemistry and Biochemistry, University of California, Los Angeles (UCLA), California, Los Angeles, USA
| | - Michael R Sawaya
- UCLA-DOE Institute of Genomics and Proteomics, University of California, Los Angeles (UCLA), California, Los Angeles, USA
| | - Thomas A Bobik
- Department of Biochemistry, Biophysics and Molecular Biology; Iowa State University, Ames, Iowa, USA
| | - Todd O Yeates
- UCLA-Molecular Biology Institute, University of California, Los Angeles (UCLA), California, Los Angeles, USA.,Department of Chemistry and Biochemistry, University of California, Los Angeles (UCLA), California, Los Angeles, USA.,UCLA-DOE Institute of Genomics and Proteomics, University of California, Los Angeles (UCLA), California, Los Angeles, USA
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28
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Sun Y, Huang F, Dykes GF, Liu LN. Diurnal Regulation of In Vivo Localization and CO 2-Fixing Activity of Carboxysomes in Synechococcus elongatus PCC 7942. Life (Basel) 2020; 10:E169. [PMID: 32872408 PMCID: PMC7555275 DOI: 10.3390/life10090169] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2020] [Revised: 08/23/2020] [Accepted: 08/27/2020] [Indexed: 12/13/2022] Open
Abstract
Carboxysomes are the specific CO2-fixing microcompartments in all cyanobacteria. Although it is known that the organization and subcellular localization of carboxysomes are dependent on external light conditions and are highly relevant to their functions, how carboxysome organization and function are actively orchestrated in natural diurnal cycles has remained elusive. Here, we explore the dynamic regulation of carboxysome positioning and carbon fixation in the model cyanobacterium Synechococcus elongatus PCC 7942 in response to diurnal light-dark cycles, using live-cell confocal imaging and Rubisco assays. We found that carboxysomes are prone to locate close to the central line along the short axis of the cell and exhibit a greater preference of polar distribution in the dark phase, coupled with a reduction in carbon fixation. Moreover, we show that deleting the gene encoding the circadian clock protein KaiA could lead to an increase in carboxysome numbers per cell and reduced portions of pole-located carboxysomes. Our study provides insight into the diurnal regulation of carbon fixation in cyanobacteria and the general cellular strategies of cyanobacteria living in natural habitat for environmental acclimation.
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Affiliation(s)
| | | | | | - Lu-Ning Liu
- Institute of Systems, Molecular and Integrative Biology, University of Liverpool, Liverpool L69 7ZB, UK; (Y.S.); (F.H.); (G.F.D.)
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29
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Huang F, Kong WW, Sun Y, Chen T, Dykes GF, Jiang YL, Liu LN. Rubisco accumulation factor 1 (Raf1) plays essential roles in mediating Rubisco assembly and carboxysome biogenesis. Proc Natl Acad Sci U S A 2020; 117:17418-28. [PMID: 32636267 DOI: 10.1073/pnas.2007990117] [Citation(s) in RCA: 33] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Carboxysomes are membrane-free organelles for carbon assimilation in cyanobacteria. The carboxysome consists of a proteinaceous shell that structurally resembles virus capsids and internal enzymes including ribulose 1,5-bisphosphate carboxylase/oxygenase (Rubisco), the primary carbon-fixing enzyme in photosynthesis. The formation of carboxysomes requires hierarchical self-assembly of thousands of protein subunits, initiated from Rubisco assembly and packaging to shell encapsulation. Here we study the role of Rubisco assembly factor 1 (Raf1) in Rubisco assembly and carboxysome formation in a model cyanobacterium, Synechococcus elongatus PCC7942 (Syn7942). Cryo-electron microscopy reveals that Raf1 facilitates Rubisco assembly by mediating RbcL dimer formation and dimer-dimer interactions. Syn7942 cells lacking Raf1 are unable to form canonical intact carboxysomes but generate a large number of intermediate assemblies comprising Rubisco, CcaA, CcmM, and CcmN without shell encapsulation and a low abundance of carboxysome-like structures with reduced dimensions and irregular shell shapes and internal organization. As a consequence, the Raf1-depleted cells exhibit reduced Rubisco content, CO2-fixing activity, and cell growth. Our results provide mechanistic insight into the chaperone-assisted Rubisco assembly and biogenesis of carboxysomes. Advanced understanding of the biogenesis and stepwise formation process of the biogeochemically important organelle may inform strategies for heterologous engineering of functional CO2-fixing modules to improve photosynthesis.
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30
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Rohnke BA, Rodríguez Pérez KJ, Montgomery BL. Linking the Dynamic Response of the Carbon Dioxide-Concentrating Mechanism to Carbon Assimilation Behavior in Fremyella diplosiphon. mBio 2020; 11:e01052-20. [PMID: 32457252 PMCID: PMC7251215 DOI: 10.1128/mbio.01052-20] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2020] [Accepted: 04/29/2020] [Indexed: 12/31/2022] Open
Abstract
Cyanobacteria use a carbon dioxide (CO2)-concentrating mechanism (CCM) that enhances their carbon fixation efficiency and is regulated by many environmental factors that impact photosynthesis, including carbon availability, light levels, and nutrient access. Efforts to connect the regulation of the CCM by these factors to functional effects on carbon assimilation rates have been complicated by the aqueous nature of cyanobacteria. Here, we describe the use of cyanobacteria in a semiwet state on glass fiber filtration discs-cyanobacterial discs-to establish dynamic carbon assimilation behavior using gas exchange analysis. In combination with quantitative PCR (qPCR) and transmission electron microscopy (TEM) analyses, we linked the regulation of CCM components to corresponding carbon assimilation behavior in the freshwater, filamentous cyanobacterium Fremyella diplosiphon Inorganic carbon (Ci) levels, light quantity, and light quality have all been shown to influence carbon assimilation behavior in F. diplosiphon Our results suggest a biphasic model of cyanobacterial carbon fixation. While behavior at low levels of CO2 is driven mainly by the Ci uptake ability of the cyanobacterium, at higher CO2 levels, carbon assimilation behavior is multifaceted and depends on Ci availability, carboxysome morphology, linear electron flow, and cell shape. Carbon response curves (CRCs) generated via gas exchange analysis enable rapid examination of CO2 assimilation behavior in cyanobacteria and can be used for cells grown under distinct conditions to provide insight into how CO2 assimilation correlates with the regulation of critical cellular functions, such as the environmental control of the CCM and downstream photosynthetic capacity.IMPORTANCE Environmental regulation of photosynthesis in cyanobacteria enhances organismal fitness, light capture, and associated carbon fixation under dynamic conditions. Concentration of carbon dioxide (CO2) near the carbon-fixing enzyme RubisCO occurs via the CO2-concentrating mechanism (CCM). The CCM is also tuned in response to carbon availability, light quality or levels, or nutrient access-cues that also impact photosynthesis. We adapted dynamic gas exchange methods generally used with plants to investigate environmental regulation of the CCM and carbon fixation capacity using glass fiber-filtered cells of the cyanobacterium Fremyella diplosiphon We describe a breakthrough in measuring real-time carbon uptake and associated assimilation capacity for cells grown in distinct conditions (i.e., light quality, light quantity, or carbon status). These measurements demonstrate that the CCM modulates carbon uptake and assimilation under low-Ci conditions and that light-dependent regulation of pigmentation, cell shape, and downstream stages of carbon fixation are critical for tuning carbon uptake and assimilation.
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Affiliation(s)
- Brandon A Rohnke
- DOE-Plant Research Laboratory, Michigan State University, East Lansing, Michigan, USA
- Department of Biochemistry and Molecular Biology, Michigan State University, East Lansing, Michigan, USA
| | - Kiara J Rodríguez Pérez
- DOE-Plant Research Laboratory, Michigan State University, East Lansing, Michigan, USA
- University of Puerto Rico at Arecibo, Arecibo, Puerto Rico
| | - Beronda L Montgomery
- DOE-Plant Research Laboratory, Michigan State University, East Lansing, Michigan, USA
- Department of Biochemistry and Molecular Biology, Michigan State University, East Lansing, Michigan, USA
- Department of Microbiology and Molecular Genetics, Michigan State University, East Lansing, Michigan, USA
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31
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Abstract
Although cyanobacteria and algae represent a small fraction of the biomass of all primary producers, their photosynthetic activity accounts for roughly half of the daily CO2 fixation that occurs on Earth. These microorganisms are able to accomplish this feat by enhancing the activity of the CO2-fixing enzyme Rubisco using biophysical CO2 concentrating mechanisms (CCMs). Biophysical CCMs operate by concentrating bicarbonate and converting it into CO2 in a compartment that houses Rubisco (in contrast with other CCMs that concentrate CO2 via an organic intermediate, such as malate in the case of C4 CCMs). This activity provides Rubisco with a high concentration of its substrate, thereby increasing its reaction rate. The genetic engineering of a biophysical CCM into land plants is being pursued as a strategy to increase crop yields. This review focuses on the progress toward understanding the molecular components of cyanobacterial and algal CCMs, as well as recent advances toward engineering these components into land plants.
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Affiliation(s)
- Jessica H Hennacy
- Department of Molecular Biology, Princeton University, Princeton, New Jersey 08544, USA; ,
| | - Martin C Jonikas
- Department of Molecular Biology, Princeton University, Princeton, New Jersey 08544, USA; ,
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32
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Lundin AP, Stewart KL, Stewart AM, Herring TI, Chowdhury C, Bobik TA. Genetic Characterization of a Glycyl Radical Microcompartment Used for 1,2-Propanediol Fermentation by Uropathogenic Escherichia coli CFT073. J Bacteriol 2020; 202:e00017-20. [PMID: 32071097 DOI: 10.1128/JB.00017-20] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2020] [Accepted: 02/13/2020] [Indexed: 12/29/2022] Open
Abstract
Bacterial microcompartments (MCPs) are widespread protein-based organelles composed of metabolic enzymes encapsulated within a protein shell. The function of MCPs is to optimize metabolic pathways by confining toxic and/or volatile pathway intermediates. A major class of MCPs known as glycyl radical MCPs has only been partially characterized. Here, we show that uropathogenic Escherichia coli CFT073 uses a glycyl radical MCP for 1,2-propanediol (1,2-PD) fermentation. Bioinformatic analyses identified a large gene cluster (named grp for glycyl radical propanediol) that encodes homologs of a glycyl radical diol dehydratase, other 1,2-PD catabolic enzymes, and MCP shell proteins. Growth studies showed that E. coli CFT073 grows on 1,2-PD under anaerobic conditions but not under aerobic conditions. All 19 grp genes were individually deleted, and 8/19 were required for 1,2-PD fermentation. Electron microscopy and genetic studies showed that a bacterial MCP is involved. Bioinformatics combined with genetic analyses support a proposed pathway of 1,2-PD degradation and suggest that enzymatic cofactors are recycled internally within the Grp MCP. A two-component system (grpP and grpQ) is shown to mediate induction of the grp locus by 1,2-PD. Tests of the E. coli Reference (ECOR) collection indicate that >10% of E. coli strains ferment 1,2-PD using a glycyl radical MCP. In contrast to other MCP systems, individual deletions of MCP shell genes (grpE, grpH, and grpI) eliminated 1,2-PD catabolism, suggesting significant functional differences with known MCPs. Overall, the studies presented here are the first comprehensive genetic analysis of a Grp-type MCP.IMPORTANCE Bacterial MCPs have a number of potential biotechnology applications and have been linked to bacterial pathogenesis, cancer, and heart disease. Glycyl radical MCPs are a large but understudied class of bacterial MCPs. Here, we show that uropathogenic E. coli CFT073 uses a glycyl radical MCP for 1,2-PD fermentation, and we conduct a comprehensive genetic analysis of the genes involved. Studies suggest significant functional differences between the glycyl radical MCP of E. coli CFT073 and better-studied MCPs. They also provide a foundation for building a deeper general understanding of glycyl radical MCPs in an organism where sophisticated genetic methods are available.
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33
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Zhu XG, Ort DR, Parry MAJ, von Caemmerer S. A wish list for synthetic biology in photosynthesis research. J Exp Bot 2020; 71:2219-2225. [PMID: 32060550 PMCID: PMC7134917 DOI: 10.1093/jxb/eraa075] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/22/2019] [Accepted: 02/12/2020] [Indexed: 05/02/2023]
Abstract
This perspective summarizes the presentations and discussions at the ' International Symposium on Synthetic Biology in Photosynthesis Research', which was held in Shanghai in 2018. Leveraging the current advanced understanding of photosynthetic systems, the symposium brain-stormed about the redesign and engineering of photosynthetic systems for translational goals and evaluated available new technologies/tools for synthetic biology as well as technological obstacles and new tools that would be needed to overcome them. Four major research areas for redesigning photosynthesis were identified: (i) mining natural variations of photosynthesis; (ii) coordinating photosynthesis with pathways utilizing photosynthate; (iii) reconstruction of highly efficient photosynthetic systems in non-host species; and (iv) development of new photosynthetic systems that do not exist in nature. To expedite photosynthesis synthetic biology research, an array of new technologies and community resources need to be developed, which include expanded modelling capacities, molecular engineering toolboxes, model species, and phenotyping tools.
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Affiliation(s)
- Xin-Guang Zhu
- Institute of Plant Physiology and Ecology and Center for Excellence for Molecular Plant Sciences, Chinese Academy of Sciences, Shanghai, China
| | - Donald R Ort
- Departments of Plant Biology and Crop Sciences, University of Illinois at Urbana Champaign, Urbana, IL, USA
| | - Martin A J Parry
- Lancaster Environment Centre, Lancaster University, Lancaster, UK
| | - Susanne von Caemmerer
- Research School of Biological Sciences, Australian National University, Acton, Australia
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34
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Chowdhury C, Bobik TA. Engineering the PduT shell protein to modify the permeability of the 1,2-propanediol microcompartment of Salmonella. Microbiology (Reading) 2020; 165:1355-1364. [PMID: 31674899 DOI: 10.1099/mic.0.000872] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
Bacterial microcompartments (MCPs) are protein-based organelles that consist of metabolic enzymes encapsulated within a protein shell. The function of MCPs is to optimize metabolic pathways by increasing reaction rates and sequestering toxic pathway intermediates. A substantial amount of effort has been directed toward engineering synthetic MCPs as intracellular nanoreactors for the improved production of renewable chemicals. A key challenge in this area is engineering protein shells that allow the entry of desired substrates. In this study, we used site-directed mutagenesis of the PduT shell protein to remove its central iron-sulfur cluster and create openings (pores) in the shell of the Pdu MCP that have varied chemical properties. Subsequently, in vivo and in vitro studies were used to show that PduT-C38S and PduT-C38A variants increased the diffusion of 1,2-propanediol, propionaldehyde, NAD+ and NADH across the shell of the MCP. In contrast, PduT-C38I and PduT-C38W eliminated the iron-sulfur cluster without altering the permeability of the Pdu MCP, suggesting that the side-chains of C38I and C38W occluded the opening formed by removal of the iron-sulfur cluster. Thus, genetic modification offers an approach to engineering the movement of larger molecules (such as NAD/H) across MCP shells, as well as a method for blocking transport through trimeric bacterial microcompartment (BMC) domain shell proteins.
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Affiliation(s)
- Chiranjit Chowdhury
- Present address: Amity Institute of Molecular Medicine and Stem Cell Research, Amity University Campus, Sector-125, Noida, UP-201313, India.,Roy J. Carver Department of Biochemistry, Biophysics and Molecular Biology, Iowa State University, Ames, IA, 50011, USA
| | - Thomas A Bobik
- Roy J. Carver Department of Biochemistry, Biophysics and Molecular Biology, Iowa State University, Ames, IA, 50011, USA
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35
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Lechno-Yossef S, Rohnke BA, Belza ACO, Melnicki MR, Montgomery BL, Kerfeld CA. Cyanobacterial carboxysomes contain an unique rubisco-activase-like protein. New Phytol 2020; 225:793-806. [PMID: 31518434 DOI: 10.1111/nph.16195] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/25/2019] [Accepted: 09/05/2019] [Indexed: 06/10/2023]
Abstract
In plants, rubisco activase (Rca) regulates rubisco by removing inhibitory molecules such as ribulose-1,5-bisphosphate (RuBP). In cyanobacteria, a homologous protein (activase-like cyanobacterial protein, ALC), contains a distinctive C-terminal fusion resembling the small-subunit of rubisco. Although cyanobacterial rubisco is believed to be less sensitive to RuBP inhibition, the ALC is widely distributed among diverse cyanobacteria. Using microscopy, biochemistry and molecular biology, the cellular localization of the ALC, its effect on carboxysome/cell ultrastructure in Fremyella diplosiphon, and its function in vitro were studied. Bioinformatic analysis uncovered evolutionary relationships between the ALC and rubisco. ALC localizes to carboxysomes and exhibits ATPase activity. Furthermore, the ALC induces rubisco aggregation in a manner similar to that of another carboxysomal protein, M35, and this activity is affected by ATP. An alc deletion mutant showed modified cell morphology when grown under enriched CO2 and impaired regulation of carboxysome biogenesis, without affecting growth rate. Carbamylation of Fremyella recombinant rubisco was inhibited by RuBP, but this inhibition was not relieved by the ALC. The ALC does not appear to function like a canonical Rca; instead, it exerts an effect on the response to CO2 availability at the level of a metabolic module, the carboxysome, through rubisco network formation, and carboxysome organization.
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Affiliation(s)
- Sigal Lechno-Yossef
- MSU-DOE Plant Research Laboratory, Michigan State University, East Lansing, MI, 48824, USA
- Department of Biochemistry and Molecular Biology, Michigan State University, East Lansing, MI, 48824, USA
| | - Brandon A Rohnke
- MSU-DOE Plant Research Laboratory, Michigan State University, East Lansing, MI, 48824, USA
- Department of Biochemistry and Molecular Biology, Michigan State University, East Lansing, MI, 48824, USA
| | - Ana C O Belza
- MSU-DOE Plant Research Laboratory, Michigan State University, East Lansing, MI, 48824, USA
| | - Matthew R Melnicki
- MSU-DOE Plant Research Laboratory, Michigan State University, East Lansing, MI, 48824, USA
| | - Beronda L Montgomery
- MSU-DOE Plant Research Laboratory, Michigan State University, East Lansing, MI, 48824, USA
- Department of Biochemistry and Molecular Biology, Michigan State University, East Lansing, MI, 48824, USA
- Department of Microbiology and Molecular Genetics, Michigan State University, East Lansing, MI, 48824, USA
| | - Cheryl A Kerfeld
- MSU-DOE Plant Research Laboratory, Michigan State University, East Lansing, MI, 48824, USA
- Department of Biochemistry and Molecular Biology, Michigan State University, East Lansing, MI, 48824, USA
- Environmental Genomics and Systems Biology and Molecular Biophysics and Integrated Bioimaging Divisions, Lawrence Berkeley National Laboratory, Berkeley, CA, 94720, USA
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36
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Page MT, Parry MA, Carmo‐Silva E. A high-throughput transient expression system for rice. Plant Cell Environ 2019; 42:2057-2064. [PMID: 30938460 PMCID: PMC6618034 DOI: 10.1111/pce.13542] [Citation(s) in RCA: 28] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/11/2018] [Revised: 02/11/2019] [Accepted: 02/24/2019] [Indexed: 05/18/2023]
Abstract
Rice is an important global crop and represents a vital source of calories for many food insecure regions. Efforts to improve this crop by improving yield, nutritional content, stress tolerance, or resilience to climate change are certain to include biotechnological approaches, which rely on the expression of transgenes in planta. The throughput and cost of currently available transgenic expression systems is frequently incompatible with modern, high-throughput molecular cloning methods. Here, we present a protocol for isolating high yields of green rice protoplasts and for PEG-mediated transformation of isolated protoplasts. Factors affecting transformation efficiency were investigated, and the resulting protocol is fast, cheap, robust, high-throughput, and does not require specialist equipment. When coupled to a high-throughput modular cloning system such as Golden Gate, this transient expression system provides a valuable resource to help break the "design-build-test" bottleneck by permitting the rapid screening of large numbers of transgenic expression cassettes prior to stable plant transformation. We used this system to rapidly assess the expression level, subcellular localisation, and protein aggregation pattern of nine single-gene expression cassettes, which represent the essential component parts of the β-cyanobacterial carboxysome.
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Affiliation(s)
- Mike T. Page
- Lancaster Environment CentreLancaster UniversityLancasterUK
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Ryan P, Forrester TJB, Wroblewski C, Kenney TMG, Kitova EN, Klassen JS, Kimber MS. The small RbcS-like domains of the β- carboxysome structural protein CcmM bind RubisCO at a site distinct from that binding the RbcS subunit. J Biol Chem 2018; 294:2593-2603. [PMID: 30591587 DOI: 10.1074/jbc.ra118.006330] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2018] [Revised: 12/13/2018] [Indexed: 12/26/2022] Open
Abstract
Carboxysomes are compartments in bacterial cells that promote efficient carbon fixation by sequestering RubisCO and carbonic anhydrase within a protein shell that impedes CO2 escape. The key to assembling this protein complex is CcmM, a multidomain protein whose C-terminal region is required for RubisCO recruitment. This CcmM region is built as a series of copies (generally 3-5) of a small domain, CcmMS, joined by unstructured linkers. CcmMS domains have weak, but significant, sequence identity to RubisCO's small subunit, RbcS, suggesting that CcmM binds RubisCO by displacing RbcS. We report here the 1.35-Å structure of the first Thermosynechococcus elongatus CcmMS domain, revealing that it adopts a compact, well-defined structure that resembles that of RbcS. CcmMS, however, lacked key RbcS RubisCO-binding determinants, most notably an extended N-terminal loop. Nevertheless, individual CcmMS domains are able to bind RubisCO in vitro with 1.16 μm affinity. Two or four linked CcmMS domains did not exhibit dramatic increases in this affinity, implying that short, disordered linkers may frustrate successive CcmMS domains attempting to simultaneously bind a single RubisCO oligomer. Size-exclusion chromatography-coupled right-angled light scattering (SEC-RALS) and native MS experiments indicated that multiple CcmMS domains can bind a single RubisCO holoenzyme and, moreover, that RbcS is not released from these complexes. CcmMS bound equally tightly to a RubisCO variant in which the α/β domain of RbcS was deleted, suggesting that CcmMS binds RubisCO independently of its RbcS subunit. We propose that, instead, the electropositive CcmMS may bind to an extended electronegative pocket between RbcL dimers.
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Affiliation(s)
- Patrick Ryan
- From the Department of Molecular and Cellular Biology, University of Guelph, Guelph, Ontario N1G 2W1, Canada and
| | - Taylor J B Forrester
- From the Department of Molecular and Cellular Biology, University of Guelph, Guelph, Ontario N1G 2W1, Canada and
| | - Charles Wroblewski
- From the Department of Molecular and Cellular Biology, University of Guelph, Guelph, Ontario N1G 2W1, Canada and
| | - Tristan M G Kenney
- From the Department of Molecular and Cellular Biology, University of Guelph, Guelph, Ontario N1G 2W1, Canada and
| | - Elena N Kitova
- Alberta Glycomics Centre and Department of Chemistry, University of Alberta, Edmonton, Alberta T6G 2G2, Canada
| | - John S Klassen
- Alberta Glycomics Centre and Department of Chemistry, University of Alberta, Edmonton, Alberta T6G 2G2, Canada
| | - Matthew S Kimber
- From the Department of Molecular and Cellular Biology, University of Guelph, Guelph, Ontario N1G 2W1, Canada and
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Blondeau M, Sachse M, Boulogne C, Gillet C, Guigner JM, Skouri-Panet F, Poinsot M, Ferard C, Miot J, Benzerara K. Amorphous Calcium Carbonate Granules Form Within an Intracellular Compartment in Calcifying Cyanobacteria. Front Microbiol 2018; 9:1768. [PMID: 30127775 PMCID: PMC6087745 DOI: 10.3389/fmicb.2018.01768] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2018] [Accepted: 07/16/2018] [Indexed: 12/17/2022] Open
Abstract
The recent discovery of cyanobacteria forming intracellular amorphous calcium carbonate (ACC) has challenged the former paradigm suggesting that cyanobacteria-mediated carbonatogenesis was exclusively extracellular. Yet, the mechanisms of intracellular biomineralization in cyanobacteria and in particular whether this takes place within an intracellular microcompartment, remain poorly understood. Here, we analyzed six cyanobacterial strains forming intracellular ACC by transmission electron microscopy. We tested two different approaches to preserve as well as possible the intracellular ACC inclusions: (i) freeze-substitution followed by epoxy embedding and room-temperature ultramicrotomy and (ii) high-pressure freezing followed by cryo-ultramicrotomy, usually referred to as cryo-electron microscopy of vitreous sections (CEMOVIS). We observed that the first method preserved ACC well in 500-nm-thick sections but not in 70-nm-thick sections. However, cell ultrastructures were difficult to clearly observe in the 500-nm-thick sections. In contrast, CEMOVIS provided a high preservation quality of bacterial ultrastructures, including the intracellular ACC inclusions in 50-nm-thick sections. ACC inclusions displayed different textures, suggesting varying brittleness, possibly resulting from different hydration levels. Moreover, an electron dense envelope of ∼2.5 nm was systematically observed around ACC granules in all studied cyanobacterial strains. This envelope may be composed of a protein shell or a lipid monolayer, but not a lipid bilayer as usually observed in other bacteria forming intracellular minerals. Overall, this study evidenced that ACC inclusions formed and were stabilized within a previously unidentified bacterial microcompartment in some species of cyanobacteria.
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Affiliation(s)
- Marine Blondeau
- UMR CNRS 7590, IRD, Muséum National d'Histoire Naturelle, Institut de Minéralogie, de Physique des Matériaux et de Cosmochimie, Sorbonne Université, Paris, France
| | - Martin Sachse
- Unité Technologie et Service BioImagerie Ultrastructurale, Citech, Institut Pasteur, Paris, France
| | - Claire Boulogne
- CEA, Centre National de la Recherche Scientifique, Institute for Integrative Biology of the Cell (I2BC), Université Paris-Sud, Université Paris-Saclay, Gif-sur-Yvette, France
| | - Cynthia Gillet
- CEA, Centre National de la Recherche Scientifique, Institute for Integrative Biology of the Cell (I2BC), Université Paris-Sud, Université Paris-Saclay, Gif-sur-Yvette, France
| | - Jean-Michel Guigner
- UMR CNRS 7590, IRD, Muséum National d'Histoire Naturelle, Institut de Minéralogie, de Physique des Matériaux et de Cosmochimie, Sorbonne Université, Paris, France
| | - Fériel Skouri-Panet
- UMR CNRS 7590, IRD, Muséum National d'Histoire Naturelle, Institut de Minéralogie, de Physique des Matériaux et de Cosmochimie, Sorbonne Université, Paris, France
| | - Mélanie Poinsot
- UMR CNRS 7590, IRD, Muséum National d'Histoire Naturelle, Institut de Minéralogie, de Physique des Matériaux et de Cosmochimie, Sorbonne Université, Paris, France
| | - Céline Ferard
- UMR CNRS 7590, IRD, Muséum National d'Histoire Naturelle, Institut de Minéralogie, de Physique des Matériaux et de Cosmochimie, Sorbonne Université, Paris, France
| | - Jennyfer Miot
- UMR CNRS 7590, IRD, Muséum National d'Histoire Naturelle, Institut de Minéralogie, de Physique des Matériaux et de Cosmochimie, Sorbonne Université, Paris, France
| | - Karim Benzerara
- UMR CNRS 7590, IRD, Muséum National d'Histoire Naturelle, Institut de Minéralogie, de Physique des Matériaux et de Cosmochimie, Sorbonne Université, Paris, France
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Abstract
Cyanobacteria sequester photosynthetic enzymes into microcompartments which facilitate the conversion of carbon dioxide into sugars. Geometric similarities between these structures and self-assembling viral capsids have inspired models that posit microcompartments as stable equilibrium arrangements of the constituent proteins. Here we describe a different mechanism for microcompartment assembly, one that is fundamentally nonequilibrium and yet highly reliable. This pathway is revealed by simulations of a molecular model resolving the size and shape of a cargo droplet and the extent and topography of an elastic shell. The resulting metastable microcompartment structures closely resemble those of carboxysomes, with a narrow size distribution and faceted shells. The essence of their assembly dynamics can be understood from a simpler mathematical model that combines elements of classical nucleation theory with continuum elasticity. These results highlight important control variables for achieving nanoscale encapsulation in general and for modulating the size and shape of carboxysomes in particular.
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Herring TI, Harris TN, Chowdhury C, Mohanty SK, Bobik TA. A Bacterial Microcompartment Is Used for Choline Fermentation by Escherichia coli 536. J Bacteriol 2018; 200:e00764-17. [PMID: 29507086 DOI: 10.1128/JB.00764-17] [Citation(s) in RCA: 34] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2017] [Accepted: 02/23/2018] [Indexed: 01/16/2023] Open
Abstract
Bacterial choline degradation in the human gut has been associated with cancer and heart disease. In addition, recent studies found that a bacterial microcompartment is involved in choline utilization by Proteus and Desulfovibrio species. However, many aspects of this process have not been fully defined. Here, we investigate choline degradation by the uropathogen Escherichia coli 536. Growth studies indicated E. coli 536 degrades choline primarily by fermentation. Electron microscopy indicated that a bacterial microcompartment was used for this process. Bioinformatic analyses suggested that the choline utilization (cut) gene cluster of E. coli 536 includes two operons, one containing three genes and a main operon of 13 genes. Regulatory studies indicate that the cutX gene encodes a positive transcriptional regulator required for induction of the main cut operon in response to choline supplementation. Each of the 16 genes in the cut cluster was individually deleted, and phenotypes were examined. The cutX, cutY, cutF, cutO, cutC, cutD, cutU, and cutV genes were required for choline degradation, but the remaining genes of the cut cluster were not essential under the conditions used. The reasons for these varied phenotypes are discussed.IMPORTANCE Here, we investigate choline degradation in E. coli 536. These studies provide a basis for understanding a new type of bacterial microcompartment and may provide deeper insight into the link between choline degradation in the human gut and cancer and heart disease. These are also the first studies of choline degradation in E. coli 536, an organism for which sophisticated genetic analysis methods are available. In addition, the cut gene cluster of E. coli 536 is located in pathogenicity island II (PAI-II536) and hence might contribute to pathogenesis.
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Abstract
Dissociating the complexity of metabolic processes into modules is a shift in focus from the single gene/gene product to functional and evolutionary units spanning the scale of biological organization. When viewing the levels of biological organization through this conceptual lens, modules are found across the continuum: domains within proteins, co-regulated groups of functionally associated genes, operons, metabolic pathways and (sub)cellular compartments. Combining modules as components or subsystems of a larger system typically leads to increased complexity and the emergence of new functions. By virtue of their potential for 'plug and play' into new contexts, modules can be viewed as units of both evolution and engineering. Through consideration of lessons learned from recent efforts to install new metabolic modules into cells and the emerging understanding of the structure, function and assembly of protein-based organelles, bacterial microcompartments, a structural bioengineering approach is described: one that builds from an architectural vocabulary of protein domains. This bioarchitectonic approach to engineering cellular metabolism can be applied to microbial cell factories, used in the programming of members of synthetic microbial communities or used to attain additional levels of metabolic organization in eukaryotic cells for increasing primary productivity and as the foundation of a green economy.This article is part of the themed issue 'Enhancing photosynthesis in crop plants: targets for improvement'.
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Affiliation(s)
- Cheryl A Kerfeld
- MSU-DOE Plant Research Laboratory, Michigan State University, 612 Wilson Road, East Lansing, MI 48824, USA .,Molecular Biophysics and Integrated Bioimaging Division, Lawrence Berkeley National Laboratory, 1 Cyclotron Road, Berkeley, CA 94720, USA.,Department of Biochemistry and Molecular Biology, Michigan State University, 603 Wilson Road, East Lansing, MI 48824, USA.,Department of Plant and Microbial Biology, University of California, 111 Koshland Hall, Berkeley, CA 94720, USA
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Clark RL, Gordon GC, Bennett NR, Lyu H, Root TW, Pfleger BF. High-CO 2 Requirement as a Mechanism for the Containment of Genetically Modified Cyanobacteria. ACS Synth Biol 2018; 7:384-391. [PMID: 29320853 DOI: 10.1021/acssynbio.7b00377] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
As researchers engineer cyanobacteria for biotechnological applications, we must consider potential environmental release of these organisms. Previous theoretical work has considered cyanobacterial containment through elimination of the CO2-concentrating mechanism (CCM) to impose a high-CO2 requirement (HCR), which could be provided in the cultivation environment but not in the surroundings. In this work, we experimentally implemented an HCR containment mechanism in Synechococcus sp. strain PCC7002 (PCC7002) through deletion of carboxysome shell proteins and showed that this mechanism contained cyanobacteria in a 5% CO2 environment. We considered escape through horizontal gene transfer (HGT) and reduced the risk of HGT escape by deleting competence genes. We showed that the HCR containment mechanism did not negatively impact the performance of a strain of PCC7002 engineered for L-lactate production. We showed through coculture experiments of HCR strains with ccm-containing strains that this HCR mechanism reduced the frequency of escape below the NIH recommended limit for recombinant organisms of one escape event in 108 CFU.
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Affiliation(s)
- Ryan L. Clark
- Department
of Chemical and Biological Engineering, University of Wisconsin − Madison, 1415 Engineering Drive, Madison, Wisconsin 53706, United States
| | - Gina C. Gordon
- Department
of Chemical and Biological Engineering, University of Wisconsin − Madison, 1415 Engineering Drive, Madison, Wisconsin 53706, United States
- Microbiology
Doctoral Training Program, University of Wisconsin − Madison, 1550 Linden Drive, Madison, Wisconsin 53706, United States
| | - Nathaniel R. Bennett
- Department
of Chemical and Biological Engineering, University of Wisconsin − Madison, 1415 Engineering Drive, Madison, Wisconsin 53706, United States
| | - Haoxiang Lyu
- Department
of Chemical and Biological Engineering, University of Wisconsin − Madison, 1415 Engineering Drive, Madison, Wisconsin 53706, United States
| | - Thatcher W. Root
- Department
of Chemical and Biological Engineering, University of Wisconsin − Madison, 1415 Engineering Drive, Madison, Wisconsin 53706, United States
| | - Brian F. Pfleger
- Department
of Chemical and Biological Engineering, University of Wisconsin − Madison, 1415 Engineering Drive, Madison, Wisconsin 53706, United States
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Fang Y, Huang F, Faulkner M, Jiang Q, Dykes GF, Yang M, Liu LN. Engineering and Modulating Functional Cyanobacterial CO 2-Fixing Organelles. Front Plant Sci 2018; 9:739. [PMID: 29922315 PMCID: PMC5996877 DOI: 10.3389/fpls.2018.00739] [Citation(s) in RCA: 38] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/29/2018] [Accepted: 05/15/2018] [Indexed: 05/12/2023]
Abstract
Bacterial microcompartments (BMCs) are proteinaceous organelles widespread among bacterial phyla and provide a means for compartmentalizing specific metabolic pathways. They sequester catalytic enzymes from the cytoplasm, using an icosahedral proteinaceous shell with selective permeability to metabolic molecules and substrates, to enhance metabolic efficiency. Carboxysomes were the first BMCs discovered and their unprecedented capacity of CO2 fixation allows cyanobacteria to make a significant contribution to global carbon fixation. There is an increasing interest in utilizing synthetic biology to construct synthetic carboxysomes in new hosts, i.e., higher plants, to enhance carbon fixation and productivity. Here, we report the construction of a synthetic operon of the β-carboxysome from the cyanobacterium Synechococcus elongatus PCC7942 to generate functional β-carboxysome-like structures in Escherichia coli. The protein expression, structure, assembly, and activity of synthetic β-carboxysomes were characterized in depth using confocal, electron and atomic force microscopy, proteomics, immunoblot analysis, and enzymatic assays. Furthermore, we examined the in vivo interchangeability of β-carboxysome building blocks with other BMC components. To our knowledge, this is the first production of functional β-carboxysome-like structures in heterologous organisms. It provides important information for the engineering of fully functional carboxysomes and CO2-fixing modules in higher plants. The study strengthens our synthetic biology toolbox for generating BMC-based organelles with tunable activities and new scaffolding biomaterials for metabolic improvement and molecule delivery.
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Rohnke BA, Singh SP, Pattanaik B, Montgomery BL. RcaE-Dependent Regulation of Carboxysome Structural Proteins Has a Central Role in Environmental Determination of Carboxysome Morphology and Abundance in Fremyella diplosiphon. mSphere 2018; 3:e00617-17. [PMID: 29404416 PMCID: PMC5784247 DOI: 10.1128/msphere.00617-17] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2018] [Accepted: 01/08/2018] [Indexed: 11/20/2022] Open
Abstract
Carboxysomes are central to the carbon dioxide-concentrating mechanism (CCM) and carbon fixation in cyanobacteria. Although the structure is well understood, roles of environmental cues in the synthesis, positioning, and functional tuning of carboxysomes have not been systematically studied. Fremyella diplosiphon is a model cyanobacterium for assessing impacts of environmental light cues on photosynthetic pigmentation and tuning of photosynthetic efficiency during complementary chromatic acclimation (CCA), which is controlled by the photoreceptor RcaE. Given the central role of carboxysomes in photosynthesis, we investigated roles of light-dependent RcaE signaling in carboxysome structure and function. A ΔrcaE mutant exhibits altered carboxysome size and number, ccm gene expression, and carboxysome protein accumulation relative to the wild-type (WT) strain. Several Ccm proteins, including carboxysome shell proteins and core-nucleating factors, overaccumulate in ΔrcaE cells relative to WT cells. Additionally, levels of carboxysome cargo RuBisCO in the ΔrcaE mutant are lower than or unchanged from those in the WT strain. This shift in the ratios of carboxysome shell and nucleating components to the carboxysome cargo appears to drive carboxysome morphology and abundance dynamics. Carboxysomes are also occasionally mislocalized spatially to the periphery of spherical mutants within thylakoid membranes, suggesting that carboxysome positioning is impacted by cell shape. The RcaE photoreceptor links perception of external light cues to regulating carboxysome structure and function and, thus, to the cellular capacity for carbon fixation. IMPORTANCE Carboxysomes are proteinaceous subcellular compartments, or bacterial organelles, found in cyanobacteria that consist of a protein shell surrounding a core primarily composed of the enzyme ribulose-1,5-biphosphate carboxylase/oxygenase (RuBisCO) that is central to the carbon dioxide-concentrating mechanism (CCM) and carbon fixation. Whereas significant insights have been gained regarding the structure and synthesis of carboxysomes, limited attention has been given to how their size, abundance, and protein composition are regulated to ensure optimal carbon fixation in dynamic environments. Given the centrality of carboxysomes in photosynthesis, we provide an analysis of the role of a photoreceptor, RcaE, which functions in matching photosynthetic pigmentation to the external environment during complementary chromatic acclimation and thereby optimizing photosynthetic efficiency, in regulating carboxysome dynamics. Our data highlight a role for RcaE in perceiving external light cues and regulating carboxysome structure and function and, thus, in the cellular capacity for carbon fixation and organismal fitness.
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Affiliation(s)
- Brandon A. Rohnke
- Department of Energy—Plant Research Laboratory, Michigan State University, Plant Biology Laboratories, East Lansing, Michigan, USA
- Department of Biochemistry and Molecular Biology, Michigan State University, East Lansing, Michigan, USA
| | - Shailendra P. Singh
- Department of Energy—Plant Research Laboratory, Michigan State University, Plant Biology Laboratories, East Lansing, Michigan, USA
| | - Bagmi Pattanaik
- Department of Energy—Plant Research Laboratory, Michigan State University, Plant Biology Laboratories, East Lansing, Michigan, USA
| | - Beronda L. Montgomery
- Department of Energy—Plant Research Laboratory, Michigan State University, Plant Biology Laboratories, East Lansing, Michigan, USA
- Department of Biochemistry and Molecular Biology, Michigan State University, East Lansing, Michigan, USA
- Department of Microbiology & Molecular Genetics, Michigan State University, East Lansing, Michigan, USA
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45
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Larsson AM, Hasse D, Valegård K, Andersson I. Crystal structures of β- carboxysome shell protein CcmP: ligand binding correlates with the closed or open central pore. J Exp Bot 2017; 68:3857-3867. [PMID: 28369612 PMCID: PMC5853799 DOI: 10.1093/jxb/erx070] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/14/2016] [Accepted: 02/15/2017] [Indexed: 05/21/2023]
Abstract
Cyanobacterial CO2 fixation is promoted by encapsulating and co-localizing the CO2-fixing enzymes within a protein shell, the carboxysome. A key feature of the carboxysome is its ability to control selectively the flux of metabolites in and out of the shell. The β-carboxysome shell protein CcmP has been shown to form a double layer of pseudohexamers with a relatively large central pore (~13 Å diameter), which may allow passage of larger metabolites such as the substrate for CO2 fixation, ribulose 1,5-bisphosphate, through the shell. Here we describe two crystal structures, at 1.45 Å and 1.65 Å resolution, of CcmP from Synechococcus elongatus PCC7942 (SeCcmP). The central pore of CcmP is open or closed at its ends, depending on the conformation of two conserved residues, Glu69 and Arg70. The presence of glycerol resulted in a pore that is open at one end and closed at the opposite end. When glycerol was omitted, both ends of the barrel became closed. A binding pocket at the interior of the barrel featured residual density with distinct differences in size and shape depending on the conformation, open or closed, of the central pore of SeCcmP, suggestive of a metabolite-driven mechanism for the gating of the pore.
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Affiliation(s)
- Anna M Larsson
- Laboratory of Molecular Biophysics, Department of Cell and Molecular Biology, Uppsala University, Husargatan, Uppsala, Sweden
- Correspondence:
| | - Dirk Hasse
- Laboratory of Molecular Biophysics, Department of Cell and Molecular Biology, Uppsala University, Husargatan, Uppsala, Sweden
| | - Karin Valegård
- Laboratory of Molecular Biophysics, Department of Cell and Molecular Biology, Uppsala University, Husargatan, Uppsala, Sweden
| | - Inger Andersson
- Laboratory of Molecular Biophysics, Department of Cell and Molecular Biology, Uppsala University, Husargatan, Uppsala, Sweden
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Rae BD, Long BM, Förster B, Nguyen ND, Velanis CN, Atkinson N, Hee WY, Mukherjee B, Price GD, McCormick AJ. Progress and challenges of engineering a biophysical CO2-concentrating mechanism into higher plants. J Exp Bot 2017; 68:3717-3737. [PMID: 28444330 DOI: 10.1093/jxb/erx133] [Citation(s) in RCA: 57] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/19/2023]
Abstract
Growth and productivity in important crop plants is limited by the inefficiencies of the C3 photosynthetic pathway. Introducing CO2-concentrating mechanisms (CCMs) into C3 plants could overcome these limitations and lead to increased yields. Many unicellular microautotrophs, such as cyanobacteria and green algae, possess highly efficient biophysical CCMs that increase CO2 concentrations around the primary carboxylase enzyme, Rubisco, to enhance CO2 assimilation rates. Algal and cyanobacterial CCMs utilize distinct molecular components, but share several functional commonalities. Here we outline the recent progress and current challenges of engineering biophysical CCMs into C3 plants. We review the predicted requirements for a functional biophysical CCM based on current knowledge of cyanobacterial and algal CCMs, the molecular engineering tools and research pipelines required to translate our theoretical knowledge into practice, and the current challenges to achieving these goals.
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Affiliation(s)
- Benjamin D Rae
- Australian Research Council Centre of Excellence for Translational Photosynthesis
- Research School of Biology, The Australian National University, 134 Linnaeus Way, Acton ACT 2601, Australia
| | - Benedict M Long
- Research School of Biology, The Australian National University, 134 Linnaeus Way, Acton ACT 2601, Australia
| | - Britta Förster
- Research School of Biology, The Australian National University, 134 Linnaeus Way, Acton ACT 2601, Australia
| | - Nghiem D Nguyen
- Australian Research Council Centre of Excellence for Translational Photosynthesis
- Research School of Biology, The Australian National University, 134 Linnaeus Way, Acton ACT 2601, Australia
| | - Christos N Velanis
- SynthSys and Institute of Molecular Plant Sciences, School of Biological Sciences, University of Edinburgh, Edinburgh EH9 3BF, UK
| | - Nicky Atkinson
- SynthSys and Institute of Molecular Plant Sciences, School of Biological Sciences, University of Edinburgh, Edinburgh EH9 3BF, UK
| | - Wei Yih Hee
- Research School of Biology, The Australian National University, 134 Linnaeus Way, Acton ACT 2601, Australia
| | - Bratati Mukherjee
- Australian Research Council Centre of Excellence for Translational Photosynthesis
- Research School of Biology, The Australian National University, 134 Linnaeus Way, Acton ACT 2601, Australia
| | - G Dean Price
- Australian Research Council Centre of Excellence for Translational Photosynthesis
- Research School of Biology, The Australian National University, 134 Linnaeus Way, Acton ACT 2601, Australia
| | - Alistair J McCormick
- SynthSys and Institute of Molecular Plant Sciences, School of Biological Sciences, University of Edinburgh, Edinburgh EH9 3BF, UK
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Lehman BP, Chowdhury C, Bobik TA. The N Terminus of the PduB Protein Binds the Protein Shell of the Pdu Microcompartment to Its Enzymatic Core. J Bacteriol 2017; 199:e00785-16. [PMID: 28138097 DOI: 10.1128/JB.00785-16] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2016] [Accepted: 01/20/2017] [Indexed: 12/12/2022] Open
Abstract
Bacterial microcompartments (MCPs) are extremely large proteinaceous organelles that consist of an enzymatic core encapsulated within a complex protein shell. A key question in MCP biology is the nature of the interactions that guide the assembly of thousands of protein subunits into a well-ordered metabolic compartment. In this report, we show that the N-terminal 37 amino acids of the PduB protein have a critical role in binding the shell of the 1,2-propanediol utilization (Pdu) microcompartment to its enzymatic core. Several mutations were constructed that deleted short regions of the N terminus of PduB. Growth tests indicated that three of these deletions were impaired MCP assembly. Attempts to purify MCPs from these mutants, followed by gel electrophoresis and enzyme assays, indicated that the protein complexes isolated consisted of MCP shells depleted of core enzymes. Electron microscopy substantiated these findings by identifying apparently empty MCP shells but not intact MCPs. Analyses of 13 site-directed mutants indicated that the key region of the N terminus of PduB required for MCP assembly is a putative helix spanning residues 6 to 18. Considering the findings presented here together with prior work, we propose a new model for MCP assembly.IMPORTANCE Bacterial microcompartments consist of metabolic enzymes encapsulated within a protein shell and are widely used to optimize metabolic process. Here, we show that the N-terminal 37 amino acids of the PduB shell protein are essential for assembly of the 1,2-propanediol utilization microcompartment. The results indicate that it plays a key role in binding the outer shell to the enzymatic core. We propose that this interaction might be used to define the relative orientation of the shell with respect to the core. This finding is of fundamental importance to our understanding of microcompartment assembly and may have application to engineering microcompartments as nanobioreactors for chemical production.
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Mallette E, Kimber MS. A Complete Structural Inventory of the Mycobacterial Microcompartment Shell Proteins Constrains Models of Global Architecture and Transport. J Biol Chem 2016; 292:1197-1210. [PMID: 27927988 DOI: 10.1074/jbc.m116.754093] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2016] [Revised: 12/05/2016] [Indexed: 11/06/2022] Open
Abstract
Bacterial microcompartments are bacterial analogs of eukaryotic organelles in that they spatially segregate aspects of cellular metabolism, but they do so by building not a lipid membrane but a thin polyhedral protein shell. Although multiple shell protein structures are known for several microcompartment types, additional uncharacterized components complicate systematic investigations of shell architecture. We report here the structures of all four proteins proposed to form the shell of an uncharacterized microcompartment designated the Rhodococcus and Mycobacterium microcompartment (RMM), which, along with crystal interactions and docking studies, suggests possible models for the particle's vertex and edge organization. MSM0272 is a typical hexameric β-sandwich shell protein thought to form the bulk of the facet. MSM0273 is a pentameric β-barrel shell protein that likely plugs the vertex of the particle. MSM0271 is an unusual double-ringed bacterial microcompartment shell protein whose rings are organized in an offset position relative to all known related proteins. MSM0275 is related to MSM0271 but self-organizes as linear strips that may line the facet edge; here, the presence of a novel extendable loop may help ameliorate poor packing geometry of the rigid main particle at the angled edges. In contrast to previously characterized homologs, both of these proteins show closed pores at both ends. This suggests a model where key interactions at the vertex and edges are mediated at the inner layer of the shell by MSM0271 (encircling MSM0273) and MSM0275, and the facet is built from MSM0272 hexamers tiling in the outer layer of the shell.
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Affiliation(s)
- Evan Mallette
- From the Department of Molecular and Cellular Biology, University of Guelph, Guelph, Ontario N1G 2W1, Canada
| | - Matthew S Kimber
- From the Department of Molecular and Cellular Biology, University of Guelph, Guelph, Ontario N1G 2W1, Canada
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Wheatley NM, Eden KD, Ngo J, Rosinski JS, Sawaya MR, Cascio D, Collazo M, Hoveida H, Hubbell WL, Yeates TO. A PII-Like Protein Regulated by Bicarbonate: Structural and Biochemical Studies of the Carboxysome-Associated CPII Protein. J Mol Biol 2016; 428:4013-4030. [PMID: 27464895 PMCID: PMC5048545 DOI: 10.1016/j.jmb.2016.07.015] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2016] [Revised: 07/11/2016] [Accepted: 07/18/2016] [Indexed: 11/18/2022]
Abstract
Autotrophic bacteria rely on various mechanisms to increase intracellular concentrations of inorganic forms of carbon (i.e., bicarbonate and CO2) in order to improve the efficiency with which they can be converted to organic forms. Transmembrane bicarbonate transporters and carboxysomes play key roles in accumulating bicarbonate and CO2, but other regulatory elements of carbon concentration mechanisms in bacteria are less understood. In this study, after analyzing the genomic regions around α-type carboxysome operons, we characterize a protein that is conserved across these operons but has not been previously studied. On the basis of a series of apo- and ligand-bound crystal structures and supporting biochemical data, we show that this protein, which we refer to as the carboxysome-associated PII protein (CPII), represents a new and distinct subfamily within the broad superfamily of previously studied PII regulatory proteins, which are generally involved in regulating nitrogen metabolism in bacteria. CPII undergoes dramatic conformational changes in response to ADP binding, and the affinity for nucleotide binding is strongly enhanced by the presence of bicarbonate. CPII therefore appears to be a unique type of PII protein that senses bicarbonate availability, consistent with its apparent genomic association with the carboxysome and its constituents.
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Affiliation(s)
- Nicole M Wheatley
- UCLA-DOE Institute for Genomics and Proteomics, Los Angeles, CA 90095, USA
| | - Kevin D Eden
- Department of Chemistry and Biochemistry, University of California, Los Angeles, CA 90095, USA
| | - Joanna Ngo
- Department of Chemistry and Biochemistry, University of California, Los Angeles, CA 90095, USA
| | - Justin S Rosinski
- Department of Chemistry and Biochemistry, University of California, Los Angeles, CA 90095, USA
| | - Michael R Sawaya
- UCLA-DOE Institute for Genomics and Proteomics, Los Angeles, CA 90095, USA
| | - Duilio Cascio
- UCLA-DOE Institute for Genomics and Proteomics, Los Angeles, CA 90095, USA
| | - Michael Collazo
- UCLA-DOE Institute for Genomics and Proteomics, Los Angeles, CA 90095, USA
| | - Hamidreza Hoveida
- Department of Chemistry and Biochemistry, University of California, Los Angeles, CA 90095, USA
| | - Wayne L Hubbell
- Department of Chemistry and Biochemistry, University of California, Los Angeles, CA 90095, USA; Jules Stein Eye Institute, University of California, Los Angeles, CA 90095, USA
| | - Todd O Yeates
- UCLA-DOE Institute for Genomics and Proteomics, Los Angeles, CA 90095, USA; Department of Chemistry and Biochemistry, University of California, Los Angeles, CA 90095, USA.
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Hanson MR, Lin MT, Carmo-Silva AE, Parry MA. Towards engineering carboxysomes into C3 plants. Plant J 2016; 87:38-50. [PMID: 26867858 PMCID: PMC4970904 DOI: 10.1111/tpj.13139] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/10/2015] [Revised: 01/29/2016] [Accepted: 02/02/2016] [Indexed: 05/18/2023]
Abstract
Photosynthesis in C3 plants is limited by features of the carbon-fixing enzyme Rubisco, which exhibits a low turnover rate and can react with O2 instead of CO2 , leading to photorespiration. In cyanobacteria, bacterial microcompartments, known as carboxysomes, improve the efficiency of photosynthesis by concentrating CO2 near the enzyme Rubisco. Cyanobacterial Rubisco enzymes are faster than those of C3 plants, though they have lower specificity toward CO2 than the land plant enzyme. Replacement of land plant Rubisco by faster bacterial variants with lower CO2 specificity will improve photosynthesis only if a microcompartment capable of concentrating CO2 can also be installed into the chloroplast. We review current information about cyanobacterial microcompartments and carbon-concentrating mechanisms, plant transformation strategies, replacement of Rubisco in a model C3 plant with cyanobacterial Rubisco and progress toward synthesizing a carboxysome in chloroplasts.
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Affiliation(s)
- Maureen R. Hanson
- Department of Molecular Biology and Genetics, Cornell University, Biotechnology Building, Ithaca, NY 14853 USA
| | - Myat T. Lin
- Department of Molecular Biology and Genetics, Cornell University, Biotechnology Building, Ithaca, NY 14853 USA
| | | | - Martin A.J. Parry
- Lancaster Environment Centre, Lancaster University, Lancaster, LA1 4YQ, United Kingdom
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