1
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Turnsek JB, Oltrogge LM, Savage DF. Conserved and repetitive motifs in an intrinsically disordered protein drive ⍺-carboxysome assembly. J Biol Chem 2024:107532. [PMID: 38971311 DOI: 10.1016/j.jbc.2024.107532] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2023] [Revised: 05/30/2024] [Accepted: 06/06/2024] [Indexed: 07/08/2024] Open
Abstract
All cyanobacteria and some chemoautotrophic bacteria fix CO2 into sugars using specialized proteinaceous compartments called carboxysomes. Carboxysomes enclose the enzymes Rubisco and carbonic anhydrase inside a layer of shell proteins to increase the CO2 concentration for efficient carbon fixation by Rubisco. In the ⍺-carboxysome lineage, a disordered and highly repetitive protein named CsoS2 is essential for carboxysome formation and function. Without it, the bacteria require high CO2 to grow. How does a protein predicted to be lacking structure serve as the architectural scaffold for such a vital cellular compartment? In this study, we identify key residues present in the repeats of CsoS2, VTG and Y, which are necessary for building functional ⍺-carboxysomes in vivo. These highly conserved and repetitive residues contribute to the multivalent binding interaction and phase separation behavior between CsoS2 and shell proteins. We also demonstrate 3-component reconstitution of CsoS2, Rubisco, and shell proteins into spherical condensates, and show the utility of reconstitution as a biochemical tool to study carboxysome biogenesis. The precise self-assembly of thousands of proteins is crucial for carboxysome formation, and understanding this process could enable their use in alternative biological hosts or industrial processes as effective tools to fix carbon.
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Affiliation(s)
- Julia B Turnsek
- Department of Molecular and Cell Biology, University of California, Berkeley, California, USA
| | - Luke M Oltrogge
- Department of Molecular and Cell Biology, University of California, Berkeley, California, USA; Howard Hughes Medical Institute, University of California, Berkeley, California, USA
| | - David F Savage
- Department of Molecular and Cell Biology, University of California, Berkeley, California, USA; Howard Hughes Medical Institute, University of California, Berkeley, California, USA; Innovative Genomics Institute, University of California, Berkeley, California, USA.
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2
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Gabr A, Stephens TG, Reinfelder JR, Liau P, Calatrava V, Grossman AR, Bhattacharya D. Evidence of a putative CO 2 delivery system to the chromatophore in the photosynthetic amoeba Paulinella. ENVIRONMENTAL MICROBIOLOGY REPORTS 2024; 16:e13304. [PMID: 38923306 PMCID: PMC11194058 DOI: 10.1111/1758-2229.13304] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/13/2024] [Accepted: 05/22/2024] [Indexed: 06/28/2024]
Abstract
The photosynthetic amoeba, Paulinella provides a recent (ca. 120 Mya) example of primary plastid endosymbiosis. Given the extensive data demonstrating host lineage-driven endosymbiont integration, we analysed nuclear genome and transcriptome data to investigate mechanisms that may have evolved in Paulinella micropora KR01 (hereinafter, KR01) to maintain photosynthetic function in the novel organelle, the chromatophore. The chromatophore is of α-cyanobacterial provenance and has undergone massive gene loss due to Muller's ratchet, but still retains genes that encode the ancestral α-carboxysome and the shell carbonic anhydrase, two critical components of the biophysical CO2 concentrating mechanism (CCM) in cyanobacteria. We identified KR01 nuclear genes potentially involved in the CCM that arose via duplication and divergence and are upregulated in response to high light and downregulated under elevated CO2. We speculate that these genes may comprise a novel CO2 delivery system (i.e., a biochemical CCM) to promote the turnover of the RuBisCO carboxylation reaction and counteract photorespiration. We posit that KR01 has an inefficient photorespiratory system that cannot fully recycle the C2 product of RuBisCO oxygenation back to the Calvin-Benson cycle. Nonetheless, both these systems appear to be sufficient to allow Paulinella to persist in environments dominated by faster-growing phototrophs.
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Affiliation(s)
- Arwa Gabr
- Graduate Program in Molecular Bioscience and Program in Microbiology and Molecular GeneticsRutgers UniversityNew BrunswickNew JerseyUSA
| | - Timothy G. Stephens
- Department of Biochemistry and MicrobiologyRutgers UniversityNew BrunswickNew JerseyUSA
| | - John R. Reinfelder
- Department of Environmental SciencesRutgers UniversityNew BrunswickNew JerseyUSA
| | - Pinky Liau
- Department of Biochemistry and MicrobiologyRutgers UniversityNew BrunswickNew JerseyUSA
| | - Victoria Calatrava
- Department of Plant BiologyThe Carnegie Institution for ScienceStanfordCaliforniaUSA
| | - Arthur R. Grossman
- Department of Plant BiologyThe Carnegie Institution for ScienceStanfordCaliforniaUSA
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3
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Zhou RQ, Jiang YL, Li H, Hou P, Kong WW, Deng JX, Chen Y, Zhou CZ, Zeng Q. Structure and assembly of the α-carboxysome in the marine cyanobacterium Prochlorococcus. NATURE PLANTS 2024; 10:661-672. [PMID: 38589484 DOI: 10.1038/s41477-024-01660-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/08/2023] [Accepted: 02/29/2024] [Indexed: 04/10/2024]
Abstract
Carboxysomes are bacterial microcompartments that encapsulate the enzymes RuBisCO and carbonic anhydrase in a proteinaceous shell to enhance the efficiency of photosynthetic carbon fixation. The self-assembly principles of the intact carboxysome remain elusive. Here we purified α-carboxysomes from Prochlorococcus and examined their intact structures using single-particle cryo-electron microscopy to solve the basic principles of their shell construction and internal RuBisCO organization. The 4.2 Å icosahedral-like shell structure reveals 24 CsoS1 hexamers on each facet and one CsoS4A pentamer at each vertex. RuBisCOs are organized into three concentric layers within the shell, consisting of 72, 32 and up to 4 RuBisCOs at the outer, middle and inner layers, respectively. We uniquely show how full-length and shorter forms of the scaffolding protein CsoS2 bind to the inner surface of the shell via repetitive motifs in the middle and C-terminal regions. Combined with previous reports, we propose a concomitant 'outside-in' assembly principle of α-carboxysomes: the inner surface of the self-assembled shell is reinforced by the middle and C-terminal motifs of the scaffolding protein, while the free N-terminal motifs cluster to recruit RuBisCO in concentric, three-layered spherical arrangements. These new insights into the coordinated assembly of α-carboxysomes may guide the rational design and repurposing of carboxysome structures for improving plant photosynthetic efficiency.
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Affiliation(s)
- Rui-Qian Zhou
- Department of Ocean Science, The Hong Kong University of Science and Technology, Clear Water Bay, Hong Kong, China
- School of Life Sciences, Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei, China
| | - Yong-Liang Jiang
- School of Life Sciences, Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei, China.
| | - Haofu Li
- Department of Ocean Science, The Hong Kong University of Science and Technology, Clear Water Bay, Hong Kong, China
| | - Pu Hou
- School of Life Sciences, Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei, China
| | - Wen-Wen Kong
- School of Life Sciences, Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei, China
| | - Jia-Xin Deng
- School of Life Sciences, Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei, China
| | - Yuxing Chen
- School of Life Sciences, Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei, China
| | - Cong-Zhao Zhou
- School of Life Sciences, Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei, China.
| | - Qinglu Zeng
- Department of Ocean Science, The Hong Kong University of Science and Technology, Clear Water Bay, Hong Kong, 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. FRONTIERS IN PLANT SCIENCE 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] [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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Oltrogge LM, Chen AW, Chaijarasphong T, Turnšek JB, Savage DF. α-Carboxysome Size Is Controlled by the Disordered Scaffold Protein CsoS2. Biochemistry 2024; 63:219-229. [PMID: 38085650 PMCID: PMC10795168 DOI: 10.1021/acs.biochem.3c00403] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2023] [Revised: 11/16/2023] [Accepted: 11/17/2023] [Indexed: 01/17/2024]
Abstract
Carboxysomes are protein microcompartments that function in the bacterial CO2 concentrating mechanism (CCM) to facilitate CO2 assimilation. To do so, carboxysomes assemble from thousands of constituent proteins into an icosahedral shell, which encapsulates the enzymes Rubisco and carbonic anhydrase to form structures typically > 100 nm and > 300 megadaltons. Although many of the protein interactions driving the assembly process have been determined, it remains unknown how size and composition are precisely controlled. Here, we show that the size of α-carboxysomes is controlled by the disordered scaffolding protein CsoS2. CsoS2 contains two classes of related peptide repeats that bind to the shell in a distinct fashion, and our data indicate that size is controlled by the relative number of these interactions. We propose an energetic and structural model wherein the two repeat classes bind at the junction of shell hexamers but differ in their preferences for the shell contact angles, and thus the local curvature. In total, this model suggests that a set of specific and repeated interactions between CsoS2 and shell proteins collectively achieve the large size and monodispersity of α-carboxysomes.
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Affiliation(s)
- Luke M. Oltrogge
- Department
of Molecular and Cell Biology, University
of California, Berkeley, California 94720, United States
- Howard
Hughes Medical Institute, University of California, Berkeley, California 94720, United States
| | - Allen W. Chen
- Department
of Chemistry, University of California, Berkeley, California 94720, United States
| | | | - Julia B. Turnšek
- Department
of Molecular and Cell Biology, University
of California, Berkeley, California 94720, United States
| | - David F. Savage
- Department
of Molecular and Cell Biology, University
of California, Berkeley, California 94720, United States
- Howard
Hughes Medical Institute, University of California, Berkeley, California 94720, United States
- Innovative
Genomics Institute, University of California, Berkeley, California 94720, United States
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6
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Ni T, Jiang Q, Ng PC, Shen J, Dou H, Zhu Y, Radecke J, Dykes GF, Huang F, Liu LN, Zhang P. Intrinsically disordered CsoS2 acts as a general molecular thread for α-carboxysome shell assembly. Nat Commun 2023; 14:5512. [PMID: 37679318 PMCID: PMC10484944 DOI: 10.1038/s41467-023-41211-y] [Citation(s) in RCA: 9] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2023] [Accepted: 08/27/2023] [Indexed: 09/09/2023] Open
Abstract
Carboxysomes are a paradigm of self-assembling proteinaceous organelles found in nature, offering compartmentalisation of enzymes and pathways to enhance carbon fixation. In α-carboxysomes, the disordered linker protein CsoS2 plays an essential role in carboxysome assembly and Rubisco encapsulation. Its mechanism of action, however, is not fully understood. Here we synthetically engineer α-carboxysome shells using minimal shell components and determine cryoEM structures of these to decipher the principle of shell assembly and encapsulation. The structures reveal that the intrinsically disordered CsoS2 C-terminus is well-structured and acts as a universal "molecular thread" stitching through multiple shell protein interfaces. We further uncover in CsoS2 a highly conserved repetitive key interaction motif, [IV]TG, which is critical to the shell assembly and architecture. Our study provides a general mechanism for the CsoS2-governed carboxysome shell assembly and cargo encapsulation and further advances synthetic engineering of carboxysomes for diverse biotechnological applications.
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Affiliation(s)
- Tao Ni
- Division of Structural Biology, Wellcome Trust Centre for Human Genetics, University of Oxford, Oxford, OX3 7BN, UK.
- School of Biomedical Sciences, LKS Faculty of Medicine, The University of Hong Kong, Pokfulam, Hong Kong SAR, China.
| | - Qiuyao Jiang
- Institute of Systems, Molecular and Integrative Biology, University of Liverpool, Liverpool, L69 7ZB, UK
| | - Pei Cing Ng
- Institute of Systems, Molecular and Integrative Biology, University of Liverpool, Liverpool, L69 7ZB, UK
| | - Juan Shen
- Division of Structural Biology, Wellcome Trust Centre for Human Genetics, University of Oxford, Oxford, OX3 7BN, UK
| | - Hao Dou
- Division of Structural Biology, Wellcome Trust Centre for Human Genetics, University of Oxford, Oxford, OX3 7BN, UK
| | - Yanan Zhu
- Division of Structural Biology, Wellcome Trust Centre for Human Genetics, University of Oxford, Oxford, OX3 7BN, UK
| | - Julika Radecke
- Diamond Light Source, Harwell Science and Innovation Campus, Didcot, OX11 0DE, UK
| | - Gregory F Dykes
- Institute of Systems, Molecular and Integrative Biology, University of Liverpool, Liverpool, L69 7ZB, UK
| | - Fang Huang
- Institute of Systems, Molecular and Integrative Biology, University of Liverpool, Liverpool, L69 7ZB, UK
| | - Lu-Ning Liu
- Institute of Systems, Molecular and Integrative Biology, University of Liverpool, Liverpool, L69 7ZB, UK.
- College of Marine Life Sciences, and Frontiers Science Center for Deep Ocean Multispheres and Earth System, Ocean University of China, Qingdao, 266003, China.
| | - Peijun Zhang
- Division of Structural Biology, Wellcome Trust Centre for Human Genetics, University of Oxford, Oxford, OX3 7BN, UK.
- Diamond Light Source, Harwell Science and Innovation Campus, Didcot, OX11 0DE, UK.
- Chinese Academy of Medical Sciences Oxford Institute, University of Oxford, Oxford, OX3 7BN, UK.
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7
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Kimber MS. α-carboxysomes present a multi-layered structural challenge. Structure 2023; 31:639-641. [PMID: 37267921 DOI: 10.1016/j.str.2023.05.004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2023] [Revised: 05/02/2023] [Accepted: 05/04/2023] [Indexed: 06/04/2023]
Abstract
α-carboxysomes are large, heterogeneous bodies that fix CO2 in cyanobacteria. In this issue of Structure, Evans et al. (2023) report a cryo-electron microscopy study of the α-carboxysome from Cyanobium sp. PCC 7001 along with modeling of its icosahedral shell and the packing of RuBisCO within its interior.
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Affiliation(s)
- Matthew S Kimber
- Department of Molecular and Cellular Biology, University of Guelph, Ontario N1G 2W1, Canada.
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8
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Nguyen ND, Pulsford SB, Hee WY, Rae BD, Rourke LM, Price GD, Long BM. Towards engineering a hybrid carboxysome. PHOTOSYNTHESIS RESEARCH 2023; 156:265-277. [PMID: 36892800 PMCID: PMC10154267 DOI: 10.1007/s11120-023-01009-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/14/2022] [Accepted: 02/17/2023] [Indexed: 05/03/2023]
Abstract
Carboxysomes are bacterial microcompartments, whose structural features enable the encapsulated Rubisco holoenzyme to operate in a high-CO2 environment. Consequently, Rubiscos housed within these compartments possess higher catalytic turnover rates relative to their plant counterparts. This particular enzymatic property has made the carboxysome, along with associated transporters, an attractive prospect to incorporate into plant chloroplasts to increase future crop yields. To date, two carboxysome types have been characterized, the α-type that has fewer shell components and the β-type that houses a faster Rubisco. While research is underway to construct a native carboxysome in planta, work investigating the internal arrangement of carboxysomes has identified conserved Rubisco amino acid residues between the two carboxysome types which could be engineered to produce a new, hybrid carboxysome. In theory, this hybrid carboxysome would benefit from the simpler α-carboxysome shell architecture while simultaneously exploiting the higher Rubisco turnover rates in β-carboxysomes. Here, we demonstrate in an Escherichia coli expression system, that the Thermosynechococcus elongatus Form IB Rubisco can be imperfectly incorporated into simplified Cyanobium α-carboxysome-like structures. While encapsulation of non-native cargo can be achieved, T. elongatus Form IB Rubisco does not interact with the Cyanobium carbonic anhydrase, a core requirement for proper carboxysome functionality. Together, these results suggest a way forward to hybrid carboxysome formation.
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Affiliation(s)
- Nghiem Dinh Nguyen
- Australian Research Council Centre of Excellence for Translational Photosynthesis, Research School of Biology, The Australian National University, Building 134, Linnaeus Way, Acton, ACT, 2601, Australia
| | - Sacha B Pulsford
- Australian Research Council Centre of Excellence in Synthetic Biology, Research School of Chemistry, The Australian National University, Building 46, Sullivan's Creek Road, Acton, ACT, 2601, Australia
| | - Wei Yi Hee
- Realizing Increased Photosynthetic Efficiency (RIPE), The Australian National University, 134 Linnaeus Way, Acton, ACT, 2601, Australia
| | - Benjamin D Rae
- Australian Research Council Centre of Excellence for Translational Photosynthesis, Research School of Biology, The Australian National University, Building 134, Linnaeus Way, Acton, ACT, 2601, Australia
| | - Loraine M Rourke
- Australian Research Council Centre of Excellence for Translational Photosynthesis, Research School of Biology, The Australian National University, Building 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, Building 134, Linnaeus Way, Acton, ACT, 2601, Australia.
- Realizing Increased Photosynthetic Efficiency (RIPE), The Australian National University, 134 Linnaeus Way, Acton, ACT, 2601, Australia.
- Division of Plant Sciences, Research School of Biology, The Australian National University, Building 134, Linnaeus Way, Canberra, ACT, 2601, Australia.
| | - Benedict M Long
- Australian Research Council Centre of Excellence for Translational Photosynthesis, Research School of Biology, The Australian National University, Building 134, Linnaeus Way, Acton, ACT, 2601, Australia
- Realizing Increased Photosynthetic Efficiency (RIPE), The Australian National University, 134 Linnaeus Way, Acton, ACT, 2601, Australia
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9
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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. JOURNAL OF EXPERIMENTAL BOTANY 2023; 74:612-626. [PMID: 35903998 DOI: 10.1093/jxb/erac321] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [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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10
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Ni T, Sun Y, Burn W, Al-Hazeem MMJ, Zhu Y, Yu X, Liu LN, Zhang P. Structure and assembly of cargo Rubisco in two native α-carboxysomes. Nat Commun 2022; 13:4299. [PMID: 35879301 PMCID: PMC9314367 DOI: 10.1038/s41467-022-32004-w] [Citation(s) in RCA: 23] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2022] [Accepted: 07/11/2022] [Indexed: 01/13/2023] Open
Abstract
Carboxysomes are a family of bacterial microcompartments in cyanobacteria and chemoautotrophs. They encapsulate Ribulose 1,5-bisphosphate carboxylase/oxygenase (Rubisco) and carbonic anhydrase catalyzing carbon fixation inside a proteinaceous shell. How Rubisco complexes pack within the carboxysomes is unknown. Using cryo-electron tomography, we determine the distinct 3D organization of Rubisco inside two distant α-carboxysomes from a marine α-cyanobacterium Cyanobium sp. PCC 7001 where Rubiscos are organized in three concentric layers, and from a chemoautotrophic bacterium Halothiobacillus neapolitanus where they form intertwining spirals. We further resolve the structures of native Rubisco as well as its higher-order assembly at near-atomic resolutions by subtomogram averaging. The structures surprisingly reveal that the authentic intrinsically disordered linker protein CsoS2 interacts with Rubiscos in native carboxysomes but functions distinctively in the two α-carboxysomes. In contrast to the uniform Rubisco-CsoS2 association in the Cyanobium α-carboxysome, CsoS2 binds only to the Rubiscos close to the shell in the Halo α-carboxysome. Our findings provide critical knowledge of the assembly principles of α-carboxysomes, which may aid in the rational design and repurposing of carboxysome structures for new functions.
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Affiliation(s)
- Tao Ni
- Division of Structural Biology, Wellcome Centre for Human Genetics, University of Oxford, Oxford, UK
| | - Yaqi Sun
- Institute of Systems, Molecular and Integrative Biology, University of Liverpool, Liverpool, UK
| | - Will Burn
- Division of Structural Biology, Wellcome Centre for Human Genetics, University of Oxford, Oxford, UK
| | - Monsour M J Al-Hazeem
- Institute of Systems, Molecular and Integrative Biology, University of Liverpool, Liverpool, UK
| | - Yanan Zhu
- Division of Structural Biology, Wellcome Centre for Human Genetics, University of Oxford, Oxford, UK
| | - Xiulian Yu
- Division of Structural Biology, Wellcome Centre for Human Genetics, University of Oxford, Oxford, 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, China.
| | - Peijun Zhang
- Division of Structural Biology, Wellcome Centre for Human Genetics, University of Oxford, Oxford, UK.
- Diamond Light Source, Harwell Science and Innovation Campus, Didcot, UK.
- Chinese Academy of Medical Sciences Oxford Institute, University of Oxford, Oxford, UK.
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11
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Tsidilkovski L, Mohajerani F, Hagan MF. Microcompartment assembly around multicomponent fluid cargoes. J Chem Phys 2022; 156:245104. [PMID: 35778087 PMCID: PMC9249432 DOI: 10.1063/5.0089556] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
This article describes dynamical simulations of the assembly of an icosahedral protein shell around a bicomponent fluid cargo. Our simulations are motivated by bacterial microcompartments, which are protein shells found in bacteria that assemble around a complex of enzymes and other components involved in certain metabolic processes. The simulations demonstrate that the relative interaction strengths among the different cargo species play a key role in determining the amount of each species that is encapsulated, their spatial organization, and the nature of the shell assembly pathways. However, the shell protein–shell protein and shell protein–cargo component interactions that help drive assembly and encapsulation also influence cargo composition within certain parameter regimes. These behaviors are governed by a combination of thermodynamic and kinetic effects. In addition to elucidating how natural microcompartments encapsulate multiple components involved within reaction cascades, these results have implications for efforts in synthetic biology to colocalize alternative sets of molecules within microcompartments to accelerate specific reactions. More broadly, the results suggest that coupling between self-assembly and multicomponent liquid–liquid phase separation may play a role in the organization of the cellular cytoplasm.
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Affiliation(s)
- Lev Tsidilkovski
- Martin A. Fisher School of Physics, Brandeis University, Waltham, Massachusetts 02453, USA
| | - Farzaneh Mohajerani
- Martin A. Fisher School of Physics, Brandeis University, Waltham, Massachusetts 02453, USA
| | - Michael F Hagan
- Martin A. Fisher School of Physics, Brandeis University, Waltham, Massachusetts 02453, USA
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12
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Getting Closer to Decrypting the Phase Transitions of Bacterial Biomolecules. Biomolecules 2022; 12:biom12070907. [PMID: 35883463 PMCID: PMC9312465 DOI: 10.3390/biom12070907] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2022] [Revised: 06/24/2022] [Accepted: 06/26/2022] [Indexed: 12/31/2022] Open
Abstract
Liquid–liquid phase separation (LLPS) of biomolecules has emerged as a new paradigm in cell biology, and the process is one proposed mechanism for the formation of membraneless organelles (MLOs). Bacterial cells have only recently drawn strong interest in terms of studies on both liquid-to-liquid and liquid-to-solid phase transitions. It seems that these processes drive the formation of prokaryotic cellular condensates that resemble eukaryotic MLOs. In this review, we present an overview of the key microbial biomolecules that undergo LLPS, as well as the formation and organization of biomacromolecular condensates within the intracellular space. We also discuss the current challenges in investigating bacterial biomacromolecular condensates. Additionally, we highlight a summary of recent knowledge about the participation of bacterial biomolecules in a phase transition and provide some new in silico analyses that can be helpful for further investigations.
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13
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Yang M, Wenner N, Dykes GF, Li Y, Zhu X, Sun Y, Huang F, Hinton JCD, Liu LN. Biogenesis of a bacterial metabolosome for propanediol utilization. Nat Commun 2022; 13:2920. [PMID: 35614058 PMCID: PMC9132943 DOI: 10.1038/s41467-022-30608-w] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2021] [Accepted: 04/22/2022] [Indexed: 12/24/2022] Open
Abstract
Bacterial metabolosomes are a family of protein organelles in bacteria. Elucidating how thousands of proteins self-assemble to form functional metabolosomes is essential for understanding their significance in cellular metabolism and pathogenesis. Here we investigate the de novo biogenesis of propanediol-utilization (Pdu) metabolosomes and characterize the roles of the key constituents in generation and intracellular positioning of functional metabolosomes. Our results demonstrate that the Pdu metabolosome undertakes both "Shell first" and "Cargo first" assembly pathways, unlike the β-carboxysome structural analog which only involves the "Cargo first" strategy. Shell and cargo assemblies occur independently at the cell poles. The internal cargo core is formed through the ordered assembly of multiple enzyme complexes, and exhibits liquid-like properties within the metabolosome architecture. Our findings provide mechanistic insight into the molecular principles driving bacterial metabolosome assembly and expand our understanding of liquid-like organelle biogenesis.
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Affiliation(s)
- Mengru Yang
- Institute of Systems, Molecular and Integrative Biology, University of Liverpool, Crown Street, Liverpool, L69 7ZB, United Kingdom
| | - Nicolas Wenner
- Institute of Infection, Veterinary & Ecological Sciences, University of Liverpool, Crown Street, Liverpool, L69 7ZB, United Kingdom
| | - Gregory F Dykes
- Institute of Systems, Molecular and Integrative Biology, University of Liverpool, Crown Street, Liverpool, L69 7ZB, United Kingdom
| | - Yan Li
- Institute of Infection, Veterinary & Ecological Sciences, University of Liverpool, Crown Street, Liverpool, L69 7ZB, United Kingdom
| | - Xiaojun Zhu
- Institute of Infection, Veterinary & Ecological Sciences, University of Liverpool, Crown Street, Liverpool, L69 7ZB, United Kingdom
| | - Yaqi Sun
- Institute of Systems, Molecular and Integrative Biology, University of Liverpool, Crown Street, Liverpool, L69 7ZB, United Kingdom
| | - Fang Huang
- Institute of Systems, Molecular and Integrative Biology, University of Liverpool, Crown Street, Liverpool, L69 7ZB, United Kingdom
| | - Jay C D Hinton
- Institute of Infection, Veterinary & Ecological Sciences, University of Liverpool, Crown Street, Liverpool, L69 7ZB, United Kingdom
| | - Lu-Ning Liu
- Institute of Systems, Molecular and Integrative Biology, University of Liverpool, Crown Street, Liverpool, L69 7ZB, United Kingdom.
- 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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14
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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] [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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15
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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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16
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Abstract
Increasing efficiency is an important driving force behind cellular organization and often achieved through compartmentalization. Long recognized as a core principle of eukaryotic cell organization, its widespread occurrence in prokaryotes has only recently come to light. Despite the early discovery of a few microcompartments such as gas vesicles and carboxysomes, the vast majority of these structures in prokaryotes are less than 100 nm in diameter - too small for conventional light microscopy and electron microscopic thin sectioning. Consequently, these smaller-sized nanocompartments have therefore been discovered serendipitously and then through bioinformatics shown to be broadly distributed. Their small uniform size, robust self-assembly, high stability, excellent biocompatibility, and large cargo capacity make them excellent candidates for biotechnology applications. This review will highlight our current knowledge of nanocompartments, the prospects for applications as well as open question and challenges that need to be addressed to fully understand these important structures.
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17
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Tan YQ, Ali S, Xue B, Teo WZ, Ling LH, Go MK, Lv H, Robinson RC, Narita A, Yew WS. Structure of a Minimal α-Carboxysome-Derived Shell and Its Utility in Enzyme Stabilization. Biomacromolecules 2021; 22:4095-4109. [PMID: 34384019 DOI: 10.1021/acs.biomac.1c00533] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Bacterial microcompartments are proteinaceous shells that encase specialized metabolic processes in bacteria. Recent advances in simplification of these intricate shells have encouraged bioengineering efforts. Here, we construct minimal shells derived from the Halothiobacillus neapolitanus α-carboxysome, which we term Cso-shell. Using cryogenic electron microscopy, the atomic-level structures of two shell forms were obtained, reinforcing notions of evolutionarily conserved features in bacterial microcompartment shell architecture. Encapsulation peptide sequences that facilitate loading of heterologous protein cargo within the shells were identified. We further provide a first demonstration in utilizing minimal bacterial microcompartment-derived shells for hosting heterologous enzymes. Cso-shells were found to stabilize enzymatic activities against heat shock, presence of methanol co-solvent, consecutive freeze-thawing, and alkaline environments. This study yields insights into α-carboxysome assembly and advances the utility of synthetic bacterial microcompartments as nanoreactors capable of stabilizing enzymes with varied properties and reaction chemistries.
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Affiliation(s)
- Yong Quan Tan
- Department of Biochemistry, Yong Loo Lin School of Medicine, National University of Singapore (NUS), 8 Medical Drive, Singapore 117597.,NUS Synthetic Biology for Clinical and Technological Innovation, 28 Medical Drive, Singapore 117456.,Graduate School for Integrative Sciences and Engineering, NUS, Singapore 119077
| | - Samson Ali
- Structural Biology Research Center, Graduate School of Science, Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8601, Japan.,Research Institute for Interdisciplinary Science (RIIS), Okayama University, 3-1-1 Tsushima-naka, Kita-ku, Okayama 700-8530, Japan
| | - Bo Xue
- Department of Biochemistry, Yong Loo Lin School of Medicine, National University of Singapore (NUS), 8 Medical Drive, Singapore 117597.,NUS Synthetic Biology for Clinical and Technological Innovation, 28 Medical Drive, Singapore 117456.,Synthetic Biology Translational Research Programme, Yong Loo Lin School of Medicine, National University of Singapore, 14 Medical Drive, Singapore 117599
| | - Wei Zhe Teo
- Department of Biochemistry, Yong Loo Lin School of Medicine, National University of Singapore (NUS), 8 Medical Drive, Singapore 117597.,NUS Synthetic Biology for Clinical and Technological Innovation, 28 Medical Drive, Singapore 117456.,Synthetic Biology Translational Research Programme, Yong Loo Lin School of Medicine, National University of Singapore, 14 Medical Drive, Singapore 117599
| | - Lay Hiang Ling
- Department of Biochemistry, Yong Loo Lin School of Medicine, National University of Singapore (NUS), 8 Medical Drive, Singapore 117597.,NUS Synthetic Biology for Clinical and Technological Innovation, 28 Medical Drive, Singapore 117456.,Graduate School for Integrative Sciences and Engineering, NUS, Singapore 119077
| | - Maybelle Kho Go
- Department of Biochemistry, Yong Loo Lin School of Medicine, National University of Singapore (NUS), 8 Medical Drive, Singapore 117597.,NUS Synthetic Biology for Clinical and Technological Innovation, 28 Medical Drive, Singapore 117456.,Synthetic Biology Translational Research Programme, Yong Loo Lin School of Medicine, National University of Singapore, 14 Medical Drive, Singapore 117599
| | - Hong Lv
- Shanghai Engineering Research Center of Industrial Microorganisms, Shanghai 200438, People's Republic of China.,State Key Laboratory of Genetic Engineering, School of Life Science, Fudan University, Shanghai 200438, People's Republic of China
| | - Robert C Robinson
- Research Institute for Interdisciplinary Science (RIIS), Okayama University, 3-1-1 Tsushima-naka, Kita-ku, Okayama 700-8530, Japan.,School of Biomolecular Science and Engineering (BSE), Vidyasirimedhi Institute of Science and Technology (VISTEC), Rayong 21210, Thailand
| | - Akihiro Narita
- Structural Biology Research Center, Graduate School of Science, Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8601, Japan
| | - Wen Shan Yew
- Department of Biochemistry, Yong Loo Lin School of Medicine, National University of Singapore (NUS), 8 Medical Drive, Singapore 117597.,NUS Synthetic Biology for Clinical and Technological Innovation, 28 Medical Drive, Singapore 117456.,Graduate School for Integrative Sciences and Engineering, NUS, Singapore 119077.,Synthetic Biology Translational Research Programme, Yong Loo Lin School of Medicine, National University of Singapore, 14 Medical Drive, Singapore 117599
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18
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Abstract
Bacterial microcompartments (BMCs) confine a diverse array of metabolic reactions within a selectively permeable protein shell, allowing for specialized biochemistry that would be less efficient or altogether impossible without compartmentalization. BMCs play critical roles in carbon fixation, carbon source utilization, and pathogenesis. Despite their prevalence and importance in bacterial metabolism, little is known about BMC “homeostasis,” a term we use here to encompass BMC assembly, composition, size, copy-number, maintenance, turnover, positioning, and ultimately, function in the cell. The carbon-fixing carboxysome is one of the most well-studied BMCs with regard to mechanisms of self-assembly and subcellular organization. In this minireview, we focus on the only known BMC positioning system to date—the maintenance of carboxysome distribution (Mcd) system, which spatially organizes carboxysomes. We describe the two-component McdAB system and its proposed diffusion-ratchet mechanism for carboxysome positioning. We then discuss the prevalence of McdAB systems among carboxysome-containing bacteria and highlight recent evidence suggesting how liquid-liquid phase separation (LLPS) may play critical roles in carboxysome homeostasis. We end with an outline of future work on the carboxysome distribution system and a perspective on how other BMCs may be spatially regulated. We anticipate that a deeper understanding of BMC organization, including nontraditional homeostasis mechanisms involving LLPS and ATP-driven organization, is on the horizon.
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19
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Sun H, Cui N, Han SJ, Chen ZP, Xia LY, Chen Y, Jiang YL, Zhou CZ. Complex structure reveals CcmM and CcmN form a heterotrimeric adaptor in β-carboxysome. Protein Sci 2021; 30:1566-1576. [PMID: 33928692 DOI: 10.1002/pro.4090] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2021] [Revised: 04/14/2021] [Accepted: 04/22/2021] [Indexed: 11/09/2022]
Abstract
Carboxysome is an icosahedral self-assembled microcompartment that sequesters RuBisCO and carbonic anhydrases within a selectively permeable protein shell. The scaffolding proteins, CcmM, and CcmN were proposed to act as adaptors that crosslink the enzymatic core to shell facets. However, the details of interaction pattern remain unknown. Here we obtained a stable heterotrimeric complex of CcmM γ-carbonic anhydrase domain (termed CcmMNT ) and CcmN, with a 1:2 stoichiometry, which interacts with the shell proteins CcmO and CcmL in vitro. The 2.9 Å crystal structure of this heterotrimer revealed an asymmetric bundle composed of one CcmMNT and two CcmN subunits, all of which adopt a triangular left-handed β-helical barrel structure. The central CcmN subunit packs against CcmMNT and another CcmN subunit via a wall-to-edge or wall-to-wall pattern, respectively. Together with previous findings, we propose CcmMNT -CcmN functions as an adaptor to facilitate the recruitment of shell proteins and the assembly of intact β-carboxysome.
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Affiliation(s)
- Hui Sun
- Hefei National Laboratory for Physical Sciences at the Microscale and School of Life Sciences, University of Science and Technology of China, Hefei, China
| | - Ning Cui
- Hefei National Laboratory for Physical Sciences at the Microscale and School of Life Sciences, University of Science and Technology of China, Hefei, China
| | - Shu-Jing Han
- Hefei National Laboratory for Physical Sciences at the Microscale and School of Life Sciences, University of Science and Technology of China, Hefei, China
| | - Zhi-Peng Chen
- Hefei National Laboratory for Physical Sciences at the Microscale and School of Life Sciences, University of Science and Technology of China, Hefei, China
| | - Ling-Yun Xia
- Hefei National Laboratory for Physical Sciences at the Microscale and School of Life Sciences, University of Science and Technology of China, Hefei, China
| | - Yuxing Chen
- Hefei National Laboratory for Physical Sciences at the Microscale and School of Life Sciences, University of Science and Technology of China, Hefei, China
| | - Yong-Liang Jiang
- Hefei National Laboratory for Physical Sciences at the Microscale and School of Life Sciences, University of Science and Technology of China, Hefei, China
| | - Cong-Zhao Zhou
- Hefei National Laboratory for Physical Sciences at the Microscale and School of Life Sciences, University of Science and Technology of China, Hefei, China
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20
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Cesle EE, Filimonenko A, Tars K, Kalnins G. Variety of size and form of GRM2 bacterial microcompartment particles. Protein Sci 2021; 30:1035-1043. [PMID: 33763934 PMCID: PMC8040866 DOI: 10.1002/pro.4069] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2021] [Accepted: 03/23/2021] [Indexed: 12/12/2022]
Abstract
Bacterial microcompartments (BMCs) are bacterial organelles involved in enzymatic processes, such as carbon fixation, choline, ethanolamine and propanediol degradation, and others. Formed of a semi-permeable protein shell and an enzymatic core, they can enhance enzyme performance and protect the cell from harmful intermediates. With the ability to encapsulate non-native enzymes, BMCs show high potential for applied use. For this goal, a detailed look into shell form variability is significant to predict shell adaptability. Here we present four novel 3D cryo-EM maps of recombinant Klebsiella pneumoniae GRM2 BMC shell particles with the resolution in range of 9 to 22 Å and nine novel 2D classes corresponding to discrete BMC shell forms. These structures reveal icosahedral, elongated, oblate, multi-layered and polyhedral traits of BMCs, indicating considerable variation in size and form as well as adaptability during shell formation processes.
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Affiliation(s)
- Eva Emilija Cesle
- Structural Biology, Biotechnology and Virusology LaboratoryLatvian Biomedical Research and Study CentreRigaLatvia
| | - Anatolij Filimonenko
- CEITEC‐Central European Institute of TechnologyMasaryk UniversityBrnoCzech Republic
| | - Kaspars Tars
- Structural Biology, Biotechnology and Virusology LaboratoryLatvian Biomedical Research and Study CentreRigaLatvia
- Faculty of BiologyUniversity of LatviaRigaLatvia
| | - Gints Kalnins
- Structural Biology, Biotechnology and Virusology LaboratoryLatvian Biomedical Research and Study CentreRigaLatvia
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21
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Rubisco proton production can drive the elevation of CO 2 within condensates and carboxysomes. Proc Natl Acad Sci U S A 2021; 118:2014406118. [PMID: 33931502 PMCID: PMC8106323 DOI: 10.1073/pnas.2014406118] [Citation(s) in RCA: 33] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
Membraneless organelles containing the enzyme ribulose-1,5-bisphosphate carboxylase/oxygenase (Rubisco) are a common feature of organisms utilizing CO2 concentrating mechanisms to enhance photosynthetic carbon acquisition. In cyanobacteria and proteobacteria, the Rubisco condensate is encapsulated in a proteinaceous shell, collectively termed a carboxysome, while some algae and hornworts have evolved Rubisco condensates known as pyrenoids. In both cases, CO2 fixation is enhanced compared with the free enzyme. Previous mathematical models have attributed the improved function of carboxysomes to the generation of elevated CO2 within the organelle via a colocalized carbonic anhydrase (CA) and inwardly diffusing HCO3 -, which have accumulated in the cytoplasm via dedicated transporters. Here, we present a concept in which we consider the net of two protons produced in every Rubisco carboxylase reaction. We evaluate this in a reaction-diffusion compartment model to investigate functional advantages these protons may provide Rubisco condensates and carboxysomes, prior to the evolution of HCO3 - accumulation. Our model highlights that diffusional resistance to reaction species within a condensate allows Rubisco-derived protons to drive the conversion of HCO3 - to CO2 via colocalized CA, enhancing both condensate [CO2] and Rubisco rate. Protonation of Rubisco substrate (RuBP) and product (phosphoglycerate) plays an important role in modulating internal pH and CO2 generation. Application of the model to putative evolutionary ancestors, prior to contemporary cellular HCO3 - accumulation, revealed photosynthetic enhancements along a logical sequence of advancements, via Rubisco condensation, to fully formed carboxysomes. Our model suggests that evolution of Rubisco condensation could be favored under low CO2 and low light environments.
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22
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Azaldegui CA, Vecchiarelli AG, Biteen JS. The emergence of phase separation as an organizing principle in bacteria. Biophys J 2021; 120:1123-1138. [PMID: 33186556 PMCID: PMC8059088 DOI: 10.1016/j.bpj.2020.09.023] [Citation(s) in RCA: 101] [Impact Index Per Article: 33.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2020] [Revised: 09/10/2020] [Accepted: 09/15/2020] [Indexed: 12/12/2022] Open
Abstract
Recent investigations in bacteria suggest that membraneless organelles play a crucial role in the subcellular organization of bacterial cells. However, the biochemical functions and assembly mechanisms of these compartments have not yet been completely characterized. This article assesses the current methodologies used in the study of membraneless organelles in bacteria, highlights the limitations in determining the phase of complexes in cells that are typically an order of magnitude smaller than a eukaryotic cell, and identifies gaps in our current knowledge about the functional role of membraneless organelles in bacteria. Liquid-liquid phase separation (LLPS) is one proposed mechanism for membraneless organelle assembly. Overall, we outline the framework to evaluate LLPS in vivo in bacteria, we describe the bacterial systems with proposed LLPS activity, and we comment on the general role LLPS plays in bacteria and how it may regulate cellular function. Lastly, we provide an outlook for super-resolution microscopy and single-molecule tracking as tools to assess condensates in bacteria.
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Affiliation(s)
| | - Anthony G Vecchiarelli
- Department of Molecular, Cellular, and Developmental Biology, University of Michigan, Ann Arbor, Michigan.
| | - Julie S Biteen
- Department of Chemistry, University of Michigan, Ann Arbor, Michigan.
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23
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Barrett J, Girr P, Mackinder LCM. Pyrenoids: CO 2-fixing phase separated liquid organelles. BIOCHIMICA ET BIOPHYSICA ACTA. MOLECULAR CELL RESEARCH 2021; 1868:118949. [PMID: 33421532 DOI: 10.1016/j.bbamcr.2021.118949] [Citation(s) in RCA: 37] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/14/2020] [Revised: 12/11/2020] [Accepted: 12/12/2020] [Indexed: 02/06/2023]
Abstract
Pyrenoids are non-membrane bound organelles found in chloroplasts of algae and hornwort plants that can be seen by light-microscopy. Pyrenoids are formed by liquid-liquid phase separation (LLPS) of Rubisco, the primary CO2 fixing enzyme, with an intrinsically disordered multivalent Rubisco-binding protein. Pyrenoids are the heart of algal and hornwort biophysical CO2 concentrating mechanisms, which accelerate photosynthesis and mediate about 30% of global carbon fixation. Even though LLPS may underlie the apparent convergent evolution of pyrenoids, our current molecular understanding of pyrenoid formation comes from a single example, the model alga Chlamydomonas reinhardtii. In this review, we summarise current knowledge about pyrenoid assembly, regulation and structural organization in Chlamydomonas and highlight evidence that LLPS is the general principle underlying pyrenoid formation across algal lineages and hornworts. Detailed understanding of the principles behind pyrenoid assembly, regulation and structural organization within diverse lineages will provide a fundamental understanding of this biogeochemically important organelle and help guide ongoing efforts to engineer pyrenoids into crops to increase photosynthetic performance and yields.2.
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Affiliation(s)
- James Barrett
- Department of Biology, University of York, York YO10 5DD, UK
| | - Philipp Girr
- Department of Biology, University of York, York YO10 5DD, UK
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24
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Mohajerani F, Sayer E, Neil C, Inlow K, Hagan MF. Mechanisms of Scaffold-Mediated Microcompartment Assembly and Size Control. ACS NANO 2021; 15:4197-4212. [PMID: 33683101 PMCID: PMC8058603 DOI: 10.1021/acsnano.0c05715] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
This article describes a theoretical and computational study of the dynamical assembly of a protein shell around a complex consisting of many cargo molecules and long, flexible scaffold molecules. Our study is motivated by bacterial microcompartments, which are proteinaceous organelles that assemble around a condensed droplet of enzymes and reactants. As in many examples of cytoplasmic liquid-liquid phase separation, condensation of the microcompartment interior cargo is driven by flexible scaffold proteins that have weak multivalent interactions with the cargo. Our results predict that the shell size, amount of encapsulated cargo, and assembly pathways depend sensitively on properties of the scaffold, including its length and valency of scaffold-cargo interactions. Moreover, the ability of self-assembling protein shells to change their size to accommodate scaffold molecules of different lengths depends crucially on whether the spontaneous curvature radius of the protein shell is smaller or larger than a characteristic elastic length scale of the shell. Beyond natural microcompartments, these results have important implications for synthetic biology efforts to target alternative molecules for encapsulation by microcompartments or viral shells. More broadly, the results elucidate how cells exploit coupling between self-assembly and liquid-liquid phase separation to organize their interiors.
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Affiliation(s)
- Farzaneh Mohajerani
- Martin A. Fisher School of Physics, Brandeis University, Waltham, Massachusetts 02453, United States
| | - Evan Sayer
- Martin A. Fisher School of Physics, Brandeis University, Waltham, Massachusetts 02453, United States
| | - Christopher Neil
- Department of Biochemistry, Brandeis University, Waltham, Massachusetts 02453, United States
| | - Koe Inlow
- Department of Biochemistry, Brandeis University, Waltham, Massachusetts 02453, United States
| | - Michael F Hagan
- Martin A. Fisher School of Physics, Brandeis University, Waltham, Massachusetts 02453, United States
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25
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MacCready JS, Basalla JL, Vecchiarelli AG. Origin and Evolution of Carboxysome Positioning Systems in Cyanobacteria. Mol Biol Evol 2021; 37:1434-1451. [PMID: 31899489 PMCID: PMC7182216 DOI: 10.1093/molbev/msz308] [Citation(s) in RCA: 35] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Carboxysomes are protein-based organelles that are essential for allowing cyanobacteria to fix CO2. Previously, we identified a two-component system, McdAB, responsible for equidistantly positioning carboxysomes in the model cyanobacterium Synechococcus elongatus PCC 7942 (MacCready JS, Hakim P, Young EJ, Hu L, Liu J, Osteryoung KW, Vecchiarelli AG, Ducat DC. 2018. Protein gradients on the nucleoid position the carbon-fixing organelles of cyanobacteria. eLife 7:pii:e39723). McdA, a ParA-type ATPase, nonspecifically binds the nucleoid in the presence of ATP. McdB, a novel factor that directly binds carboxysomes, displaces McdA from the nucleoid. Removal of McdA from the nucleoid in the vicinity of carboxysomes by McdB causes a global break in McdA symmetry, and carboxysome motion occurs via a Brownian-ratchet-based mechanism toward the highest concentration of McdA. Despite the importance for cyanobacteria to properly position their carboxysomes, whether the McdAB system is widespread among cyanobacteria remains an open question. Here, we show that the McdAB system is widespread among β-cyanobacteria, often clustering with carboxysome-related components, and is absent in α-cyanobacteria. Moreover, we show that two distinct McdAB systems exist in β-cyanobacteria, with Type 2 systems being the most ancestral and abundant, and Type 1 systems, like that of S. elongatus, possibly being acquired more recently. Lastly, all McdB proteins share the sequence signatures of a protein capable of undergoing liquid–liquid phase separation. Indeed, we find that representatives of both McdB types undergo liquid–liquid phase separation in vitro, the first example of a ParA-type ATPase partner protein to exhibit this behavior. Our results have broader implications for understanding carboxysome evolution, biogenesis, homeostasis, and positioning in cyanobacteria.
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Affiliation(s)
- Joshua S MacCready
- Department of Molecular, Cellular, and Developmental Biology, University of Michigan, Ann Arbor, MI
| | - Joseph L Basalla
- Department of Molecular, Cellular, and Developmental Biology, University of Michigan, Ann Arbor, MI
| | - Anthony G Vecchiarelli
- Department of Molecular, Cellular, and Developmental Biology, University of Michigan, Ann Arbor, MI
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26
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He S, Chou HT, Matthies D, Wunder T, Meyer MT, Atkinson N, Martinez-Sanchez A, Jeffrey PD, Port SA, Patena W, He G, Chen VK, Hughson FM, McCormick AJ, Mueller-Cajar O, Engel BD, Yu Z, Jonikas MC. The structural basis of Rubisco phase separation in the pyrenoid. NATURE PLANTS 2020; 6:1480-1490. [PMID: 33230314 PMCID: PMC7736253 DOI: 10.1038/s41477-020-00811-y] [Citation(s) in RCA: 50] [Impact Index Per Article: 12.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/01/2020] [Accepted: 10/21/2020] [Indexed: 05/04/2023]
Abstract
Approximately one-third of global CO2 fixation occurs in a phase-separated algal organelle called the pyrenoid. The existing data suggest that the pyrenoid forms by the phase separation of the CO2-fixing enzyme Rubisco with a linker protein; however, the molecular interactions underlying this phase separation remain unknown. Here we present the structural basis of the interactions between Rubisco and its intrinsically disordered linker protein Essential Pyrenoid Component 1 (EPYC1) in the model alga Chlamydomonas reinhardtii. We find that EPYC1 consists of five evenly spaced Rubisco-binding regions that share sequence similarity. Single-particle cryo-electron microscopy of these regions in complex with Rubisco indicates that each Rubisco holoenzyme has eight binding sites for EPYC1, one on each Rubisco small subunit. Interface mutations disrupt binding, phase separation and pyrenoid formation. Cryo-electron tomography supports a model in which EPYC1 and Rubisco form a codependent multivalent network of specific low-affinity bonds, giving the matrix liquid-like properties. Our results advance the structural and functional understanding of the phase separation underlying the pyrenoid, an organelle that plays a fundamental role in the global carbon cycle.
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Affiliation(s)
- Shan He
- Department of Molecular Biology, Princeton University, Princeton, NJ, USA
| | - Hui-Ting Chou
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, VA, USA
- Department of Therapeutic Discovery, Amgen Discovery Research, Amgen Inc., South San Francisco, CA, USA
| | - Doreen Matthies
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, VA, USA
| | - Tobias Wunder
- School of Biological Sciences, Nanyang Technological University, Singapore, Singapore
| | - Moritz T Meyer
- Department of Molecular Biology, Princeton University, Princeton, NJ, USA
| | - Nicky Atkinson
- SynthSys & Institute of Molecular Plant Sciences, School of Biological Sciences, University of Edinburgh, Edinburgh, UK
| | - Antonio Martinez-Sanchez
- Department of Molecular Structural Biology, Max Planck Institute of Biochemistry, Martinsried, Germany
- Institute of Neuropathology, University of Göttingen Medical Center, Göttingen, Germany
| | - Philip D Jeffrey
- Department of Molecular Biology, Princeton University, Princeton, NJ, USA
| | - Sarah A Port
- Department of Molecular Biology, Princeton University, Princeton, NJ, USA
| | - Weronika Patena
- Department of Molecular Biology, Princeton University, Princeton, NJ, USA
| | - Guanhua He
- Department of Molecular Biology, Princeton University, Princeton, NJ, USA
| | - Vivian K Chen
- Department of Biology, Stanford University, Stanford, CA, USA
| | | | - Alistair J McCormick
- SynthSys & Institute of Molecular Plant Sciences, School of Biological Sciences, University of Edinburgh, Edinburgh, UK
| | - Oliver Mueller-Cajar
- School of Biological Sciences, Nanyang Technological University, Singapore, Singapore
| | - Benjamin D Engel
- Department of Molecular Structural Biology, Max Planck Institute of Biochemistry, Martinsried, Germany
- Helmholtz Pioneer Campus, Helmholtz Zentrum München, Neuherberg, Germany
- Department of Chemistry, Technical University of Munich, Garching, Germany
| | - Zhiheng Yu
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, VA, USA
| | - Martin C Jonikas
- Department of Molecular Biology, Princeton University, Princeton, NJ, USA.
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27
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Reprogramming bacterial protein organelles as a nanoreactor for hydrogen production. Nat Commun 2020; 11:5448. [PMID: 33116131 PMCID: PMC7595155 DOI: 10.1038/s41467-020-19280-0] [Citation(s) in RCA: 54] [Impact Index Per Article: 13.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2020] [Accepted: 10/07/2020] [Indexed: 11/30/2022] Open
Abstract
Compartmentalization is a ubiquitous building principle in cells, which permits segregation of biological elements and reactions. The carboxysome is a specialized bacterial organelle that encapsulates enzymes into a virus-like protein shell and plays essential roles in photosynthetic carbon fixation. The naturally designed architecture, semi-permeability, and catalytic improvement of carboxysomes have inspired rational design and engineering of new nanomaterials to incorporate desired enzymes into the protein shell for enhanced catalytic performance. Here, we build large, intact carboxysome shells (over 90 nm in diameter) in the industrial microorganism Escherichia coli by expressing a set of carboxysome protein-encoding genes. We develop strategies for enzyme activation, shell self-assembly, and cargo encapsulation to construct a robust nanoreactor that incorporates catalytically active [FeFe]-hydrogenases and functional partners within the empty shell for the production of hydrogen. We show that shell encapsulation and the internal microenvironment of the new catalyst facilitate hydrogen production of the encapsulated oxygen-sensitive hydrogenases. The study provides insights into the assembly and formation of carboxysomes and paves the way for engineering carboxysome shell-based nanoreactors to recruit specific enzymes for diverse catalytic reactions. The extreme oxygen sensitive character of hydrogenases is a longstanding issue for hydrogen production in bacteria. Here, the authors build carboxysome shells in E. coli and incorporate catalytically active hydrogenases and functional partners within the empty shell for the production of hydrogen.
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28
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Veaudor T, Blanc-Garin V, Chenebault C, Diaz-Santos E, Sassi JF, Cassier-Chauvat C, Chauvat F. Recent Advances in the Photoautotrophic Metabolism of Cyanobacteria: Biotechnological Implications. Life (Basel) 2020; 10:life10050071. [PMID: 32438704 PMCID: PMC7281370 DOI: 10.3390/life10050071] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2020] [Revised: 05/16/2020] [Accepted: 05/18/2020] [Indexed: 12/13/2022] Open
Abstract
Cyanobacteria constitute the only phylum of oxygen-evolving photosynthetic prokaryotes that shaped the oxygenic atmosphere of our planet. Over time, cyanobacteria have evolved as a widely diverse group of organisms that have colonized most aquatic and soil ecosystems of our planet and constitute a large proportion of the biomass that sustains the biosphere. Cyanobacteria synthesize a vast array of biologically active metabolites that are of great interest for human health and industry, and several model cyanobacteria can be genetically manipulated. Hence, cyanobacteria are regarded as promising microbial factories for the production of chemicals from highly abundant natural resources, e.g., solar energy, CO2, minerals, and waters, eventually coupled to wastewater treatment to save costs. In this review, we summarize new important discoveries on the plasticity of the photoautotrophic metabolism of cyanobacteria, emphasizing the coordinated partitioning of carbon and nitrogen towards growth or compound storage, and the importance of these processes for biotechnological perspectives. We also emphasize the importance of redox regulation (including glutathionylation) on these processes, a subject which has often been overlooked.
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Affiliation(s)
- Théo Veaudor
- Institute for Integrative Biology of the Cell (I2BC), Université Paris-Saclay, CEA, CNRS, 91198 Gif-sur-Yvette, France; (T.V.); (V.B.-G.); (C.C.); (E.D.-S.); (C.C.-C.)
| | - Victoire Blanc-Garin
- Institute for Integrative Biology of the Cell (I2BC), Université Paris-Saclay, CEA, CNRS, 91198 Gif-sur-Yvette, France; (T.V.); (V.B.-G.); (C.C.); (E.D.-S.); (C.C.-C.)
| | - Célia Chenebault
- Institute for Integrative Biology of the Cell (I2BC), Université Paris-Saclay, CEA, CNRS, 91198 Gif-sur-Yvette, France; (T.V.); (V.B.-G.); (C.C.); (E.D.-S.); (C.C.-C.)
| | - Encarnación Diaz-Santos
- Institute for Integrative Biology of the Cell (I2BC), Université Paris-Saclay, CEA, CNRS, 91198 Gif-sur-Yvette, France; (T.V.); (V.B.-G.); (C.C.); (E.D.-S.); (C.C.-C.)
| | - Jean-François Sassi
- Commissariat à l’énergie atomique et aux énergies alternatives (CEA), Centre de Cadarache St Paul Lez, 13108 Durance, France;
| | - Corinne Cassier-Chauvat
- Institute for Integrative Biology of the Cell (I2BC), Université Paris-Saclay, CEA, CNRS, 91198 Gif-sur-Yvette, France; (T.V.); (V.B.-G.); (C.C.); (E.D.-S.); (C.C.-C.)
| | - Franck Chauvat
- Institute for Integrative Biology of the Cell (I2BC), Université Paris-Saclay, CEA, CNRS, 91198 Gif-sur-Yvette, France; (T.V.); (V.B.-G.); (C.C.); (E.D.-S.); (C.C.-C.)
- Correspondence: ; Tel.: +33-1-69-08-78-11
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29
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Hennacy JH, Jonikas MC. Prospects for Engineering Biophysical CO 2 Concentrating Mechanisms into Land Plants to Enhance Yields. ANNUAL REVIEW OF PLANT BIOLOGY 2020; 71:461-485. [PMID: 32151155 PMCID: PMC7845915 DOI: 10.1146/annurev-arplant-081519-040100] [Citation(s) in RCA: 72] [Impact Index Per Article: 18.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/06/2023]
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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30
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Juodeikis R, Lee MJ, Mayer M, Mantell J, Brown IR, Verkade P, Woolfson DN, Prentice MB, Frank S, Warren MJ. Effect of metabolosome encapsulation peptides on enzyme activity, coaggregation, incorporation, and bacterial microcompartment formation. Microbiologyopen 2020; 9:e1010. [PMID: 32053746 PMCID: PMC7221423 DOI: 10.1002/mbo3.1010] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2019] [Revised: 01/17/2020] [Accepted: 01/21/2020] [Indexed: 01/21/2023] Open
Abstract
Metabolosomes, catabolic bacterial microcompartments (BMCs), are proteinaceous organelles that are associated with the breakdown of metabolites such as propanediol and ethanolamine. They are composed of an outer multicomponent protein shell that encases a specific metabolic pathway. Protein cargo found within BMCs is directed by the presence of an encapsulation peptide that appears to trigger aggregation before the formation of the outer shell. We investigated the effect of three distinct encapsulation peptides on foreign cargo in a recombinant BMC system. Our data demonstrate that these peptides cause variations in enzyme activity and protein aggregation. We observed that the level of protein aggregation generally correlates with the size of metabolosomes, while in the absence of cargo BMCs self‐assemble into smaller compartments. The results agree with a flexible model for BMC formation based around the ability of the BMC shell to associate with an aggregate formed due to the interaction of encapsulation peptides.
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Affiliation(s)
- Rokas Juodeikis
- Centre for Industrial Biotechnology, School of Biosciences, University of Kent, Canterbury, UK
| | - Matthew J Lee
- Centre for Industrial Biotechnology, School of Biosciences, University of Kent, Canterbury, UK
| | - Matthias Mayer
- Centre for Industrial Biotechnology, School of Biosciences, University of Kent, Canterbury, UK
| | - Judith Mantell
- School of Biochemistry, University of Bristol, Bristol, UK.,Wolfson Bioimaging Facility, University of Bristol, Bristol, UK
| | - Ian R Brown
- Centre for Industrial Biotechnology, School of Biosciences, University of Kent, Canterbury, UK
| | - Paul Verkade
- School of Biochemistry, University of Bristol, Bristol, UK.,Wolfson Bioimaging Facility, University of Bristol, Bristol, UK.,BrisSynBio, University of Bristol, Bristol, UK
| | - Derek N Woolfson
- School of Biochemistry, University of Bristol, Bristol, UK.,BrisSynBio, University of Bristol, Bristol, UK.,School of Chemistry, University of Bristol, Bristol, UK
| | | | - Stefanie Frank
- Department of Biochemical Engineering, University College London, London, UK
| | - Martin J Warren
- Centre for Industrial Biotechnology, School of Biosciences, University of Kent, Canterbury, UK
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31
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Orr DJ, Worrall D, Lin MT, Carmo-Silva E, Hanson MR, Parry MAJ. Hybrid Cyanobacterial-Tobacco Rubisco Supports Autotrophic Growth and Procarboxysomal Aggregation. PLANT PHYSIOLOGY 2020; 182:807-818. [PMID: 31744936 PMCID: PMC6997680 DOI: 10.1104/pp.19.01193] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/27/2019] [Accepted: 11/05/2019] [Indexed: 05/22/2023]
Abstract
Much of the research aimed at improving photosynthesis and crop productivity attempts to overcome shortcomings of the primary CO2-fixing enzyme Rubisco. Cyanobacteria utilize a CO2-concentrating mechanism (CCM), which encapsulates Rubisco with poor specificity but a relatively fast catalytic rate within a carboxysome microcompartment. Alongside the active transport of bicarbonate into the cell and localization of carbonic anhydrase within the carboxysome shell with Rubisco, cyanobacteria are able to overcome the limitations of Rubisco via localization within a high-CO2 environment. As part of ongoing efforts to engineer a β-cyanobacterial CCM into land plants, we investigated the potential for Rubisco large subunits (LSU) from the β-cyanobacterium Synechococcus elongatus (Se) to form aggregated Rubisco complexes with the carboxysome linker protein CcmM35 within tobacco (Nicotiana tabacum) chloroplasts. Transplastomic plants were produced that lacked cognate Se Rubisco small subunits (SSU) and expressed the Se LSU in place of tobacco LSU, with and without CcmM35. Plants were able to form a hybrid enzyme utilizing tobacco SSU and the Se LSU, allowing slow autotrophic growth in high CO2 CcmM35 was able to form large Rubisco aggregates with the Se LSU, and these incorporated small amounts of native tobacco SSU. Plants lacking the Se SSU showed delayed growth, poor photosynthetic capacity, and significantly reduced Rubisco activity compared with both wild-type tobacco and lines expressing the Se SSU. These results demonstrate the ability of the Se LSU and CcmM35 to form large aggregates without the cognate Se SSU in planta, harboring active Rubisco that enables plant growth, albeit at a much slower pace than plants expressing the cognate Se SSU.
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Affiliation(s)
- Douglas J Orr
- Lancaster Environment Centre, Lancaster University, Lancaster LA1 4YQ, United Kingdom
| | - Dawn Worrall
- Lancaster Environment Centre, Lancaster University, Lancaster LA1 4YQ, United Kingdom
| | - Myat T Lin
- Department of Molecular Biology and Genetics, Cornell University, Ithaca, New York 14850
| | - Elizabete Carmo-Silva
- Lancaster Environment Centre, Lancaster University, Lancaster LA1 4YQ, United Kingdom
| | - Maureen R Hanson
- Department of Molecular Biology and Genetics, Cornell University, Ithaca, New York 14850
| | - Martin A J Parry
- Lancaster Environment Centre, Lancaster University, Lancaster LA1 4YQ, United Kingdom
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32
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Kirst H, Kerfeld CA. Bacterial microcompartments: catalysis-enhancing metabolic modules for next generation metabolic and biomedical engineering. BMC Biol 2019; 17:79. [PMID: 31601225 PMCID: PMC6787980 DOI: 10.1186/s12915-019-0691-z] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2019] [Accepted: 08/23/2019] [Indexed: 12/15/2022] Open
Abstract
Bacterial cells have long been thought to be simple cells with little spatial organization, but recent research has shown that they exhibit a remarkable degree of subcellular differentiation. Indeed, bacteria even have organelles such as magnetosomes for sensing magnetic fields or gas vesicles controlling cell buoyancy. A functionally diverse group of bacterial organelles are the bacterial microcompartments (BMCs) that fulfill specialized metabolic needs. Modification and reengineering of these BMCs enable innovative approaches for metabolic engineering and nanomedicine.
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Affiliation(s)
- Henning Kirst
- MSU-DOE Plant Research Laboratory, Michigan State University, 612 Wilson Road, East Lansing, MI, 48824, USA.,Environmental Genomics and Systems Biology and Molecular Biophysics and Integrated Bioimaging Divisions, Lawrence Berkeley National Laboratory, 1 Cyclotron Road, Berkeley, CA, 94720, USA
| | - Cheryl A Kerfeld
- MSU-DOE Plant Research Laboratory, Michigan State University, 612 Wilson Road, East Lansing, MI, 48824, USA. .,Environmental Genomics and Systems Biology and Molecular Biophysics and Integrated Bioimaging Divisions, 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.
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33
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Li YY, Chen XH, Xue C, Zhang H, Sun G, Xie ZX, Lin L, Wang DZ. Proteomic Response to Rising Temperature in the Marine Cyanobacterium Synechococcus Grown in Different Nitrogen Sources. Front Microbiol 2019; 10:1976. [PMID: 31507578 PMCID: PMC6716455 DOI: 10.3389/fmicb.2019.01976] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2019] [Accepted: 08/12/2019] [Indexed: 11/16/2022] Open
Abstract
Synechococcus is one of the most important contributors to global primary productivity, and ocean warming is predicted to increase abundance and distribution of Synechococcus in the ocean. Here, we investigated molecular response of an oceanic Synechococcus strain WH8102 grown in two nitrogen sources (nitrate and urea) under present (25°C) and predicted future (28°C) temperature conditions using an isobaric tag (IBT)-based quantitative proteomic approach. Rising temperature decreased growth rate, contents of chlorophyll a, protein and sugar in the nitrate-grown cells, but only decreased protein content and significantly increased zeaxanthin content of the urea-grown cells. Expressions of CsoS2 protein involved in carboxysome formation and ribosomal subunits in both nitrate- and urea-grown cells were significantly decreased in rising temperature, whereas carbohydrate selective porin and sucrose-phosphate synthase (SPS) were remarkably up-regulated, and carbohydrate degradation associated proteins, i.e., glycogen phosphorylase kinase, fructokinase and glucose-6-phosphate dehydrogenase, were down-regulated in the urea-grown cells. Rising temperature also increased expressions of three redox-sensitive enzymes (peroxiredoxin, thioredoxin, and CP12) in both nitrate- and urea-grown cells. Our results indicated that rising temperature did not enhance cell growth of Synechococcus; on the contrary, it impaired cell functions, and this might influence cell abundance and distribution of Synechococcus in a future ocean.
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Affiliation(s)
- Yuan-Yuan Li
- State Key Laboratory of Marine Environmental Science, College of the Environment and Ecology, Xiamen University, Xiamen, China
| | - Xiao-Huang Chen
- State Key Laboratory of Marine Environmental Science, College of the Environment and Ecology, Xiamen University, Xiamen, China
| | - Cheng Xue
- State Key Laboratory of Marine Environmental Science, College of the Environment and Ecology, Xiamen University, Xiamen, China
| | - Hao Zhang
- State Key Laboratory of Marine Environmental Science, College of the Environment and Ecology, Xiamen University, Xiamen, China
| | - Geng Sun
- State Key Laboratory of Marine Environmental Science, College of the Environment and Ecology, Xiamen University, Xiamen, China
| | - Zhang-Xian Xie
- State Key Laboratory of Marine Environmental Science, College of the Environment and Ecology, Xiamen University, Xiamen, China
| | - Lin Lin
- State Key Laboratory of Marine Environmental Science, College of the Environment and Ecology, Xiamen University, Xiamen, China
| | - Da-Zhi Wang
- State Key Laboratory of Marine Environmental Science, College of the Environment and Ecology, Xiamen University, Xiamen, China
- Key Laboratory of Marine Ecology and Environmental Sciences, Chinese Academy of Sciences, Qingdao, China
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34
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Bio-engineering of bacterial microcompartments: a mini review. Biochem Soc Trans 2019; 47:765-777. [DOI: 10.1042/bst20170564] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2019] [Revised: 05/09/2019] [Accepted: 05/22/2019] [Indexed: 12/30/2022]
Abstract
AbstractBacterial microcompartments (BMCs) are protein-bound prokaryotic organelles, discovered in cyanobacteria more than 60 years ago. Functionally similar to eukaryotic cellular organelles, BMCs compartment metabolic activities in the cytoplasm, foremost to increase local enzyme concentration and prevent toxic intermediates from damaging the cytosolic content. Advanced knowledge of the functional and structural properties of multiple types of BMCs, particularly over the last 10 years, have highlighted design principles of microcompartments. This has prompted new research into their potential to function as programmable synthetic nano-bioreactors and novel bio-materials with biotechnological and medical applications. Moreover, due to the involvement of microcompartments in bacterial pathogenesis and human health, BMCs have begun to gain attention as potential novel drug targets. This mini-review gives an overview of important synthetic biology developments in the bioengineering of BMCs and a perspective on future directions in the field.
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35
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Dai W, Chen M, Myers C, Ludtke SJ, Pettitt BM, King JA, Schmid MF, Chiu W. Visualizing Individual RuBisCO and Its Assembly into Carboxysomes in Marine Cyanobacteria by Cryo-Electron Tomography. J Mol Biol 2018; 430:4156-4167. [PMID: 30138616 DOI: 10.1016/j.jmb.2018.08.013.visualizing] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2018] [Revised: 07/29/2018] [Accepted: 08/13/2018] [Indexed: 05/19/2023]
Abstract
Cyanobacteria are photosynthetic organisms responsible for ~25% of the organic carbon fixation on earth. A key step in carbon fixation is catalyzed by ribulose bisphosphate carboxylase/oxygenase (RuBisCO), the most abundant enzyme in the biosphere. Applying Zernike phase-contrast electron cryo-tomography and automated annotation, we identified individual RuBisCO molecules and their assembly intermediates leading to the formation of carboxysomes inside Syn5 cyanophage infected cyanobacteria Synechococcus sp. WH8109 cells. Surprisingly, more RuBisCO molecules were found to be present as cytosolic free-standing complexes or clusters than as packaged assemblies inside carboxysomes. Cytosolic RuBisCO clusters and partially assembled carboxysomes identified in the cell tomograms support a concurrent assembly model involving both the protein shell and the enclosed RuBisCO. In mature carboxysomes, RuBisCO is neither randomly nor strictly icosahedrally packed within protein shells of variable sizes. A time-averaged molecular dynamics simulation showed a semi-liquid probability distribution of the RuBisCO in carboxysomes and correlated well with carboxysome subtomogram averages. Our structural observations reveal the various stages of RuBisCO assemblies, which could be important for understanding cellular function.
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Affiliation(s)
- Wei Dai
- Department of Cell Biology and Neuroscience & Institute for Quantitative Biomedicine, Rutgers University, Piscataway, NJ 08854, USA.
| | - Muyuan Chen
- Verna and Marrs Mclean Department of Biochemistry and Molecular Biology, Baylor College of Medicine, Houston, TX 77030, USA
| | - Christopher Myers
- Department of Pharmacology and Toxicology, University of Texas Medical Branch, Galveston, TX 77555, USA; Department of Biochemistry and Molecular Biology, University of Texas Medical Branch, Galveston, TX 77555, USA; Sealy Center for Structural Biology and Molecular Biophysics, University of Texas Medical Branch, Galveston, TX 77555, USA
| | - Steven J Ludtke
- Verna and Marrs Mclean Department of Biochemistry and Molecular Biology, Baylor College of Medicine, Houston, TX 77030, USA
| | - B Montgomery Pettitt
- Department of Pharmacology and Toxicology, University of Texas Medical Branch, Galveston, TX 77555, USA; Department of Biochemistry and Molecular Biology, University of Texas Medical Branch, Galveston, TX 77555, USA; Sealy Center for Structural Biology and Molecular Biophysics, University of Texas Medical Branch, Galveston, TX 77555, USA
| | - Jonathan A King
- Department of Biology, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - Michael F Schmid
- Division of CryoEM and Bioimaging, SSRL, SLAC National Accelerator Laboratory, Stanford University, Menlo Park, CA 94025, USA
| | - Wah Chiu
- Division of CryoEM and Bioimaging, SSRL, SLAC National Accelerator Laboratory, Stanford University, Menlo Park, CA 94025, USA; Departments of Bioengineering and of Microbiology and Immunoplogy, James H. Clark Center, Stanford University, Stanford, CA 94305, USA.
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36
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Liu Y, He X, Lim W, Mueller J, Lawrie J, Kramer L, Guo J, Niu W. Deciphering molecular details in the assembly of alpha-type carboxysome. Sci Rep 2018; 8:15062. [PMID: 30305640 PMCID: PMC6180065 DOI: 10.1038/s41598-018-33074-x] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2018] [Accepted: 09/12/2018] [Indexed: 01/25/2023] Open
Abstract
Bacterial microcompartments (BMCs) are promising natural protein structures for applications that require the segregation of certain metabolic functions or molecular species in a defined microenvironment. To understand how endogenous cargos are packaged inside the protein shell is key for using BMCs as nano-scale reactors or delivery vesicles. In this report, we studied the encapsulation of RuBisCO into the α-type carboxysome from Halothiobacillus neapolitan. Our experimental data revealed that the CsoS2 scaffold proteins engage RuBisCO enzyme through an interaction with the small subunit (CbbS). In addition, the N domain of the large subunit (CbbL) of RuBisCO interacts with all shell proteins that can form the hexamers. The binding affinity between the N domain of CbbL and one of the major shell proteins, CsoS1C, is within the submicromolar range. The absence of the N domain also prevented the encapsulation of the rest of the RuBisCO subunits. Our findings complete the picture of how RuBisCOs are encapsulated into the α-type carboxysome and provide insights for future studies and engineering of carboxysome as a protein shell.
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Affiliation(s)
- Yilan Liu
- Department of Chemical & Biomolecular Engineering, University of Nebraska-Lincoln, Lincoln, Nebraska, 68588, United States
| | - Xinyuan He
- Department of Chemical & Biomolecular Engineering, University of Nebraska-Lincoln, Lincoln, Nebraska, 68588, United States
| | - Weiping Lim
- Department of Chemical & Biomolecular Engineering, University of Nebraska-Lincoln, Lincoln, Nebraska, 68588, United States
| | - Joshua Mueller
- Department of Chemical & Biomolecular Engineering, University of Nebraska-Lincoln, Lincoln, Nebraska, 68588, United States
| | - Justin Lawrie
- Department of Chemistry, University of Nebraska-Lincoln, Lincoln, Nebraska, 68588, United States
| | - Levi Kramer
- Department of Chemical & Biomolecular Engineering, University of Nebraska-Lincoln, Lincoln, Nebraska, 68588, United States
| | - Jiantao Guo
- Department of Chemistry, University of Nebraska-Lincoln, Lincoln, Nebraska, 68588, United States
| | - Wei Niu
- Department of Chemical & Biomolecular Engineering, University of Nebraska-Lincoln, Lincoln, Nebraska, 68588, United States.
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37
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Biotechnological Advances in Bacterial Microcompartment Technology. Trends Biotechnol 2018; 37:325-336. [PMID: 30236905 DOI: 10.1016/j.tibtech.2018.08.006] [Citation(s) in RCA: 34] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2018] [Revised: 08/22/2018] [Accepted: 08/23/2018] [Indexed: 12/22/2022]
Abstract
Bacterial microcompartments (BMCs) represent proteinaceous macromolecular nanobioreactors that are found in a broad range of bacteria, and which are associated with either anabolic or catabolic processes. They consist of a semipermeable outer shell that packages a central metabolic enzyme or pathway, providing both enhanced flux and protection against toxic intermediates. Recombinant production of BMCs has led to their repurposing with the incorporation of altogether new pathways. Deconstructing BMCs into their component parts has shown that some individual shell proteins self-associate into filaments that can be further modified into a cytoplasmic scaffold, or cytoscaffold, to which enzymes/proteins can be targeted. BMCs therefore represent a modular system that is highly suited for engineering biological systems for useful purposes.
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Long BM, Hee WY, Sharwood RE, Rae BD, Kaines S, Lim YL, Nguyen ND, Massey B, Bala S, von Caemmerer S, Badger MR, Price GD. Carboxysome encapsulation of the CO 2-fixing enzyme Rubisco in tobacco chloroplasts. Nat Commun 2018; 9:3570. [PMID: 30177711 PMCID: PMC6120970 DOI: 10.1038/s41467-018-06044-0] [Citation(s) in RCA: 141] [Impact Index Per Article: 23.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2018] [Accepted: 08/12/2018] [Indexed: 12/30/2022] Open
Abstract
A long-term strategy to enhance global crop photosynthesis and yield involves the introduction of cyanobacterial CO2-concentrating mechanisms (CCMs) into plant chloroplasts. Cyanobacterial CCMs enable relatively rapid CO2 fixation by elevating intracellular inorganic carbon as bicarbonate, then concentrating it as CO2 around the enzyme Rubisco in specialized protein micro-compartments called carboxysomes. To date, chloroplastic expression of carboxysomes has been elusive, requiring coordinated expression of almost a dozen proteins. Here we successfully produce simplified carboxysomes, isometric with those of the source organism Cyanobium, within tobacco chloroplasts. We replace the endogenous Rubisco large subunit gene with cyanobacterial Form-1A Rubisco large and small subunit genes, along with genes for two key α-carboxysome structural proteins. This minimal gene set produces carboxysomes, which encapsulate the introduced Rubisco and enable autotrophic growth at elevated CO2. This result demonstrates the formation of α-carboxysomes from a reduced gene set, informing the step-wise construction of fully functional α-carboxysomes in chloroplasts.
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Affiliation(s)
- Benedict M Long
- Realizing Increased Photosynthetic Efficiency (RIPE), The Australian National University, 134 Linnaeus Way, Acton, ACT, 2601, Australia.
| | - Wei Yih Hee
- Realizing Increased Photosynthetic Efficiency (RIPE), The Australian National University, 134 Linnaeus Way, Acton, ACT, 2601, Australia
| | - Robert E Sharwood
- Australian Research Council Centre of Excellence for Translational Photosynthesis, Research School of Biology, The Australian National University, 134 Linnaeus Way, Acton, ACT, 2601, Australia
| | - 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
| | - Sarah Kaines
- Realizing Increased Photosynthetic Efficiency (RIPE), The Australian National University, 134 Linnaeus Way, Acton, ACT, 2601, Australia
| | - Yi-Leen Lim
- Realizing Increased Photosynthetic Efficiency (RIPE), 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
| | - Baxter Massey
- Realizing Increased Photosynthetic Efficiency (RIPE), The Australian National University, 134 Linnaeus Way, Acton, ACT, 2601, Australia
| | - Soumi Bala
- Australian Research Council Centre of Excellence for Translational Photosynthesis, Research School of Biology, The Australian National University, 134 Linnaeus Way, Acton, ACT, 2601, Australia
| | - Susanne von Caemmerer
- Realizing Increased Photosynthetic Efficiency (RIPE), The Australian National University, 134 Linnaeus Way, Acton, ACT, 2601, Australia
- Australian Research Council Centre of Excellence for Translational Photosynthesis, Research School of Biology, The Australian National University, 134 Linnaeus Way, Acton, ACT, 2601, Australia
| | - Murray R Badger
- Realizing Increased Photosynthetic Efficiency (RIPE), The Australian National University, 134 Linnaeus Way, Acton, ACT, 2601, Australia
- 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
- Realizing Increased Photosynthetic Efficiency (RIPE), The Australian National University, 134 Linnaeus Way, Acton, ACT, 2601, Australia
- Australian Research Council Centre of Excellence for Translational Photosynthesis, Research School of Biology, The Australian National University, 134 Linnaeus Way, Acton, ACT, 2601, Australia
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Dai W, Chen M, Myers C, Ludtke SJ, Pettitt BM, King JA, Schmid MF, Chiu W. Visualizing Individual RuBisCO and Its Assembly into Carboxysomes in Marine Cyanobacteria by Cryo-Electron Tomography. J Mol Biol 2018; 430:4156-4167. [PMID: 30138616 DOI: 10.1016/j.jmb.2018.08.013] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2018] [Revised: 07/29/2018] [Accepted: 08/13/2018] [Indexed: 12/31/2022]
Abstract
Cyanobacteria are photosynthetic organisms responsible for ~25% of the organic carbon fixation on earth. A key step in carbon fixation is catalyzed by ribulose bisphosphate carboxylase/oxygenase (RuBisCO), the most abundant enzyme in the biosphere. Applying Zernike phase-contrast electron cryo-tomography and automated annotation, we identified individual RuBisCO molecules and their assembly intermediates leading to the formation of carboxysomes inside Syn5 cyanophage infected cyanobacteria Synechococcus sp. WH8109 cells. Surprisingly, more RuBisCO molecules were found to be present as cytosolic free-standing complexes or clusters than as packaged assemblies inside carboxysomes. Cytosolic RuBisCO clusters and partially assembled carboxysomes identified in the cell tomograms support a concurrent assembly model involving both the protein shell and the enclosed RuBisCO. In mature carboxysomes, RuBisCO is neither randomly nor strictly icosahedrally packed within protein shells of variable sizes. A time-averaged molecular dynamics simulation showed a semi-liquid probability distribution of the RuBisCO in carboxysomes and correlated well with carboxysome subtomogram averages. Our structural observations reveal the various stages of RuBisCO assemblies, which could be important for understanding cellular function.
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Affiliation(s)
- Wei Dai
- Department of Cell Biology and Neuroscience & Institute for Quantitative Biomedicine, Rutgers University, Piscataway, NJ 08854, USA.
| | - Muyuan Chen
- Verna and Marrs Mclean Department of Biochemistry and Molecular Biology, Baylor College of Medicine, Houston, TX 77030, USA
| | - Christopher Myers
- Department of Pharmacology and Toxicology, University of Texas Medical Branch, Galveston, TX 77555, USA; Department of Biochemistry and Molecular Biology, University of Texas Medical Branch, Galveston, TX 77555, USA; Sealy Center for Structural Biology and Molecular Biophysics, University of Texas Medical Branch, Galveston, TX 77555, USA
| | - Steven J Ludtke
- Verna and Marrs Mclean Department of Biochemistry and Molecular Biology, Baylor College of Medicine, Houston, TX 77030, USA
| | - B Montgomery Pettitt
- Department of Pharmacology and Toxicology, University of Texas Medical Branch, Galveston, TX 77555, USA; Department of Biochemistry and Molecular Biology, University of Texas Medical Branch, Galveston, TX 77555, USA; Sealy Center for Structural Biology and Molecular Biophysics, University of Texas Medical Branch, Galveston, TX 77555, USA
| | - Jonathan A King
- Department of Biology, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - Michael F Schmid
- Division of CryoEM and Bioimaging, SSRL, SLAC National Accelerator Laboratory, Stanford University, Menlo Park, CA 94025, USA
| | - Wah Chiu
- Division of CryoEM and Bioimaging, SSRL, SLAC National Accelerator Laboratory, Stanford University, Menlo Park, CA 94025, USA; Departments of Bioengineering and of Microbiology and Immunoplogy, James H. Clark Center, Stanford University, Stanford, CA 94305, USA.
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40
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Mohajerani F, Hagan MF. The role of the encapsulated cargo in microcompartment assembly. PLoS Comput Biol 2018; 14:e1006351. [PMID: 30063715 PMCID: PMC6086489 DOI: 10.1371/journal.pcbi.1006351] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2018] [Revised: 08/10/2018] [Accepted: 07/10/2018] [Indexed: 11/19/2022] Open
Abstract
Bacterial microcompartments are large, roughly icosahedral shells that assemble around enzymes and reactants involved in certain metabolic pathways in bacteria. Motivated by microcompartment assembly, we use coarse-grained computational and theoretical modeling to study the factors that control the size and morphology of a protein shell assembling around hundreds to thousands of molecules. We perform dynamical simulations of shell assembly in the presence and absence of cargo over a range of interaction strengths, subunit and cargo stoichiometries, and the shell spontaneous curvature. Depending on these parameters, we find that the presence of a cargo can either increase or decrease the size of a shell relative to its intrinsic spontaneous curvature, as seen in recent experiments. These features are controlled by a balance of kinetic and thermodynamic effects, and the shell size is assembly pathway dependent. We discuss implications of these results for synthetic biology efforts to target new enzymes to microcompartment interiors.
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Affiliation(s)
- Farzaneh Mohajerani
- Martin A. Fisher School of Physics, Brandeis University, Waltham, Massachusetts, United States of America
| | - Michael F. Hagan
- Martin A. Fisher School of Physics, Brandeis University, Waltham, Massachusetts, United States of America
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41
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Abstract
Bacterial microcompartments (BMCs) are self-assembling organelles that consist of an enzymatic core that is encapsulated by a selectively permeable protein shell. The potential to form BMCs is widespread and found across the kingdom Bacteria. BMCs have crucial roles in carbon dioxide fixation in autotrophs and the catabolism of organic substrates in heterotrophs. They contribute to the metabolic versatility of bacteria, providing a competitive advantage in specific environmental niches. Although BMCs were first visualized more than 60 years ago, it is mainly in the past decade that progress has been made in understanding their metabolic diversity and the structural basis of their assembly and function. This progress has not only heightened our understanding of their role in microbial metabolism but is also beginning to enable their use in a variety of applications in synthetic biology. In this Review, we focus on recent insights into the structure, assembly, diversity and function of BMCs.
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Affiliation(s)
- Cheryl A. Kerfeld
- MSU-DOE Plant Research Laboratory, Michigan State University, East Lansing, MI 48824, USA
- Molecular Biophysics and Integrated Bioimaging Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA
- Department of Biochemistry and Molecular Biology, Michigan State University, East Lansing, MI 48824, USA
| | - Clement Aussignargues
- 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
| | - Jan Zarzycki
- Max-Planck-Institute for Terrestrial Microbiology, D-35043, Marburg, Germany
| | - Fei Cai
- Molecular Biophysics and Integrated Bioimaging Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA
| | - Markus Sutter
- MSU-DOE Plant Research Laboratory, Michigan State University, East Lansing, MI 48824, USA
- Molecular Biophysics and Integrated Bioimaging Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA
- Department of Biochemistry and Molecular Biology, Michigan State University, East Lansing, MI 48824, USA
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42
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Chaijarasphong T, Savage DF. Sequestered: Design and Construction of Synthetic Organelles. Synth Biol (Oxf) 2018. [DOI: 10.1002/9783527688104.ch14] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Affiliation(s)
- Thawatchai Chaijarasphong
- Mahidol University; Faculty of Science, Department of Biotechnology; Rama VI Rd. Bangkok 10400 Thailand
| | - David F. Savage
- University of California; Department of Molecular and Cell Biology; 2151 Berkeley Way, Berkeley CA 94720 USA
- University of California; Department of Chemistry; 2151 Berkeley Way, Berkeley CA 94720 USA
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43
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Freeman Rosenzweig ES, Xu B, Kuhn Cuellar L, Martinez-Sanchez A, Schaffer M, Strauss M, Cartwright HN, Ronceray P, Plitzko JM, Förster F, Wingreen NS, Engel BD, Mackinder LCM, Jonikas MC. The Eukaryotic CO 2-Concentrating Organelle Is Liquid-like and Exhibits Dynamic Reorganization. Cell 2017; 171:148-162.e19. [PMID: 28938114 PMCID: PMC5671343 DOI: 10.1016/j.cell.2017.08.008] [Citation(s) in RCA: 217] [Impact Index Per Article: 31.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2017] [Revised: 06/12/2017] [Accepted: 08/04/2017] [Indexed: 12/31/2022]
Abstract
Approximately 30%-40% of global CO2 fixation occurs inside a non-membrane-bound organelle called the pyrenoid, which is found within the chloroplasts of most eukaryotic algae. The pyrenoid matrix is densely packed with the CO2-fixing enzyme Rubisco and is thought to be a crystalline or amorphous solid. Here, we show that the pyrenoid matrix of the unicellular alga Chlamydomonas reinhardtii is not crystalline but behaves as a liquid that dissolves and condenses during cell division. Furthermore, we show that new pyrenoids are formed both by fission and de novo assembly. Our modeling predicts the existence of a "magic number" effect associated with special, highly stable heterocomplexes that influences phase separation in liquid-like organelles. This view of the pyrenoid matrix as a phase-separated compartment provides a paradigm for understanding its structure, biogenesis, and regulation. More broadly, our findings expand our understanding of the principles that govern the architecture and inheritance of liquid-like organelles.
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Affiliation(s)
- Elizabeth S Freeman Rosenzweig
- Department of Biology, Stanford University, Stanford, CA 94305, USA; Department of Plant Biology, Carnegie Institution for Science, Stanford, CA 94305, USA
| | - Bin Xu
- Department of Physics, Princeton University, Princeton, NJ 08544, USA
| | - Luis Kuhn Cuellar
- Department of Molecular Structural Biology, Max Planck Institute of Biochemistry, 82152 Martinsried, Germany
| | - Antonio Martinez-Sanchez
- Department of Molecular Structural Biology, Max Planck Institute of Biochemistry, 82152 Martinsried, Germany
| | - Miroslava Schaffer
- Department of Molecular Structural Biology, Max Planck Institute of Biochemistry, 82152 Martinsried, Germany
| | - Mike Strauss
- Cryo-EM Facility, Max Planck Institute of Biochemistry, 82152 Martinsried, Germany
| | - Heather N Cartwright
- Department of Plant Biology, Carnegie Institution for Science, Stanford, CA 94305, USA
| | - Pierre Ronceray
- Princeton Center for Theoretical Science, Princeton University, Princeton, NJ 08544, USA
| | - Jürgen M Plitzko
- Department of Molecular Structural Biology, Max Planck Institute of Biochemistry, 82152 Martinsried, Germany
| | - Friedrich Förster
- Department of Molecular Structural Biology, Max Planck Institute of Biochemistry, 82152 Martinsried, Germany
| | - Ned S Wingreen
- Lewis-Sigler Institute for Integrative Genomics, Princeton University, Princeton, NJ 08544, USA; Department of Molecular Biology, Princeton University, Princeton, NJ 08544, USA.
| | - Benjamin D Engel
- Department of Molecular Structural Biology, Max Planck Institute of Biochemistry, 82152 Martinsried, Germany.
| | - Luke C M Mackinder
- Department of Plant Biology, Carnegie Institution for Science, Stanford, CA 94305, USA
| | - Martin C Jonikas
- Department of Biology, Stanford University, Stanford, CA 94305, USA; Department of Plant Biology, Carnegie Institution for Science, Stanford, CA 94305, USA; Department of Molecular Biology, Princeton University, Princeton, NJ 08544, USA.
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44
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Turmo A, Gonzalez-Esquer CR, Kerfeld CA. Carboxysomes: metabolic modules for CO2 fixation. FEMS Microbiol Lett 2017; 364:4082729. [DOI: 10.1093/femsle/fnx176] [Citation(s) in RCA: 59] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2017] [Accepted: 08/12/2017] [Indexed: 11/13/2022] Open
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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. JOURNAL OF EXPERIMENTAL BOTANY 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] [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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46
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Sommer M, Cai F, Melnicki M, Kerfeld CA. β-Carboxysome bioinformatics: identification and evolution of new bacterial microcompartment protein gene classes and core locus constraints. JOURNAL OF EXPERIMENTAL BOTANY 2017; 68:3841-3855. [PMID: 28419380 PMCID: PMC5853843 DOI: 10.1093/jxb/erx115] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/21/2016] [Accepted: 03/18/2017] [Indexed: 05/03/2023]
Abstract
Carboxysomes are bacterial microcompartments (BMCs) that enhance CO2 fixation in all cyanobacteria. Structurally, carboxysome shell proteins are classified according to the type of oligomer formed: hexameric (BMC-H), trimeric (BMC-T) and pentameric (BMC-P) proteins. To understand the forces driving the evolution of the carboxysome shell, we conducted a bioinformatic study of genes encoding β-carboxysome shell proteins, taking advantage of the recent large increase in sequenced cyanobacterial genomes. In addition to the four well-established BMC-H (CcmK1-4) classes, our analysis reveals two new CcmK classes, which we name CcmK5 and CcmK6. CcmK5 is phylogenetically closest to CcmK3 and CcmK4, and the ccmK5 gene is found only in genomes lacking ccmK3 and ccmk4 genes. ccmK6 is found predominantly in heterocyst-forming cyanobacteria. The gene encoding the BMC-T homolog CcmO is associated with the main carboxysome locus (MCL) in only 60% of all species. We find five evolutionary origins of separation of ccmO from the MCL. Transcriptome analysis demonstrates that satellite ccmO genes, in contrast to MCL-associated ccmO genes, are never co-regulated with other MCL genes. The dispersal of carboxysome shell genes across the genome allows for distinct regulation of their expression, perhaps in response to changes in environmental conditions.
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Affiliation(s)
- Manuel Sommer
- Department of Plant and Microbial Biology, UC Berkeley, Berkeley, CA, USA
- MBIB Division, Lawrence Berkeley National Laboratory, Berkeley, CA, USA
| | - Fei Cai
- Department of Plant and Microbial Biology, UC Berkeley, Berkeley, CA, USA
- MBIB Division, Lawrence Berkeley National Laboratory, Berkeley, CA, USA
| | - Matthew Melnicki
- MSU-DOE Plant Research Laboratory and Department of Biochemistry and Molecular Biology, Michigan State University, East Lansing, MI, USA
- MBIB Division, Lawrence Berkeley National Laboratory, Berkeley, CA, USA
| | - Cheryl A Kerfeld
- Department of Plant and Microbial Biology, UC Berkeley, Berkeley, CA, USA
- MSU-DOE Plant Research Laboratory and Department of Biochemistry and Molecular Biology, Michigan State University, East Lansing, MI, USA
- MBIB Division, Lawrence Berkeley National Laboratory, Berkeley, CA, USA
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47
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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. JOURNAL OF EXPERIMENTAL BOTANY 2017; 68:3717-3737. [PMID: 28444330 DOI: 10.1093/jxb/erx133] [Citation(s) in RCA: 72] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [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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48
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Hinzpeter F, Gerland U, Tostevin F. Optimal Compartmentalization Strategies for Metabolic Microcompartments. Biophys J 2017; 112:767-779. [PMID: 28256236 PMCID: PMC5340097 DOI: 10.1016/j.bpj.2016.11.3194] [Citation(s) in RCA: 55] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2016] [Revised: 11/18/2016] [Accepted: 11/28/2016] [Indexed: 11/16/2022] Open
Abstract
Intracellular compartmentalization of cooperating enzymes is a strategy that is frequently used by cells. Segregation of enzymes that catalyze sequential reactions can alleviate challenges such as toxic pathway intermediates, competing metabolic reactions, and slow reaction rates. Inspired by nature, synthetic biologists also seek to encapsulate engineered metabolic pathways within vesicles or proteinaceous shells to enhance the yield of industrially and pharmaceutically useful products. Although enzymatic compartments have been extensively studied experimentally, a quantitative understanding of the underlying design principles is still lacking. Here, we study theoretically how the size and enzymatic composition of compartments should be chosen so as to maximize the productivity of a model metabolic pathway. We find that maximizing productivity requires compartments larger than a certain critical size. The enzyme density within each compartment should be tuned according to a power-law scaling in the compartment size. We explain these observations using an analytically solvable, well-mixed approximation. We also investigate the qualitatively different compartmentalization strategies that emerge in parameter regimes where this approximation breaks down. Our results suggest that the different sizes and enzyme packings of α- and β-carboxysomes each constitute an optimal compartmentalization strategy given the properties of their respective protein shells.
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Affiliation(s)
- Florian Hinzpeter
- Department of Physics, Technische Universität München, Garching, Germany.
| | - Ulrich Gerland
- Department of Physics, Technische Universität München, Garching, Germany
| | - Filipe Tostevin
- Department of Physics, Technische Universität München, Garching, Germany
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49
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Atkins JF, Loughran G, Bhatt PR, Firth AE, Baranov PV. Ribosomal frameshifting and transcriptional slippage: From genetic steganography and cryptography to adventitious use. Nucleic Acids Res 2016; 44:7007-78. [PMID: 27436286 PMCID: PMC5009743 DOI: 10.1093/nar/gkw530] [Citation(s) in RCA: 161] [Impact Index Per Article: 20.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2016] [Accepted: 05/26/2016] [Indexed: 12/15/2022] Open
Abstract
Genetic decoding is not ‘frozen’ as was earlier thought, but dynamic. One facet of this is frameshifting that often results in synthesis of a C-terminal region encoded by a new frame. Ribosomal frameshifting is utilized for the synthesis of additional products, for regulatory purposes and for translational ‘correction’ of problem or ‘savior’ indels. Utilization for synthesis of additional products occurs prominently in the decoding of mobile chromosomal element and viral genomes. One class of regulatory frameshifting of stable chromosomal genes governs cellular polyamine levels from yeasts to humans. In many cases of productively utilized frameshifting, the proportion of ribosomes that frameshift at a shift-prone site is enhanced by specific nascent peptide or mRNA context features. Such mRNA signals, which can be 5′ or 3′ of the shift site or both, can act by pairing with ribosomal RNA or as stem loops or pseudoknots even with one component being 4 kb 3′ from the shift site. Transcriptional realignment at slippage-prone sequences also generates productively utilized products encoded trans-frame with respect to the genomic sequence. This too can be enhanced by nucleic acid structure. Together with dynamic codon redefinition, frameshifting is one of the forms of recoding that enriches gene expression.
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Affiliation(s)
- John F Atkins
- School of Biochemistry and Cell Biology, University College Cork, Cork, Ireland School of Microbiology, University College Cork, Cork, Ireland Department of Human Genetics, University of Utah, Salt Lake City, UT 84112, USA
| | - Gary Loughran
- School of Biochemistry and Cell Biology, University College Cork, Cork, Ireland
| | - Pramod R Bhatt
- School of Biochemistry and Cell Biology, University College Cork, Cork, Ireland
| | - Andrew E Firth
- Division of Virology, Department of Pathology, University of Cambridge, Hills Road, Cambridge CB2 0QQ, UK
| | - Pavel V Baranov
- School of Biochemistry and Cell Biology, University College Cork, Cork, Ireland
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Gonzalez-Esquer CR, Newnham SE, Kerfeld CA. Bacterial microcompartments as metabolic modules for plant synthetic biology. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2016; 87:66-75. [PMID: 26991644 DOI: 10.1111/tpj.13166] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/21/2016] [Revised: 03/04/2016] [Accepted: 03/08/2016] [Indexed: 05/28/2023]
Abstract
Bacterial microcompartments (BMCs) are megadalton-sized protein assemblies that enclose segments of metabolic pathways within cells. They increase the catalytic efficiency of the encapsulated enzymes while sequestering volatile or toxic intermediates from the bulk cytosol. The first BMCs discovered were the carboxysomes of cyanobacteria. Carboxysomes compartmentalize the enzyme ribulose-1,5-bisphosphate carboxylase/oxygenase (RuBisCO) with carbonic anhydrase. They enhance the carboxylase activity of RuBisCO by increasing the local concentration of CO2 in the vicinity of the enzyme's active site. As a metabolic module for carbon fixation, carboxysomes could be transferred to eukaryotic organisms (e.g. plants) to increase photosynthetic efficiency. Within the scope of synthetic biology, carboxysomes and other BMCs hold even greater potential when considered a source of building blocks for the development of nanoreactors or three-dimensional scaffolds to increase the efficiency of either native or heterologously expressed enzymes. The carboxysome serves as an ideal model system for testing approaches to engineering BMCs because their expression in cyanobacteria provides a sensitive screen for form (appearance of polyhedral bodies) and function (ability to grow on air). We recount recent progress in the re-engineering of the carboxysome shell and core to offer a conceptual framework for the development of BMC-based architectures for applications in plant synthetic biology.
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Affiliation(s)
| | - Sarah E Newnham
- MSU-DOE Plant Research Laboratory, Michigan State University, East Lansing, MI, USA
| | - Cheryl A Kerfeld
- MSU-DOE Plant Research Laboratory, Michigan State University, East Lansing, MI, USA
- Physical Biosciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA, USA
- Department of Biochemistry and Molecular Biology, Michigan State University, East Lansing, MI, USA
- Berkeley Synthetic Biology Institute, UC Berkeley, Berkeley, CA, USA
- Department of Plant and Microbial Biology, UC Berkeley, Berkeley, CA, USA
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