1
|
Perdomo JA, Scales JC, Lee W, Kanyuka K, Carmo‐Silva E. Down-regulation of wheat Rubisco activase isoforms expression by virus-induced gene silencing. PLANT DIRECT 2024; 8:e583. [PMID: 38628621 PMCID: PMC11018489 DOI: 10.1002/pld3.583] [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: 06/07/2023] [Revised: 03/17/2024] [Accepted: 03/21/2024] [Indexed: 04/19/2024]
Abstract
Rubisco activase (Rca) is an essential photosynthetic enzyme that removes inhibitors from the catalytic sites of the carboxylating enzyme Rubisco. In wheat, Rca is composed of one longer 46 kDa α-isoform and two shorter 42 kDa β-isoforms encoded by the genes TaRca1 and TaRca2. TaRca1 produces a single transcript from which a short 1β-isoform is expressed, whereas two alternative transcripts are generated from TaRca2 directing expression of either a long 2α-isoform or a short 2β-isoform. The 2β isoform is similar but not identical to 1β. Here, virus-induced gene silencing (VIGS) was used to silence the different TaRca transcripts. Abundance of the transcripts and the respective protein isoforms was then evaluated in the VIGS-treated and control plants. Remarkably, treatment with the construct specifically targeting TaRca1 efficiently decreased expression not only of TaRca1 but also of the two alternative TaRca2 transcripts. Similarly, specific targeting of the TaRca2 transcript encoding a long isoform TaRca2α resulted in silencing of both TaRca2 alternative transcripts. The corresponding protein isoforms decreased in abundance. These findings indicate concomitant down-regulation of TaRca1 and TaRca2 at both transcript and protein levels and may impact the feasibility of altering the relative abundance of Rca isoforms in wheat.
Collapse
Affiliation(s)
- Juan Alejandro Perdomo
- Lancaster Environment CentreLancaster UniversityLancasterUK
- School of Pharmacy and Biomedical SciencesUniversity of Central LancashirePrestonUK
| | | | - Wing‐Sham Lee
- Biointeractions and Crop ProtectionRothamsted ResearchHarpendenUK
| | - Kostya Kanyuka
- Biointeractions and Crop ProtectionRothamsted ResearchHarpendenUK
- NIABCambridgeUK
| | - Elizabete Carmo‐Silva
- Lancaster Environment CentreLancaster UniversityLancasterUK
- Plant Biology and Crop SciencesRothamsted ResearchHarpendenUK
| |
Collapse
|
2
|
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.
Collapse
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
| |
Collapse
|
3
|
Bi YH, Feng B, Xie WY, Ouyang LL, Ye RX, Zhou ZG. Nuclear-encoded CbbX located in chloroplast is essential for the activity of red-type Rubisco in Saccharina japonica. PLANT PHYSIOLOGY AND BIOCHEMISTRY : PPB 2023; 196:236-245. [PMID: 36731285 DOI: 10.1016/j.plaphy.2023.01.052] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/30/2022] [Revised: 01/25/2023] [Accepted: 01/26/2023] [Indexed: 06/18/2023]
Abstract
Saccharina japonica (Laminariales, Phaeophyta) is a brown alga and the major component of algae beds on the northwest coast of the Pacific Ocean. Rubisco, the key enzyme of CO2 fixation in photosynthesis, is inhibited by nonproductive binding of its substrate RuBP and other sugar phosphates. The inhibited Rubisco in eukaryotic phytoplankton of the red plastid lineage was reactivated by CbbXs, the red-type Rubisco activases, through the process of ATP-hydrolysis-powered remodeling. As well documented, CbbXs had two types of subunits encoded by the plastid or nuclear genome respectively. In this study, both proteins of S. japonica (SjCbbX-n and SjCbbX-p) were localized in the chloroplast illustrated by immuno-electron microscopy technique. GST pull-down detection verified SjCbbX-n could interact with SjCbbX-p. Two-dimensional electrophoresis-based Western blot analysis illustrated that the endogenous SjCbbXs could form heterohexamer in the ratio of 1:1. Activase activity assays showed that although both the recombinant proteins of SjCbbXs were functional, SjCbbX-n illustrated the significantly higher activase activity than SjCbbX-p. Notably, when the two proteins were mixed, the highest specific efficiencies of Rubisco were obtained. These results implied SjCbbX-n may be essential for Rubisco activation. Molecular evolutionary analysis of cbbx genes revealed that cbbx-n originated from the duplication of cbbx-p and then evolved independently under the positive selection pressure. This is the first report about the functional relationship between the two types of CbbXs in macroalge with the red-type Rubisco and provides useful information for revealing the mechanism of high photosynthetic efficiency of this important kelp.
Collapse
Affiliation(s)
- Yan-Hui Bi
- Key Laboratory of Exploration and Utilization of Aquatic Genetic Resources Conferred By Ministry of Education, Shanghai Ocean University, No. 999 Huchenghuan Road, Nanhui New City, Shanghai, 201306, China
| | - Bing Feng
- Key Laboratory of Exploration and Utilization of Aquatic Genetic Resources Conferred By Ministry of Education, Shanghai Ocean University, No. 999 Huchenghuan Road, Nanhui New City, Shanghai, 201306, China
| | - Wei-Yi Xie
- Key Laboratory of Exploration and Utilization of Aquatic Genetic Resources Conferred By Ministry of Education, Shanghai Ocean University, No. 999 Huchenghuan Road, Nanhui New City, Shanghai, 201306, China
| | - Long-Ling Ouyang
- Chinese Academy of Fishery Science East China Sea Fisheries Research Institute, No. 300 Jungong Road, Shanghai, 200090, China
| | - Rong-Xue Ye
- Key Laboratory of Exploration and Utilization of Aquatic Genetic Resources Conferred By Ministry of Education, Shanghai Ocean University, No. 999 Huchenghuan Road, Nanhui New City, Shanghai, 201306, China
| | - Zhi-Gang Zhou
- International Research Center for Marine Biosciences Conferred By Ministry of Science and Technology, Shanghai Ocean University, No. 999 Huchenghuan Road, Nanhui New City, Shanghai, 201306, China.
| |
Collapse
|
4
|
Mattoon EM, McHargue W, Bailey CE, Zhang N, Chen C, Eckhardt J, Daum CG, Zane M, Pennacchio C, Schmutz J, O'Malley RC, Cheng J, Zhang R. High-throughput identification of novel heat tolerance genes via genome-wide pooled mutant screens in the model green alga Chlamydomonas reinhardtii. PLANT, CELL & ENVIRONMENT 2023; 46:865-888. [PMID: 36479703 PMCID: PMC9898210 DOI: 10.1111/pce.14507] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/13/2022] [Revised: 11/04/2022] [Accepted: 12/05/2022] [Indexed: 06/17/2023]
Abstract
Different high temperatures adversely affect crop and algal yields with various responses in photosynthetic cells. The list of genes required for thermotolerance remains elusive. Additionally, it is unclear how carbon source availability affects heat responses in plants and algae. We utilized the insertional, indexed, genome-saturating mutant library of the unicellular, eukaryotic green alga Chlamydomonas reinhardtii to perform genome-wide, quantitative, pooled screens under moderate (35°C) or acute (40°C) high temperatures with or without organic carbon sources. We identified heat-sensitive mutants based on quantitative growth rates and identified putative heat tolerance genes (HTGs). By triangulating HTGs with heat-induced transcripts or proteins in wildtype cultures and MapMan functional annotations, we presented a high/medium-confidence list of 933 Chlamydomonas genes with putative roles in heat tolerance. Triangulated HTGs include those with known thermotolerance roles and novel genes with little or no functional annotation. About 50% of these high-confidence HTGs in Chlamydomonas have orthologs in green lineage organisms, including crop species. Arabidopsis thaliana mutants deficient in the ortholog of a high-confidence Chlamydomonas HTG were also heat sensitive. This work expands our knowledge of heat responses in photosynthetic cells and provides engineering targets to improve thermotolerance in algae and crops.
Collapse
Affiliation(s)
- Erin M. Mattoon
- Donald Danforth Plant Science Center, St. Louis, Missouri 63132, USA
- Plant and Microbial Biosciences Program, Division of Biology and Biomedical Sciences, Washington University in Saint Louis, St. Louis, Missouri 63130, USA
| | - William McHargue
- Donald Danforth Plant Science Center, St. Louis, Missouri 63132, USA
| | | | - Ningning Zhang
- Donald Danforth Plant Science Center, St. Louis, Missouri 63132, USA
| | - Chen Chen
- Department of Electrical Engineering and Computer Science, University of Missouri, Columbia, Missouri 65211, USA
| | - James Eckhardt
- Donald Danforth Plant Science Center, St. Louis, Missouri 63132, USA
| | - Chris G. Daum
- U.S. Department of Energy, Joint Genome Institute, Lawrence Berkeley National Laboratory, Berkeley, CA, USA
| | - Matt Zane
- U.S. Department of Energy, Joint Genome Institute, Lawrence Berkeley National Laboratory, Berkeley, CA, USA
| | - Christa Pennacchio
- U.S. Department of Energy, Joint Genome Institute, Lawrence Berkeley National Laboratory, Berkeley, CA, USA
| | - Jeremy Schmutz
- U.S. Department of Energy, Joint Genome Institute, Lawrence Berkeley National Laboratory, Berkeley, CA, USA
| | - Ronan C. O'Malley
- U.S. Department of Energy, Joint Genome Institute, Lawrence Berkeley National Laboratory, Berkeley, CA, USA
- Environmental Genomics and Systems Biology, Lawrence Berkeley National Laboratory, Berkeley, CA, USA
| | - Jianlin Cheng
- Department of Electrical Engineering and Computer Science, University of Missouri, Columbia, Missouri 65211, USA
| | - Ru Zhang
- Donald Danforth Plant Science Center, St. Louis, Missouri 63132, USA
| |
Collapse
|
5
|
Waheeda K, Kitchel H, Wang Q, Chiu PL. Molecular mechanism of Rubisco activase: Dynamic assembly and Rubisco remodeling. Front Mol Biosci 2023; 10:1125922. [PMID: 36845545 PMCID: PMC9951593 DOI: 10.3389/fmolb.2023.1125922] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2022] [Accepted: 01/31/2023] [Indexed: 02/12/2023] Open
Abstract
Ribulose-1,5-bisphosphate (RuBP) carboxylase-oxygenase (Rubisco) enzyme is the limiting step of photosynthetic carbon fixation, and its activation is regulated by its co-evolved chaperone, Rubisco activase (Rca). Rca removes the intrinsic sugar phosphate inhibitors occupying the Rubisco active site, allowing RuBP to split into two 3-phosphoglycerate (3PGA) molecules. This review summarizes the evolution, structure, and function of Rca and describes the recent findings regarding the mechanistic model of Rubisco activation by Rca. New knowledge in these areas can significantly enhance crop engineering techniques used to improve crop productivity.
Collapse
Affiliation(s)
- Kazi Waheeda
- School of Molecular Sciences, Arizona State University, Tempe, AZ, United States,Biodesign Center for Applied Structural Discovery, Arizona State University, Tempe, AZ, United States
| | - Heidi Kitchel
- School of Molecular Sciences, Arizona State University, Tempe, AZ, United States,Biodesign Center for Applied Structural Discovery, Arizona State University, Tempe, AZ, United States
| | - Quan Wang
- Laboratory of Chemical Physics, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD, United States
| | - Po-Lin Chiu
- School of Molecular Sciences, Arizona State University, Tempe, AZ, United States,Biodesign Center for Applied Structural Discovery, Arizona State University, Tempe, AZ, United States,*Correspondence: Po-Lin Chiu,
| |
Collapse
|
6
|
Qu Y, Mueller-Cajar O, Yamori W. Improving plant heat tolerance through modification of Rubisco activase in C3 plants to secure crop yield and food security in a future warming world. JOURNAL OF EXPERIMENTAL BOTANY 2023; 74:591-599. [PMID: 35981868 DOI: 10.1093/jxb/erac340] [Citation(s) in RCA: 11] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/28/2022] [Accepted: 08/17/2022] [Indexed: 06/15/2023]
Abstract
The world's population may reach 10 billion by 2050, but 10% still suffer from food shortages. At the same time, global warming threatens food security by decreasing crop yields, so it is necessary to develop crops with enhanced resistance to high temperatures in order to secure the food supply. In this review, the role of Rubisco activase as an important factor in plant heat tolerance is summarized, based on the conclusions of recent findings. Rubisco activase is a molecular chaperone determining the activation of Rubisco, whose heat sensitivity causes reductions of photosynthesis at high temperatures. Thus, the thermostability of Rubisco activase is considered to be critical for improving plant heat tolerance. It has been shown that the introduction of thermostable Rubisco activase through gene editing into Arabidopsis thaliana and from heat-adapted wild Oryza species or C4Zea mays into Oryza sativa improves Rubisco activation, photosynthesis, and plant growth at high temperatures. We propose that developing a universal thermostable Rubisco activase could be a promising direction for further studies.
Collapse
Affiliation(s)
- Yuchen Qu
- Graduate School of Agricultural and Life Sciences, Institute for Sustainable Agri-ecosystem Services, The University of Tokyo, Tokyo, Japan
| | | | - Wataru Yamori
- Graduate School of Agricultural and Life Sciences, Institute for Sustainable Agri-ecosystem Services, The University of Tokyo, Tokyo, Japan
| |
Collapse
|
7
|
Orr DJ, Robijns AKJ, Baker CR, Niyogi KK, Carmo-Silva E. Dynamics of Rubisco regulation by sugar phosphate derivatives and their phosphatases. JOURNAL OF EXPERIMENTAL BOTANY 2023; 74:581-590. [PMID: 36173669 PMCID: PMC9833046 DOI: 10.1093/jxb/erac386] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/07/2022] [Accepted: 09/28/2022] [Indexed: 05/31/2023]
Abstract
Regulating the central CO2-fixing enzyme Rubisco is as complex as its ancient reaction mechanism and involves interaction with a series of cofactors and auxiliary proteins that activate catalytic sites and maintain activity. A key component among the regulatory mechanisms is the binding of sugar phosphate derivatives that inhibit activity. Removal of inhibitors via the action of Rubisco activase is required to restore catalytic competency. In addition, specific phosphatases dephosphorylate newly released inhibitors, rendering them incapable of binding to Rubisco catalytic sites. The best studied inhibitor is 2-carboxy-d-arabinitol 1-phosphate (CA1P), a naturally occurring nocturnal inhibitor that accumulates in most species during darkness and low light, progressively binding to Rubisco. As light increases, Rubisco activase removes CA1P from Rubisco, and the specific phosphatase CA1Pase dephosphorylates CA1P to CA, which cannot bind Rubisco. Misfire products of Rubisco's complex reaction chemistry can also act as inhibitors. One example is xylulose-1,5-bisphosphate (XuBP), which is dephosphorylated by XuBPase. Here we revisit key findings related to sugar phosphate derivatives and their specific phosphatases, highlighting outstanding questions and how further consideration of these inhibitors and their role is important for better understanding the regulation of carbon assimilation.
Collapse
Affiliation(s)
| | - Alice K J Robijns
- Present address: Department of Plant Sciences, University of Cambridge, Downing Street, Cambridge CB2 3EA, UK
| | - Christopher R Baker
- Howard Hughes Medical Institute, Department of Plant and Microbial Biology, University of California, Berkeley, CA, USA
| | - Krishna K Niyogi
- Howard Hughes Medical Institute, Department of Plant and Microbial Biology, University of California, Berkeley, CA, USA
- Molecular Biophysics and Integrated Bioimaging Division, Lawrence Berkeley National Laboratory, Berkeley, CA, USA
| | | |
Collapse
|
8
|
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.
Collapse
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
| |
Collapse
|
9
|
Bauwe H. Photorespiration - Rubisco's repair crew. JOURNAL OF PLANT PHYSIOLOGY 2023; 280:153899. [PMID: 36566670 DOI: 10.1016/j.jplph.2022.153899] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/15/2022] [Revised: 12/11/2022] [Accepted: 12/11/2022] [Indexed: 06/17/2023]
Abstract
The photorespiratory repair pathway (photorespiration in short) was set up from ancient metabolic modules about three billion years ago in cyanobacteria, the later ancestors of chloroplasts. These prokaryotes developed the capacity for oxygenic photosynthesis, i.e. the use of water as a source of electrons and protons (with O2 as a by-product) for the sunlight-driven synthesis of ATP and NADPH for CO2 fixation in the Calvin cycle. However, the CO2-binding enzyme, ribulose 1,5-bisphosphate carboxylase (known under the acronym Rubisco), is not absolutely selective for CO2 and can also use O2 in a side reaction. It then produces 2-phosphoglycolate (2PG), the accumulation of which would inhibit and potentially stop the Calvin cycle and subsequently photosynthetic electron transport. Photorespiration removes the 2-PG and in this way prevents oxygenic photosynthesis from poisoning itself. In plants, the core of photorespiration consists of ten enzymes distributed over three different types of organelles, requiring interorganellar transport and interaction with several auxiliary enzymes. It goes together with the release and to some extent loss of freshly fixed CO2. This disadvantageous feature can be suppressed by CO2-concentrating mechanisms, such as those that evolved in C4 plants thirty million years ago, which enhance CO2 fixation and reduce 2PG synthesis. Photorespiration itself provided a pioneer variant of such mechanisms in the predecessors of C4 plants, C3-C4 intermediate plants. This article is a review and update particularly on the enzyme components of plant photorespiration and their catalytic mechanisms, on the interaction of photorespiration with other metabolism and on its impact on the evolution of photosynthesis. This focus was chosen because a better knowledge of the enzymes involved and how they are embedded in overall plant metabolism can facilitate the targeted use of the now highly advanced methods of metabolic network modelling and flux analysis. Understanding photorespiration more than before as a process that enables, rather than reduces, plant photosynthesis, will help develop rational strategies for crop improvement.
Collapse
Affiliation(s)
- Hermann Bauwe
- University of Rostock, Plant Physiology, Albert-Einstein-Straße 3, D-18051, Rostock, Germany.
| |
Collapse
|
10
|
Regulation of Calvin-Benson cycle enzymes under high temperature stress. ABIOTECH 2022; 3:65-77. [PMID: 36311539 PMCID: PMC9590453 DOI: 10.1007/s42994-022-00068-3] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/18/2021] [Accepted: 01/01/2022] [Indexed: 10/19/2022]
Abstract
The Calvin-Benson cycle (CBC) consists of three critical processes, including fixation of CO2 by Rubisco, reduction of 3-phosphoglycerate (3PGA) to triose phosphate (triose-P) with NADPH and ATP generated by the light reactions, and regeneration of ribulose 1,5-bisphosphate (RuBP) from triose-P. The activities of photosynthesis-related proteins, mainly from the CBC, were found more significantly affected and regulated in plants challenged with high temperature stress, including Rubisco, Rubisco activase (RCA) and the enzymes involved in RuBP regeneration, such as sedoheptulose-1,7-bisphosphatase (SBPase). Over the past years, the regulatory mechanism of CBC, especially for redox-regulation, has attracted major interest, because balancing flux at the various enzymatic reactions and maintaining metabolite levels in a range are of critical importance for the optimal operation of CBC under high temperature stress, providing insights into the genetic manipulation of photosynthesis. Here, we summarize recent progress regarding the identification of various layers of regulation point to the key enzymes of CBC for acclimation to environmental temperature changes along with open questions are also discussed.
Collapse
|
11
|
The CbbQO-type rubisco activases encoded in carboxysome gene clusters can activate carboxysomal form IA rubiscos. J Biol Chem 2021; 298:101476. [PMID: 34890642 PMCID: PMC8718961 DOI: 10.1016/j.jbc.2021.101476] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2021] [Revised: 12/02/2021] [Accepted: 12/03/2021] [Indexed: 01/15/2023] Open
Abstract
The CO2-fixing enzyme rubisco is responsible for almost all carbon fixation. This process frequently requires rubisco activase (Rca) machinery, which couples ATP hydrolysis to the removal of inhibitory sugar phosphates, including the rubisco substrate ribulose 1,5-bisphosphate (RuBP). Rubisco is sometimes compartmentalized in carboxysomes, bacterial microcompartments that enable a carbon dioxide concentrating mechanism (CCM). Characterized carboxysomal rubiscos, however, are not prone to inhibition, and often no activase machinery is associated with these enzymes. Here, we characterize two carboxysomal rubiscos of the form IAC clade that are associated with CbbQO-type Rcas. These enzymes release RuBP at a much lower rate than the canonical carboxysomal rubisco from Synechococcus PCC6301. We found that CbbQO-type Rcas encoded in carboxysome gene clusters can remove RuBP and the tight-binding transition state analog carboxy-arabinitol 1,5-bisphosphate from cognate rubiscos. The Acidithiobacillus ferrooxidans genome encodes two form IA rubiscos associated with two sets of cbbQ and cbbO genes. We show that the two CbbQO activase systems display specificity for the rubisco enzyme encoded in the same gene cluster, and this property can be switched by substituting the C-terminal three residues of the large subunit. Our findings indicate that the kinetic and inhibitory properties of proteobacterial form IA rubiscos are diverse and predict that Rcas may be necessary for some α-carboxysomal CCMs. These findings will have implications for efforts aiming to introduce biophysical CCMs into plants and other hosts for improvement of carbon fixation of crops.
Collapse
|
12
|
An Insight of RuBisCO Evolution through a Multilevel Approach. Biomolecules 2021; 11:biom11121761. [PMID: 34944405 PMCID: PMC8698309 DOI: 10.3390/biom11121761] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2021] [Revised: 10/15/2021] [Accepted: 10/23/2021] [Indexed: 12/28/2022] Open
Abstract
RuBisCO is the most abundant enzyme on earth; it regulates the organic carbon cycle in the biosphere. Studying its structural evolution will help to develop new strategies of genetic improvement in order to increase food production and mitigate CO2 emissions. In the present work, we evaluate how the evolution of sequence and structure among isoforms I, II and III of RuBisCO defines their intrinsic flexibility and residue-residue interactions. To do this, we used a multilevel approach based on phylogenetic inferences, multiple sequence alignment, normal mode analysis, and molecular dynamics. Our results show that the three isoforms exhibit greater fluctuation in the loop between αB and βC, and also present a positive correlation with loop 6, an important region for enzymatic activity because it regulates RuBisCO conformational states. Likewise, an increase in the flexibility of the loop structure between αB and βC, as well as Lys330 (form II) and Lys322 (form III) of loop 6, is important to increase photosynthetic efficiency. Thus, the cross-correlation dynamics analysis showed changes in the direction of movement of the secondary structures in the three isoforms. Finally, key amino acid residues related to the flexibility of the RuBisCO structure were indicated, providing important information for its enzymatic engineering.
Collapse
|
13
|
Iñiguez C, Aguiló-Nicolau P, Galmés J. Improving photosynthesis through the enhancement of Rubisco carboxylation capacity. Biochem Soc Trans 2021; 49:2007-2019. [PMID: 34623388 DOI: 10.1042/bst20201056] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2021] [Revised: 09/07/2021] [Accepted: 09/09/2021] [Indexed: 12/14/2022]
Abstract
Rising human population, along with the reduction in arable land and the impacts of global change, sets out the need for continuously improving agricultural resource use efficiency and crop yield (CY). Bioengineering approaches for photosynthesis optimization have largely demonstrated the potential for enhancing CY. This review is focused on the improvement of Rubisco functioning, which catalyzes the rate-limiting step of CO2 fixation required for plant growth, but also catalyzes the ribulose-bisphosphate oxygenation initiating the carbon and energy wasteful photorespiration pathway. Rubisco carboxylation capacity can be enhanced by engineering the Rubisco large and/or small subunit genes to improve its catalytic traits, or by engineering the mechanisms that provide enhanced Rubisco expression, activation and/or elevated [CO2] around the active sites to favor carboxylation over oxygenation. Recent advances have been made in the expression, assembly and activation of foreign (either natural or mutant) faster and/or more CO2-specific Rubisco versions. Some components of CO2 concentrating mechanisms (CCMs) from bacteria, algae and C4 plants has been successfully expressed in tobacco and rice. Still, none of the transformed plant lines expressing foreign Rubisco versions and/or simplified CCM components were able to grow faster than wild type plants under present atmospheric [CO2] and optimum conditions. However, the results obtained up to date suggest that it might be achievable in the near future. In addition, photosynthetic and yield improvements have already been observed when manipulating Rubisco quantity and activation degree in crops. Therefore, engineering Rubisco carboxylation capacity continues being a promising target for the improvement in photosynthesis and yield.
Collapse
Affiliation(s)
- Concepción Iñiguez
- Research Group on Plant Biology Under Mediterranean Conditions, Universitat de les Illes Balears-INAGEA, Palma, Balearic Islands, Spain
- Department of Ecology, Faculty of Sciences, University of Málaga, Málaga, Spain
| | - Pere Aguiló-Nicolau
- Research Group on Plant Biology Under Mediterranean Conditions, Universitat de les Illes Balears-INAGEA, Palma, Balearic Islands, Spain
| | - Jeroni Galmés
- Research Group on Plant Biology Under Mediterranean Conditions, Universitat de les Illes Balears-INAGEA, Palma, Balearic Islands, Spain
| |
Collapse
|
14
|
Anderson CM, Mattoon EM, Zhang N, Becker E, McHargue W, Yang J, Patel D, Dautermann O, McAdam SAM, Tarin T, Pathak S, Avenson TJ, Berry J, Braud M, Niyogi KK, Wilson M, Nusinow DA, Vargas R, Czymmek KJ, Eveland AL, Zhang R. High light and temperature reduce photosynthetic efficiency through different mechanisms in the C 4 model Setaria viridis. Commun Biol 2021; 4:1092. [PMID: 34531541 PMCID: PMC8446033 DOI: 10.1038/s42003-021-02576-2] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2021] [Accepted: 08/03/2021] [Indexed: 11/09/2022] Open
Abstract
C4 plants frequently experience high light and high temperature conditions in the field, which reduce growth and yield. However, the mechanisms underlying these stress responses in C4 plants have been under-explored, especially the coordination between mesophyll (M) and bundle sheath (BS) cells. We investigated how the C4 model plant Setaria viridis responded to a four-hour high light or high temperature treatment at photosynthetic, transcriptomic, and ultrastructural levels. Although we observed a comparable reduction of photosynthetic efficiency in high light or high temperature treated leaves, detailed analysis of multi-level responses revealed important differences in key pathways and M/BS specificity responding to high light and high temperature. We provide a systematic analysis of high light and high temperature responses in S. viridis, reveal different acclimation strategies to these two stresses in C4 plants, discover unique light/temperature responses in C4 plants in comparison to C3 plants, and identify potential targets to improve abiotic stress tolerance in C4 crops.
Collapse
Affiliation(s)
| | - Erin M Mattoon
- Donald Danforth Plant Science Center, St. Louis, MO, USA.,Plant and Microbial Biosciences Program, Division of Biology and Biomedical Sciences, Washington University in Saint Louis, St. Louis, MO, USA
| | - Ningning Zhang
- Donald Danforth Plant Science Center, St. Louis, MO, USA
| | - Eric Becker
- Donald Danforth Plant Science Center, St. Louis, MO, USA
| | | | - Jiani Yang
- Donald Danforth Plant Science Center, St. Louis, MO, USA
| | - Dhruv Patel
- Department of Plant and Microbial Biology, University of California, Berkeley, CA, USA
| | - Oliver Dautermann
- Department of Plant and Microbial Biology, University of California, Berkeley, CA, USA
| | - Scott A M McAdam
- Purdue Center for Plant Biology, Department of Botany and Plant Pathology, Purdue University, West Lafayette, IN, USA
| | - Tonantzin Tarin
- Department of Plant and Soil Sciences, University of Delaware, Newark, DE, USA.,Instituto de Ecología, Universidad Nacional Autónoma de México, Mexico City, Mexico
| | - Sunita Pathak
- Donald Danforth Plant Science Center, St. Louis, MO, USA
| | - Tom J Avenson
- Department of Plant Sciences, University of Cambridge, Cambridge, UK
| | - Jeffrey Berry
- Donald Danforth Plant Science Center, St. Louis, MO, USA
| | - Maxwell Braud
- Donald Danforth Plant Science Center, St. Louis, MO, USA
| | - Krishna K Niyogi
- Department of Plant and Microbial Biology, University of California, Berkeley, CA, USA.,Howard Hughes Medical Institute, Berkeley, CA, USA.,Molecular Biophysics and Integrated Bioimaging Division, Lawrence Berkeley National Laboratory, Berkeley, CA, USA
| | | | | | - Rodrigo Vargas
- Department of Plant and Soil Sciences, University of Delaware, Newark, DE, USA
| | - Kirk J Czymmek
- Donald Danforth Plant Science Center, St. Louis, MO, USA
| | | | - Ru Zhang
- Donald Danforth Plant Science Center, St. Louis, MO, USA.
| |
Collapse
|
15
|
Correia PMP, da Silva AB, Roitsch T, Carmo-Silva E, Marques da Silva J. Photoprotection and optimization of sucrose usage contribute to faster recovery of photosynthesis after water deficit at high temperatures in wheat. PHYSIOLOGIA PLANTARUM 2021; 172:615-628. [PMID: 33010044 DOI: 10.1111/ppl.13227] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/20/2020] [Revised: 09/22/2020] [Accepted: 09/29/2020] [Indexed: 06/11/2023]
Abstract
Plants are increasingly exposed to events of elevated temperature and water deficit, which threaten crop productivity. Understanding the ability to rapidly recover from abiotic stress, restoring carbon assimilation and biomass production, is important to unravel crop climate resilience. This study compared the photosynthetic performance of two Triticum aestivum L. cultivars, Sokoll and Paragon, adapted to the climate of Mexico and UK, respectively, exposed to 1-week water deficit and high temperatures, in isolation or combination. Measurements included photosynthetic assimilation rate, stomatal conductance, in vitro activities of Rubisco (EC 4.1.1.39) and invertase (INV, EC 3.2.1.26), antioxidant capacity and chlorophyll a fluorescence. In both genotypes, under elevated temperatures and water deficit (WD38°C), the photosynthetic limitations were mainly due to stomatal restrictions and to a decrease in the electron transport rate. Chlorophyll a fluorescence parameters clearly indicate differences between the two genotypes in the photoprotection when subjected to WD38°C and showed faster recovery of Paragon after stress relief. The activity of the cytosolic invertase (CytINV) under these stress conditions was strongly related to the fast photosynthesis recovery of Paragon. Taken together, the results suggest that optimal sucrose export/utilization and increased photoprotection of the electron transport machinery are important components to limit yield fluctuations due to water shortage and elevated temperatures.
Collapse
Affiliation(s)
- Pedro M P Correia
- BioISI-Biosystems and Integrative Sciences Institute, Faculdade de Ciências da Universidade de Lisboa, Lisbon, Portugal
- Lancaster Environment Centre, Lancaster University, Lancaster, UK
| | - Anabela B da Silva
- BioISI-Biosystems and Integrative Sciences Institute, Faculdade de Ciências da Universidade de Lisboa, Lisbon, Portugal
| | - Thomas Roitsch
- Department of Plant and Environmental Sciences, Section of Crop Science, Copenhagen University, Copenhagen, Denmark
- Department of Adaptive Biotechnologies, Global Change Research Institute, CAS, Brno, Czech Republic
| | | | - Jorge Marques da Silva
- BioISI-Biosystems and Integrative Sciences Institute, Faculdade de Ciências da Universidade de Lisboa, Lisbon, Portugal
| |
Collapse
|
16
|
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.
Collapse
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
| | | |
Collapse
|
17
|
Pang JJ, Shin JS, Li SY. The Catalytic Role of RuBisCO for in situ CO 2 Recycling in Escherichia coli. Front Bioeng Biotechnol 2020; 8:543807. [PMID: 33330409 PMCID: PMC7734965 DOI: 10.3389/fbioe.2020.543807] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2020] [Accepted: 10/13/2020] [Indexed: 01/22/2023] Open
Abstract
Ribulose-1,5-bisphosphate carboxylase/oxygenase (RuBisCO) is a key enzyme responsible for biological CO2 assimilation. RuBisCO can be heterologously expressed in Escherichia coli so that glucose and CO2 are co-metabolized to achieve high mixotrophic metabolite production, where the theoretical yield of mixotrophic metabolite production is 2.4 mol(ethanol+acetate+pyruvate)/molglucose. However, RuBisCO is known for its low kcat and for forming inhibited complexes with its substrate ribulose-1,5-bisphosphate (RuBP) and other sugar phosphates, yet the inhibited form of RuBisCO can be reversed by RuBisCO activase (Rca). In this study, RuBisCO forms I and II were cloned and expressed in Escherichia coli for in situ CO2 recycling, where CO2 produced during glucose fermentation was recycled and co-metabolized with the glucose. In addition, forms I and II RuBisCO activases were co-expressed with RuBisCO in E. coli to determine their in vivo effects on in situ CO2 recycling. Form I RuBisCO activase (Rca1) was co-expressed with form I RuBisCO and form II RuBisCO activase (Rca2) was co-expressed with form II RuBisCO. The results showed that both form I and form II RuBisCO exhibit comparable activities in E. coli and generated similar levels of in situ CO2 recycling. A significant increase in the total metabolite yield from 1.5 ± 0.1 to 2.2 ± 0.1 mol(ethanol+acetate+pyruvate)/molglucose occurred when Rca2 was co-expressed with form II RuBisCO. Meanwhile, the total metabolite yield increased from 1.7 ± 0.1 to 2.0 ± 0.1 mol(ethanol+acetate+pyruvate)/molglucose when Rca1 was co-expressed with form I RuBisCO. This data suggests that both forms I and II RuBisCO are subject to in vivo RuBP inhibition yet can be relieved by the co-expression of Rca. Interestingly, it is suggested that the in vivo RuBP inhibition of form II RuBisCO can be more easily reversed compared to form I. When the catalytic power of RuBisCO is maintained by Rca, the high activity of phosphoribulokinase (Prk) plays an important role in directing glucose to the RuBisCO-based engineered pathway and fermentation yields of 2.1–2.3 mol(ethanol+acetate+pyruvate)/molglucose can be obtained. This study is the first to demonstrate that in vivo RuBP inhibition of RuBisCO can be a bottleneck for in situ CO2 recycling in E. coli.
Collapse
Affiliation(s)
- Ju-Jiun Pang
- Department of Chemical Engineering, National Chung Hsing University, Taichung City, Taiwan
| | - Jong-Shik Shin
- Department of Biotechnology, Yonsei University, Seoul, South Korea
| | - Si-Yu Li
- Department of Chemical Engineering, National Chung Hsing University, Taichung City, Taiwan.,Innovation and Development Center of Sustainable Agriculture, National Chung Hsing University, Taichung City, Taiwan
| |
Collapse
|
18
|
Wunder T, Mueller-Cajar O. Biomolecular condensates in photosynthesis and metabolism. CURRENT OPINION IN PLANT BIOLOGY 2020; 58:1-7. [PMID: 32966943 DOI: 10.1016/j.pbi.2020.08.006] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/03/2020] [Revised: 07/29/2020] [Accepted: 08/25/2020] [Indexed: 06/11/2023]
Abstract
The transient assembly or sequestration of enzymes into clusters permits the channeling of metabolites, but requires spatiotemporal control. Liquid liquid phase separation (LLPS) has recently emerged as a fundamental concept enabling formation of such assemblies into non-membrane bound organelles. The role of LLPS in the formation of condensates containing the CO2-fixing enzyme Rubisco has recently become appreciated. Both prokaryotic carboxysomes and eukaryotic pyrenoids enhance the carboxylation reaction by enabling the saturation of the enzyme with CO2 gas. Biochemical reconstitution and structural biology are revealing the mechanistic basis of these photosynthetic condensates. At the same time other enzyme clusters, such as purinosomes for de-novo purine biosynthesis and G-bodies containing glycolytic enzymes, are emerging to behave like phase-separated systems. In the near future we anticipate details of many more such metabolic condensates to be revealed, deeply informing our ability to influence metabolic fluxes.
Collapse
Affiliation(s)
- Tobias Wunder
- School of Biological Sciences, Nanyang Technological University, 60 Nanyang Drive, Singapore, 637551, Singapore
| | - Oliver Mueller-Cajar
- School of Biological Sciences, Nanyang Technological University, 60 Nanyang Drive, Singapore, 637551, Singapore.
| |
Collapse
|
19
|
Ng J, Guo Z, Mueller-Cajar O. Rubisco activase requires residues in the large subunit N terminus to remodel inhibited plant Rubisco. J Biol Chem 2020; 295:16427-16435. [PMID: 32948656 PMCID: PMC7705312 DOI: 10.1074/jbc.ra120.015759] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2020] [Revised: 09/09/2020] [Indexed: 11/06/2022] Open
Abstract
The photosynthetic CO2 fixing enzyme ribulose 1,5-bisphosphate carboxylase/oxygenase (Rubisco) forms dead-end inhibited complexes while binding multiple sugar phosphates, including its substrate ribulose 1,5-bisphosphate. Rubisco can be rescued from this inhibited form by molecular chaperones belonging to the ATPases associated with diverse cellular activities (AAA+ proteins) termed Rubisco activases (Rcas). The mechanism of green-type Rca found in higher plants has proved elusive, in part because until recently higher-plant Rubiscos could not be expressed recombinantly. Identifying the interaction sites between Rubisco and Rca is critical to formulate mechanistic hypotheses. Toward that end here we purify and characterize a suite of 33 Arabidopsis Rubisco mutants for their ability to be activated by Rca. Mutation of 17 surface-exposed large subunit residues did not yield variants that were perturbed in their interaction with Rca. In contrast, we find that Rca activity is highly sensitive to truncations and mutations in the conserved N terminus of the Rubisco large subunit. Large subunits lacking residues 1-4 are functional Rubiscos but cannot be activated. Both T5A and T7A substitutions result in functional carboxylases that are poorly activated by Rca, indicating the side chains of these residues form a critical interaction with the chaperone. Many other AAA+ proteins function by threading macromolecules through a central pore of a disc-shaped hexamer. Our results are consistent with a model in which Rca transiently threads the Rubisco large subunit N terminus through the axial pore of the AAA+ hexamer.
Collapse
Affiliation(s)
- Jediael Ng
- School of Biological Sciences, Nanyang Technological University, Singapore
| | - Zhijun Guo
- School of Biological Sciences, Nanyang Technological University, Singapore
| | | |
Collapse
|
20
|
Flamholz AI, Dugan E, Blikstad C, Gleizer S, Ben-Nissan R, Amram S, Antonovsky N, Ravishankar S, Noor E, Bar-Even A, Milo R, Savage DF. Functional reconstitution of a bacterial CO 2 concentrating mechanism in Escherichia coli. eLife 2020; 9:59882. [PMID: 33084575 PMCID: PMC7714395 DOI: 10.7554/elife.59882] [Citation(s) in RCA: 60] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2020] [Accepted: 10/20/2020] [Indexed: 12/19/2022] Open
Abstract
Many photosynthetic organisms employ a CO2 concentrating mechanism (CCM) to increase the rate of CO2 fixation via the Calvin cycle. CCMs catalyze ≈50% of global photosynthesis, yet it remains unclear which genes and proteins are required to produce this complex adaptation. We describe the construction of a functional CCM in a non-native host, achieved by expressing genes from an autotrophic bacterium in an Escherichia coli strain engineered to depend on rubisco carboxylation for growth. Expression of 20 CCM genes enabled E. coli to grow by fixing CO2 from ambient air into biomass, with growth in ambient air depending on the components of the CCM. Bacterial CCMs are therefore genetically compact and readily transplanted, rationalizing their presence in diverse bacteria. Reconstitution enabled genetic experiments refining our understanding of the CCM, thereby laying the groundwork for deeper study and engineering of the cell biology supporting CO2 assimilation in diverse organisms.
Collapse
Affiliation(s)
- Avi I Flamholz
- Department of Molecular and Cell Biology, University of California, BerkeleyBerkeleyUnited States
| | - Eli Dugan
- Department of Molecular and Cell Biology, University of California, BerkeleyBerkeleyUnited States
| | - Cecilia Blikstad
- Department of Molecular and Cell Biology, University of California, BerkeleyBerkeleyUnited States
| | - Shmuel Gleizer
- Department of Plant and Environmental Sciences, Weizmann Institute of ScienceRehovotIsrael
| | - Roee Ben-Nissan
- Department of Plant and Environmental Sciences, Weizmann Institute of ScienceRehovotIsrael
| | - Shira Amram
- Department of Plant and Environmental Sciences, Weizmann Institute of ScienceRehovotIsrael
| | - Niv Antonovsky
- Department of Plant and Environmental Sciences, Weizmann Institute of ScienceRehovotIsrael
| | - Sumedha Ravishankar
- Department of Molecular and Cell Biology, University of California, BerkeleyBerkeleyUnited States
| | - Elad Noor
- Department of Plant and Environmental Sciences, Weizmann Institute of ScienceRehovotIsrael
| | - Arren Bar-Even
- Max Planck Institute of Molecular Plant PhysiologyPotsdamGermany
| | - Ron Milo
- Department of Plant and Environmental Sciences, Weizmann Institute of ScienceRehovotIsrael
| | - David F Savage
- Department of Molecular and Cell Biology, University of California, BerkeleyBerkeleyUnited States
| |
Collapse
|
21
|
Gunn LH, Martin Avila E, Birch R, Whitney SM. The dependency of red Rubisco on its cognate activase for enhancing plant photosynthesis and growth. Proc Natl Acad Sci U S A 2020; 117:25890-25896. [PMID: 32989135 PMCID: PMC7568259 DOI: 10.1073/pnas.2011641117] [Citation(s) in RCA: 31] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
Plant photosynthesis and growth are often limited by the activity of the CO2-fixing enzyme Rubisco. The broad kinetic diversity of Rubisco in nature is accompanied by differences in the composition and compatibility of the ancillary proteins needed for its folding, assembly, and metabolic regulation. Variations in the protein folding needs of catalytically efficient red algae Rubisco prevent their production in plants. Here, we show this impediment does not extend to Rubisco from Rhodobacter sphaeroides (RsRubisco)-a red-type Rubisco able to assemble in plant chloroplasts. In transplastomic tobRsLS lines expressing a codon optimized Rs-rbcLS operon, the messenger RNA (mRNA) abundance was ∼25% of rbcL transcript and RsRubisco ∼40% the Rubisco content in WT tobacco. To mitigate the low activation status of RsRubisco in tobRsLS (∼23% sites active under ambient CO2), the metabolic repair protein RsRca (Rs-activase) was introduced via nuclear transformation. RsRca production in the tobRsLS::X progeny matched endogenous tobacco Rca levels (∼1 µmol protomer·m2) and enhanced RsRubisco activation to 75% under elevated CO2 (1%, vol/vol) growth. Accordingly, the rate of photosynthesis and growth in the tobRsLS::X lines were improved >twofold relative to tobRsLS. Other tobacco lines producing RsRubisco containing alternate diatom and red algae S-subunits were nonviable as CO2-fixation rates (kcatc) were reduced >95% and CO2/O2 specificity impaired 30-50%. We show differences in hybrid and WT RsRubisco biogenesis in tobacco correlated with assembly in Escherichia coli advocating use of this bacterium to preevaluate the kinetic and chloroplast compatibility of engineered RsRubisco, an isoform amenable to directed evolution.
Collapse
Affiliation(s)
- Laura H Gunn
- Plant Science Division, Research School of Biology, The Australian National University, Canberra, ACT 0200, Australia
| | - Elena Martin Avila
- Plant Science Division, Research School of Biology, The Australian National University, Canberra, ACT 0200, Australia
| | - Rosemary Birch
- Plant Science Division, Research School of Biology, The Australian National University, Canberra, ACT 0200, Australia
| | - Spencer M Whitney
- Plant Science Division, Research School of Biology, The Australian National University, Canberra, ACT 0200, Australia
| |
Collapse
|
22
|
Flecken M, Wang H, Popilka L, Hartl FU, Bracher A, Hayer-Hartl M. Dual Functions of a Rubisco Activase in Metabolic Repair and Recruitment to Carboxysomes. Cell 2020; 183:457-473.e20. [PMID: 32979320 DOI: 10.1016/j.cell.2020.09.010] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2020] [Revised: 07/13/2020] [Accepted: 09/01/2020] [Indexed: 01/19/2023]
Abstract
Rubisco, the key enzyme of CO2 fixation in photosynthesis, is prone to inactivation by inhibitory sugar phosphates. Inhibited Rubisco undergoes conformational repair by the hexameric AAA+ chaperone Rubisco activase (Rca) in a process that is not well understood. Here, we performed a structural and mechanistic analysis of cyanobacterial Rca, a close homolog of plant Rca. In the Rca:Rubisco complex, Rca is positioned over the Rubisco catalytic site under repair and pulls the N-terminal tail of the large Rubisco subunit (RbcL) into the hexamer pore. Simultaneous displacement of the C terminus of the adjacent RbcL opens the catalytic site for inhibitor release. An alternative interaction of Rca with Rubisco is mediated by C-terminal domains that resemble the small Rubisco subunit. These domains, together with the N-terminal AAA+ hexamer, ensure that Rca is packaged with Rubisco into carboxysomes. The cyanobacterial Rca is a dual-purpose protein with functions in Rubisco repair and carboxysome organization.
Collapse
Affiliation(s)
- Mirkko Flecken
- Department of Cellular Biochemistry, Max Planck Institute of Biochemistry, Am Klopferspitz 18, 82152 Martinsried, Germany
| | - Huping Wang
- Department of Cellular Biochemistry, Max Planck Institute of Biochemistry, Am Klopferspitz 18, 82152 Martinsried, Germany
| | - Leonhard Popilka
- Department of Cellular Biochemistry, Max Planck Institute of Biochemistry, Am Klopferspitz 18, 82152 Martinsried, Germany
| | - F Ulrich Hartl
- Department of Cellular Biochemistry, Max Planck Institute of Biochemistry, Am Klopferspitz 18, 82152 Martinsried, Germany
| | - Andreas Bracher
- Department of Cellular Biochemistry, Max Planck Institute of Biochemistry, Am Klopferspitz 18, 82152 Martinsried, Germany
| | - Manajit Hayer-Hartl
- Department of Cellular Biochemistry, Max Planck Institute of Biochemistry, Am Klopferspitz 18, 82152 Martinsried, Germany.
| |
Collapse
|
23
|
Chaperone Machineries of Rubisco – The Most Abundant Enzyme. Trends Biochem Sci 2020; 45:748-763. [DOI: 10.1016/j.tibs.2020.05.001] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2020] [Revised: 04/19/2020] [Accepted: 05/04/2020] [Indexed: 12/14/2022]
|
24
|
Crosskey TD, Beckham KS, Wilmanns M. The ATPases of the mycobacterial type VII secretion system: Structural and mechanistic insights into secretion. PROGRESS IN BIOPHYSICS AND MOLECULAR BIOLOGY 2020; 152:25-34. [DOI: 10.1016/j.pbiomolbio.2019.11.008] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/16/2019] [Revised: 11/08/2019] [Accepted: 11/22/2019] [Indexed: 12/12/2022]
|
25
|
Furbank RT, Sharwood R, Estavillo GM, Silva-Perez V, Condon AG. Photons to food: genetic improvement of cereal crop photosynthesis. JOURNAL OF EXPERIMENTAL BOTANY 2020; 71:2226-2238. [PMID: 32083680 PMCID: PMC7135014 DOI: 10.1093/jxb/eraa077] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/23/2019] [Accepted: 02/17/2020] [Indexed: 05/05/2023]
Abstract
Photosynthesis has become a major trait of interest for cereal yield improvement as breeders appear to have reached the theoretical genetic limit for harvest index, the mass of grain as a proportion of crop biomass. Yield improvements afforded by the adoption of green revolution dwarfing genes to wheat and rice are becoming exhausted, and improvements in biomass and radiation use efficiency are now sought in these crops. Exploring genetic diversity in photosynthesis is now possible using high-throughput techniques, and low-cost genotyping facilitates discovery of the genetic architecture underlying this variation. Photosynthetic traits have been shown to be highly heritable, and significant variation is present for these traits in available germplasm. This offers hope that breeding for improved photosynthesis and radiation use efficiency in cereal crops is tractable and a useful shorter term adjunct to genetic and genome engineering to boost yield potential.
Collapse
Affiliation(s)
- Robert T Furbank
- ARC Centre of Excellence for Translational Photosynthesis, Research School of Biology, The Australian National University, Canberra, ACT, Australia
- CSIRO Agriculture and Food, Canberra, ACT, Australia
| | - Robert Sharwood
- ARC Centre of Excellence for Translational Photosynthesis, Research School of Biology, The Australian National University, Canberra, ACT, Australia
| | | | | | | |
Collapse
|
26
|
Lechno-Yossef S, Rohnke BA, Belza ACO, Melnicki MR, Montgomery BL, Kerfeld CA. Cyanobacterial carboxysomes contain an unique rubisco-activase-like protein. THE NEW PHYTOLOGIST 2020; 225:793-806. [PMID: 31518434 DOI: 10.1111/nph.16195] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/25/2019] [Accepted: 09/05/2019] [Indexed: 06/10/2023]
Abstract
In plants, rubisco activase (Rca) regulates rubisco by removing inhibitory molecules such as ribulose-1,5-bisphosphate (RuBP). In cyanobacteria, a homologous protein (activase-like cyanobacterial protein, ALC), contains a distinctive C-terminal fusion resembling the small-subunit of rubisco. Although cyanobacterial rubisco is believed to be less sensitive to RuBP inhibition, the ALC is widely distributed among diverse cyanobacteria. Using microscopy, biochemistry and molecular biology, the cellular localization of the ALC, its effect on carboxysome/cell ultrastructure in Fremyella diplosiphon, and its function in vitro were studied. Bioinformatic analysis uncovered evolutionary relationships between the ALC and rubisco. ALC localizes to carboxysomes and exhibits ATPase activity. Furthermore, the ALC induces rubisco aggregation in a manner similar to that of another carboxysomal protein, M35, and this activity is affected by ATP. An alc deletion mutant showed modified cell morphology when grown under enriched CO2 and impaired regulation of carboxysome biogenesis, without affecting growth rate. Carbamylation of Fremyella recombinant rubisco was inhibited by RuBP, but this inhibition was not relieved by the ALC. The ALC does not appear to function like a canonical Rca; instead, it exerts an effect on the response to CO2 availability at the level of a metabolic module, the carboxysome, through rubisco network formation, and carboxysome organization.
Collapse
Affiliation(s)
- Sigal Lechno-Yossef
- MSU-DOE Plant Research Laboratory, Michigan State University, East Lansing, MI, 48824, USA
- Department of Biochemistry and Molecular Biology, Michigan State University, East Lansing, MI, 48824, USA
| | - Brandon A Rohnke
- MSU-DOE Plant Research Laboratory, Michigan State University, East Lansing, MI, 48824, USA
- Department of Biochemistry and Molecular Biology, Michigan State University, East Lansing, MI, 48824, USA
| | - Ana C O Belza
- MSU-DOE Plant Research Laboratory, Michigan State University, East Lansing, MI, 48824, USA
| | - Matthew R Melnicki
- MSU-DOE Plant Research Laboratory, Michigan State University, East Lansing, MI, 48824, USA
| | - Beronda L Montgomery
- MSU-DOE Plant Research Laboratory, Michigan State University, East Lansing, MI, 48824, USA
- Department of Biochemistry and Molecular Biology, Michigan State University, East Lansing, MI, 48824, USA
- Department of Microbiology and Molecular Genetics, Michigan State University, East Lansing, MI, 48824, USA
| | - Cheryl A Kerfeld
- MSU-DOE Plant Research Laboratory, Michigan State University, East Lansing, MI, 48824, USA
- Department of Biochemistry and Molecular Biology, Michigan State University, East Lansing, MI, 48824, USA
- Environmental Genomics and Systems Biology and Molecular Biophysics and Integrated Bioimaging Divisions, Lawrence Berkeley National Laboratory, Berkeley, CA, 94720, USA
| |
Collapse
|
27
|
Insights into the mechanism and regulation of the CbbQO-type Rubisco activase, a MoxR AAA+ ATPase. Proc Natl Acad Sci U S A 2019; 117:381-387. [PMID: 31848241 DOI: 10.1073/pnas.1911123117] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
The vast majority of biological carbon dioxide fixation relies on the function of ribulose 1,5-bisphosphate carboxylase/oxygenase (Rubisco). In most cases the enzyme exhibits a tendency to become inhibited by its substrate RuBP and other sugar phosphates. The inhibition is counteracted by diverse molecular chaperones known as Rubisco activases (Rcas). In some chemoautotrophic bacteria, the CbbQO-type Rca Q2O2 repairs inhibited active sites of hexameric form II Rubisco. The 2.2-Å crystal structure of the MoxR AAA+ protein CbbQ2 from Acidithiobacillus ferrooxidans reveals the helix 2 insert (H2I) that is critical for Rca function and forms the axial pore of the CbbQ hexamer. Negative-stain electron microscopy shows that the essential CbbO adaptor protein binds to the conserved, concave side of the CbbQ2 hexamer. Site-directed mutagenesis supports a model in which adenosine 5'-triphosphate (ATP)-powered movements of the H2I are transmitted to CbbO via the concave residue L85. The basal ATPase activity of Q2O2 Rca is repressed but strongly stimulated by inhibited Rubisco. The characterization of multiple variants where this repression is released indicates that binding of inhibited Rubisco to the C-terminal CbbO VWA domain initiates a signal toward the CbbQ active site that is propagated via elements that include the CbbQ α4-β4 loop, pore loop 1, and the presensor 1-β hairpin (PS1-βH). Detailed mechanistic insights into the enzyme repair chaperones of the highly diverse CO2 fixation machinery of Proteobacteria will facilitate their successful implementation in synthetic biology ventures.
Collapse
|
28
|
Desmarais JJ, Flamholz AI, Blikstad C, Dugan EJ, Laughlin TG, Oltrogge LM, Chen AW, Wetmore K, Diamond S, Wang JY, Savage DF. DABs are inorganic carbon pumps found throughout prokaryotic phyla. Nat Microbiol 2019; 4:2204-2215. [PMID: 31406332 PMCID: PMC10184468 DOI: 10.1038/s41564-019-0520-8] [Citation(s) in RCA: 31] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2019] [Revised: 06/13/2019] [Accepted: 06/20/2019] [Indexed: 12/30/2022]
Abstract
Bacterial autotrophs often rely on CO2 concentrating mechanisms (CCMs) to assimilate carbon. Although many CCM proteins have been identified, a systematic screen of the components of CCMs is lacking. Here, we performed a genome-wide barcoded transposon screen to identify essential and CCM-related genes in the γ-proteobacterium Halothiobacillus neapolitanus. Screening revealed that the CCM comprises at least 17 and probably no more than 25 genes, most of which are encoded in 3 operons. Two of these operons (DAB1 and DAB2) contain a two-gene locus that encodes a domain of unknown function (Pfam: PF10070) and a putative cation transporter (Pfam: PF00361). Physiological and biochemical assays demonstrated that these proteins-which we name DabA and DabB, for DABs accumulate bicarbonate-assemble into a heterodimeric complex, which contains a putative β-carbonic anhydrase-like active site and functions as an energy-coupled inorganic carbon (Ci) pump. Interestingly, DAB operons are found in a diverse range of bacteria and archaea. We demonstrate that functional DABs are present in the human pathogens Bacillus anthracis and Vibrio cholerae. On the basis of these results, we propose that DABs constitute a class of energized Ci pumps and play a critical role in the metabolism of Ci throughout prokaryotic phyla.
Collapse
Affiliation(s)
- John J Desmarais
- Department of Molecular and Cell Biology, University of California, Berkeley, CA, USA
| | - Avi I Flamholz
- Department of Molecular and Cell Biology, University of California, Berkeley, CA, USA
| | - Cecilia Blikstad
- Department of Molecular and Cell Biology, University of California, Berkeley, CA, USA
| | - Eli J Dugan
- Department of Molecular and Cell Biology, University of California, Berkeley, CA, USA
| | - Thomas G Laughlin
- Department of Molecular and Cell Biology, University of California, Berkeley, CA, USA
| | - Luke M Oltrogge
- Department of Molecular and Cell Biology, University of California, Berkeley, CA, USA
| | - Allen W Chen
- Department of Chemistry, University of California, Berkeley, CA, USA
| | - Kelly Wetmore
- Environmental Genomics and Systems Biology Division, Lawrence Berkeley National Laboratory, Berkeley, CA, USA
| | - Spencer Diamond
- Department of Earth and Planetary Science, University of California, Berkeley, CA, USA
| | - Joy Y Wang
- Department of Chemistry, University of California, Berkeley, CA, USA
| | - David F Savage
- Department of Molecular and Cell Biology, University of California, Berkeley, CA, USA.
| |
Collapse
|
29
|
Probing the rice Rubisco-Rubisco activase interaction via subunit heterooligomerization. Proc Natl Acad Sci U S A 2019; 116:24041-24048. [PMID: 31712424 DOI: 10.1073/pnas.1914245116] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
During photosynthesis the AAA+ protein and essential molecular chaperone Rubisco activase (Rca) constantly remodels inhibited active sites of the CO2-fixing enzyme Rubisco (ribulose 1,5-bisphosphate carboxylase/oxygenase) to release tightly bound sugar phosphates. Higher plant Rca is a crop improvement target, but its mechanism remains poorly understood. Here we used structure-guided mutagenesis to probe the Rubisco-interacting surface of rice Rca. Mutations in Ser-23, Lys-148, and Arg-321 uncoupled adenosine triphosphatase and Rca activity, implicating them in the Rubisco interaction. Mutant doping experiments were used to evaluate a suite of known Rubisco-interacting residues for relative importance in the context of the functional hexamer. Hexamers containing some subunits that lack the Rubisco-interacting N-terminal domain displayed a ∼2-fold increase in Rca function. Overall Rubisco-interacting residues located toward the rim of the hexamer were found to be less critical to Rca function than those positioned toward the axial pore. Rca is a key regulator of the rate-limiting CO2-fixing reactions of photosynthesis. A detailed functional understanding will assist the ongoing endeavors to enhance crop CO2 assimilation rate, growth, and yield.
Collapse
|
30
|
Rubisco activation by wheat Rubisco activase isoform 2β is insensitive to inhibition by ADP. Biochem J 2019; 476:2595-2606. [PMID: 31471529 DOI: 10.1042/bcj20190110] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2019] [Revised: 08/28/2019] [Accepted: 08/30/2019] [Indexed: 11/17/2022]
Abstract
Rubisco activase (Rca) is a catalytic chaperone that remodels the active site, promotes the release of inhibitors and restores catalytic competence to Rubisco. Rca activity and its consequent effect on Rubisco activation and photosynthesis are modulated by changes to the chloroplast environment induced by fluctuations in light levels that reach the leaf, including redox status and adenosine diphosphate (ADP)/adenosine triphosphate (ATP) ratio. The Triticum aestivum (wheat) genome encodes for three Rca protein isoforms: 1β (42.7 kDa), 2β (42.2 kDa) and 2α (46.0 kDa). The regulatory properties of these isoforms were characterised by measuring rates of Rubisco activation and ATP hydrolysis by purified recombinant Rca proteins in the presence of physiological ADP/ATP ratios. ATP hydrolysis by all three isoforms was sensitive to inhibition by increasing amounts of ADP in the assay. In contrast, Rubisco activation activity of Rca 2β was insensitive to ADP inhibition, while Rca 1β and 2α were inhibited. Two double and one quadruple site-directed mutants were designed to elucidate if differences in the amino acid sequences between Rca 1β and 2β could explain the differences in ADP sensitivity. Changing two amino acids in Rca 2β to the corresponding residues in 1β (T358K & Q362E) resulted in significant inhibition of Rubisco activation in presence of ADP. The results show that the wheat Rca isoforms differ in their regulatory properties and that amino acid changes in the C domain influence ADP sensitivity. Advances in the understanding of Rubisco regulation will aid efforts to improve the efficiency of photosynthetic CO2 assimilation.
Collapse
|
31
|
Scafaro AP, Bautsoens N, den Boer B, Van Rie J, Gallé A. A Conserved Sequence from Heat-Adapted Species Improves Rubisco Activase Thermostability in Wheat. PLANT PHYSIOLOGY 2019; 181:43-54. [PMID: 31189658 PMCID: PMC6716234 DOI: 10.1104/pp.19.00425] [Citation(s) in RCA: 42] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/05/2019] [Accepted: 05/31/2019] [Indexed: 05/06/2023]
Abstract
The central enzyme of photosynthesis, Rubisco, is regulated by Rubisco activase (Rca). Photosynthesis is impaired during heat stress, and this limitation is often attributed to the heat-labile nature of Rca. We characterized gene expression and protein thermostability for the three Rca isoforms present in wheat (Triticum aestivum), namely TaRca1-β, TaRca2-α, and TaRca2-β. Furthermore, we compared wheat Rca with one of the two Rca isoforms from rice (Oryza sativa; OsRca-β) and Rca from other species adapted to warm environments. The TaRca1 gene was induced, whereas TaRca2 was suppressed by heat stress. The TaRca2 isoforms were sensitive to heat degradation, with thermal midpoints of 35°C ± 0.3°C, the temperature at which Rubisco activation velocity by Rca was halved. By contrast, TaRca1-β was more thermotolerant, with a thermal midpoint of 42°C, matching that of rice OsRca-β. Mutations of the TaRca2-β isoform based on sequence alignment of the thermostable TaRca1-β from wheat, OsRca-β from rice, and a consensus sequence representing Rca from warm-adapted species enabled the identification of 11 amino acid substitutions that improved its thermostability by greater than 7°C without a reduction in catalytic velocity at a standard 25°C. Protein structure modeling and mutational analysis suggested that the thermostability of these mutational variants arises from monomeric and not oligomeric thermal stabilization. These results provide a mechanism for improving the heat stress tolerance of photosynthesis in wheat and potentially other species, which is a desirable outcome considering the likelihood that crops will face more frequent heat stress conditions over the coming decades.
Collapse
Affiliation(s)
- Andrew P Scafaro
- BASF Agricultural Solutions, Ghent 9052, Belgium
- Australian Research Council Centre of Excellence in Plant Energy Biology, Research School of Biology, Australian National University, Canberra, Australian Capital Territory 2601, Australia
| | | | | | | | | |
Collapse
|
32
|
Annunziata MG. Enhancing Wheat Rubisco Activase Thermostability by Mutagenesis of Conserved Residues from Heat-Adapted Species. PLANT PHYSIOLOGY 2019; 181:3. [PMID: 31467136 PMCID: PMC6716247 DOI: 10.1104/pp.19.00794] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
|
33
|
Goh FQY, Jeyakani J, Tipthara P, Cazenave-Gassiot A, Ghosh R, Bogard N, Yeo Z, Wong GKS, Melkonian M, Wenk MR, Clarke ND. Gains and losses of metabolic function inferred from a phylotranscriptomic analysis of algae. Sci Rep 2019; 9:10482. [PMID: 31324835 PMCID: PMC6642084 DOI: 10.1038/s41598-019-46869-3] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2019] [Accepted: 07/05/2019] [Indexed: 11/25/2022] Open
Abstract
Hidden Markov models representing 167 protein sequence families were used to infer the presence or absence of homologs within the transcriptomes of 183 algal species/strains. Statistical analyses of the distribution of HMM hits across major clades of algae, or at branch points on the phylogenetic tree of 98 chlorophytes, confirmed and extended known cases of metabolic loss and gain, most notably the loss of the mevalonate pathway for terpenoid synthesis in green algae but not, as we show here, in the streptophyte algae. Evidence for novel events was found as well, most remarkably in the recurrent and coordinated gain or loss of enzymes for the glyoxylate shunt. We find, as well, a curious pattern of retention (or re-gain) of HMG-CoA synthase in chlorophytes that have otherwise lost the mevalonate pathway, suggesting a novel, co-opted function for this enzyme in select lineages. Finally, we find striking, phylogenetically linked distributions of coding sequences for three pathways that synthesize the major membrane lipid phosphatidylcholine, and a complementary phylogenetic distribution pattern for the non-phospholipid DGTS (diacyl-glyceryl-trimethylhomoserine). Mass spectrometric analysis of lipids from 25 species was used to validate the inference of DGTS synthesis from sequence data.
Collapse
Affiliation(s)
- Falicia Qi Yun Goh
- Yale-NUS College Singapore, 138527, Singapore, Singapore.,Computational and Systems Biology, Genome Institute of Singapore, Singapore, 138672, Singapore
| | - Justin Jeyakani
- Computational and Systems Biology, Genome Institute of Singapore, Singapore, 138672, Singapore
| | - Phornpimon Tipthara
- Computational and Systems Biology, Genome Institute of Singapore, Singapore, 138672, Singapore
| | - Amaury Cazenave-Gassiot
- Department of Biochemistry, Yong Loo Lin School of Medicine National University of Singapore, Singapore, 117596, Singapore
| | - Rajoshi Ghosh
- Computational and Systems Biology, Genome Institute of Singapore, Singapore, 138672, Singapore
| | - Nicholas Bogard
- Computational and Systems Biology, Genome Institute of Singapore, Singapore, 138672, Singapore
| | - Zhenxuan Yeo
- Yale-NUS College Singapore, 138527, Singapore, Singapore.,Computational and Systems Biology, Genome Institute of Singapore, Singapore, 138672, Singapore
| | - Gane Ka-Shu Wong
- Department of Biological Sciences, University of Alberta, Edmonton, T6G 2E9, Canada.,Department of Medicine, University of Alberta, Edmonton, T6G 2E1, Canada.,BGI-Shenzhen, Shenzhen, 518083, China
| | - Michael Melkonian
- Botanical Institute, Cologne Biocenter, University of Cologne, 50674, Cologne, Germany
| | - Markus R Wenk
- Department of Biochemistry, Yong Loo Lin School of Medicine National University of Singapore, Singapore, 117596, Singapore
| | - Neil D Clarke
- Yale-NUS College Singapore, 138527, Singapore, Singapore. .,Computational and Systems Biology, Genome Institute of Singapore, Singapore, 138672, Singapore. .,Department of Biological Sciences, National University of Singapore, Singapore, 117543, Singapore.
| |
Collapse
|
34
|
Wilson RH, Thieulin-Pardo G, Hartl FU, Hayer-Hartl M. Improved recombinant expression and purification of functional plant Rubisco. FEBS Lett 2019; 593:611-621. [PMID: 30815863 PMCID: PMC6593764 DOI: 10.1002/1873-3468.13352] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2019] [Revised: 02/24/2019] [Accepted: 02/25/2019] [Indexed: 12/22/2022]
Abstract
Improving the performance of the key photosynthetic enzyme Ribulose-1,5-bisphosphate carboxylase/oxygenase (Rubisco) by protein engineering is a critical strategy for increasing crop yields. The extensive chaperone requirement of plant Rubisco for folding and assembly has long been an impediment to this goal. Production of plant Rubisco in Escherichia coli requires the coexpression of the chloroplast chaperonin and four assembly factors. Here, we demonstrate that simultaneous expression of Rubisco and chaperones from a T7 promotor produces high levels of functional enzyme. Expressing the small subunit of Rubisco with a C-terminal hexahistidine-tag further improved assembly, resulting in a ~ 12-fold higher yield than the previously published procedure. The expression system described here provides a platform for the efficient production and engineering of plant Rubisco.
Collapse
Affiliation(s)
- Robert H Wilson
- Chaperonin-assisted Protein Folding Group, Max Planck Institute of Biochemistry, Martinsried, Germany
| | - Gabriel Thieulin-Pardo
- Chaperonin-assisted Protein Folding Group, Max Planck Institute of Biochemistry, Martinsried, Germany
| | - Franz-Ulrich Hartl
- Cellular Biochemistry Group, Max Planck Institute of Biochemistry, Martinsried, Germany
| | - Manajit Hayer-Hartl
- Chaperonin-assisted Protein Folding Group, Max Planck Institute of Biochemistry, Martinsried, Germany
| |
Collapse
|
35
|
Serban AJ, Breen IL, Bui HQ, Levitus M, Wachter RM. Assembly-disassembly is coupled to the ATPase cycle of tobacco Rubisco activase. J Biol Chem 2018; 293:19451-19465. [PMID: 30352875 PMCID: PMC6302163 DOI: 10.1074/jbc.ra118.005047] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2018] [Revised: 10/09/2018] [Indexed: 11/06/2022] Open
Abstract
The carbon-fixing activity of enzyme ribulose-1,5-bisphosphate carboxylase/oxygenase (Rubisco) is regulated by Rubisco activase (Rca), a ring-forming ATPase that catalyzes inhibitor release. For higher plant Rca, the catalytic roles played by different oligomeric species have remained obscure. Here, we utilized fluorescence-correlation spectroscopy to estimate dissociation constants for the dimer-tetramer, tetramer-hexamer, hexamer-12-mer, and higher-order assembly equilibria of tobacco Rca. A comparison of oligomer composition with ATPase activity provided evidence that assemblies larger than hexamers are hydrolytically inactive. Therefore, supramolecular aggregates may serve as storage forms at low-energy charge. We observed that the tetramer accumulates only when both substrate and product nucleotides are bound. During rapid ATP turnover, about one in six active sites was occupied by ADP, and ∼36% of Rca was tetrameric. The steady-state catalytic rate reached a maximum between 0.5 and 2.5 μm Rca. In this range, significant amounts of dimers, tetramers, and hexamers coexisted, although none could fully account for the observed activity profile. Therefore, we propose that dynamic assembly-disassembly partakes in the ATPase cycle. According to this model, the association of dimers with tetramers generates a hexamer that forms a closed ring at high ATP and magnesium levels. Upon hydrolysis and product release, the toroid breaks open and dissociates into a dimer and tetramer, which may be coupled to Rubisco remodeling. Although a variant bearing the R294V substitution assembled in much the same way, highly stabilized states could be generated by binding of a transition-state analog. A tight-binding pre-hydrolysis state appears to become more accessible in thermally labile Rcas.
Collapse
Affiliation(s)
- Andrew J Serban
- From the School of Molecular Sciences
- Center for Bioenergy and Photosynthesis
- Biodesign Center for Applied Structural Discovery, and
| | - Isabella L Breen
- From the School of Molecular Sciences
- Center for Bioenergy and Photosynthesis
- Biodesign Center for Applied Structural Discovery, and
| | - Hoang Q Bui
- From the School of Molecular Sciences
- Center for Bioenergy and Photosynthesis
- Biodesign Center for Applied Structural Discovery, and
| | - Marcia Levitus
- From the School of Molecular Sciences,
- the Biodesign Center for Single Molecule Biophysics, Arizona State University, Tempe, Arizona 85287
| | - Rebekka M Wachter
- From the School of Molecular Sciences,
- Center for Bioenergy and Photosynthesis
- Biodesign Center for Applied Structural Discovery, and
| |
Collapse
|
36
|
Salesse-Smith CE, Sharwood RE, Busch FA, Kromdijk J, Bardal V, Stern DB. Overexpression of Rubisco subunits with RAF1 increases Rubisco content in maize. NATURE PLANTS 2018; 4:802-810. [PMID: 30287949 DOI: 10.1038/s41477-018-0252-4] [Citation(s) in RCA: 95] [Impact Index Per Article: 15.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/11/2018] [Accepted: 08/15/2018] [Indexed: 05/21/2023]
Abstract
Rubisco catalyses a rate-limiting step in photosynthesis and has long been a target for improvement due to its slow turnover rate. An alternative to modifying catalytic properties of Rubisco is to increase its abundance within C4 plant chloroplasts, which might increase activity and confer a higher carbon assimilation rate. Here, we overexpress the Rubisco large (LS) and small (SS) subunits with the Rubisco assembly chaperone RUBISCO ASSEMBLY FACTOR 1 (RAF1). While overexpression of LS and/or SS had no discernable impact on Rubisco content, addition of RAF1 overexpression resulted in a >30% increase in Rubisco content. Gas exchange showed a 15% increase in CO2 assimilation (ASAT) in UBI-LSSS-RAF1 transgenic plants, which correlated with increased fresh weight and in vitro Vcmax calculations. The divergence of Rubisco content and assimilation could be accounted for by the Rubisco activation state, which decreased up to 23%, suggesting that Rubisco activase may be limiting Vcmax, and impinging on the realization of photosynthetic potential from increased Rubisco content.
Collapse
Affiliation(s)
| | - Robert E Sharwood
- Research School of Biology, The Australian National University, Canberra, Australian Capital Territory, Australia
| | - Florian A Busch
- Research School of Biology, The Australian National University, Canberra, Australian Capital Territory, Australia
| | - Johannes Kromdijk
- Carl R. Woese Institute for Genomic Biology, University of Illinois, Urbana, IL, USA
| | | | | |
Collapse
|
37
|
Vitlin Gruber A, Feiz L. Rubisco Assembly in the Chloroplast. Front Mol Biosci 2018; 5:24. [PMID: 29594130 PMCID: PMC5859369 DOI: 10.3389/fmolb.2018.00024] [Citation(s) in RCA: 37] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2017] [Accepted: 02/27/2018] [Indexed: 01/13/2023] Open
Abstract
Ribulose-1,5-bisphosphate carboxylase/oxygenase (Rubisco) catalyzes the rate-limiting step in the Calvin-Benson cycle, which transforms atmospheric carbon into a biologically useful carbon source. The slow catalytic rate of Rubisco and low substrate specificity necessitate the production of high levels of this enzyme. In order to engineer a more efficient plant Rubisco, we need to better understand its folding and assembly process. Form I Rubisco, found in green algae and vascular plants, is a hexadecamer composed of 8 large subunits (RbcL), encoded by the chloroplast genome and 8 small, nuclear-encoded subunits (RbcS). Unlike its cyanobacterial homolog, which can be reconstituted in vitro or in E. coli, assisted by bacterial chaperonins (GroEL-GroES) and the RbcX chaperone, biogenesis of functional chloroplast Rubisco requires Cpn60-Cpn20, the chloroplast homologs of GroEL-GroES, and additional auxiliary factors, including Rubisco accumulation factor 1 (Raf1), Rubisco accumulation factor 2 (Raf2) and Bundle sheath defective 2 (Bsd2). The discovery and characterization of these factors paved the way for Arabidopsis Rubisco assembly in E. coli. In the present review, we discuss the uniqueness of hetero-oligomeric chaperonin complex for RbcL folding, as well as the sequential or concurrent actions of the post-chaperonin chaperones in holoenzyme assembly. The exact stages at which each assembly factor functions are yet to be determined. Expression of Arabidopsis Rubisco in E. coli provided some insight regarding the potential roles for Raf1 and RbcX in facilitating RbcL oligomerization, for Bsd2 in stabilizing the oligomeric core prior to holoenzyme assembly, and for Raf2 in interacting with both RbcL and RbcS. In the long term, functional characterization of each known factor along with the potential discovery and characterization of additional factors will set the stage for designing more efficient plants, with a greater biomass, for use in biofuels and sustenance.
Collapse
Affiliation(s)
- Anna Vitlin Gruber
- Department of Molecular, Cell and Developmental Biology, University of California, Los Angeles, Los Angeles, CA, United States
| | - Leila Feiz
- Boyce Thompson Institute, Cornell University, Ithaca, NY, United States
| |
Collapse
|
38
|
Saifi SK, Passricha N, Tuteja R, Tuteja N. Stress-induced Oryza sativa RuvBL1a is DNA-independent ATPase and unwinds DNA duplex in 3' to 5' direction. PROTOPLASMA 2018; 255:669-684. [PMID: 29103092 DOI: 10.1007/s00709-017-1178-9] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/04/2017] [Accepted: 10/20/2017] [Indexed: 06/07/2023]
Abstract
RuvB, a member of AAA+ (ATPases Associated with diverse cellular Activities) superfamily of proteins, is essential, highly conserved and multifunctional in nature as it is involved in DNA damage repair, mitotic assembly, switching of histone variants and assembly of telomerase core complex. RuvB family is widely studied in various systems such as Escherichia coli, yeast, human, Drosophila, Plasmodium falciparum and mouse, but not well studied in plants. We have studied the transcript level of rice homologue of RuvB gene (OsRuvBL1a) under various abiotic stress conditions, and the results suggest that it is upregulated under salinity, cold and heat stress. Therefore, the OsRuvBL1a protein was characterized using in silico and biochemical approaches. In silico study confirmed the presence of all the four characteristic motifs of AAA+ superfamily-Walker A, Walker B, Sensor I and Sensor II. Structurally, OsRuvBL1a is similar to RuvB1 from Chaetomium thermophilum. The purified recombinant OsRuvBL1a protein shows unique DNA-independent ATPase activity. Using site-directed mutagenesis, the importance of two conserved motifs (Walker B and Sensor I) in ATPase activity has been also reported with mutants D302N and N332H. The OsRuvBL1a protein unwinds the duplex DNA in the 3' to 5' direction. The presence of unique DNA-independent ATPase and DNA unwinding activities of OsRuvBL1a protein and upregulation of its transcript under abiotic stress conditions suggest its involvement in multiple cellular pathways. The first detailed characterization of plant RuvBL1a in this study may provide important contribution in exploiting the role of RuvB for developing the stress tolerant plants of agricultural importance.
Collapse
Affiliation(s)
- Shabnam K Saifi
- International Centre for Genetic Engineering and Biotechnology, Aruna Asaf Ali Marg, New Delhi, 110067, India
| | - Nishat Passricha
- International Centre for Genetic Engineering and Biotechnology, Aruna Asaf Ali Marg, New Delhi, 110067, India
| | - Renu Tuteja
- International Centre for Genetic Engineering and Biotechnology, Aruna Asaf Ali Marg, New Delhi, 110067, India
| | - Narendra Tuteja
- International Centre for Genetic Engineering and Biotechnology, Aruna Asaf Ali Marg, New Delhi, 110067, India.
| |
Collapse
|
39
|
Liu D, Ramya RCS, Mueller-Cajar O. Surveying the expanding prokaryotic Rubisco multiverse. FEMS Microbiol Lett 2018; 364:3983162. [PMID: 28854711 DOI: 10.1093/femsle/fnx156] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2017] [Accepted: 07/19/2017] [Indexed: 11/12/2022] Open
Abstract
The universal, but catalytically modest, CO2-fixing enzyme Rubisco is currently experiencing intense interest by researchers aiming to enhance crop photosynthesis. These efforts are mostly focused on the highly conserved hexadecameric enzyme found in land plants. In comparison, prokaryotic organisms harbor a far greater diversity in Rubisco forms. Recent work towards improving our appreciation of microbial Rubisco properties and harnessing their potential is surveyed. New structural models are providing informative glimpses into catalytic subtleties and diverse oligomeric states. Ongoing characterization is informing us about the conservation of constraints, such as sugar phosphate inhibition and the associated dependence on Rubisco activase helper proteins. Prokaryotic Rubiscos operate under a far wider range of metabolic contexts than the photosynthetic function of higher plant enzymes. Relaxed selection pressures may have resulted in the exploration of a larger volume of sequence space than permitted in organisms performing oxygenic photosynthesis. To tap into the potential of microbial Rubiscos, in vivo selection systems are being used to discover functional metagenomic Rubiscos. Various directed evolution systems to optimize their function have been developed. It is anticipated that this approach will provide access to biotechnologically valuable enzymes that cannot be encountered in the higher plant Rubisco space.
Collapse
Affiliation(s)
- Di Liu
- School of Biological Sciences, Nanyang Technological University, 60 Nanyang Drive, Singapore 637551, Singapore
| | | | - Oliver Mueller-Cajar
- School of Biological Sciences, Nanyang Technological University, 60 Nanyang Drive, Singapore 637551, Singapore
| |
Collapse
|
40
|
Experimental evolution and proximate mechanisms in biology. Synth Syst Biotechnol 2017; 2:253-258. [PMID: 29552649 PMCID: PMC5851904 DOI: 10.1016/j.synbio.2017.10.004] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2017] [Revised: 10/16/2017] [Accepted: 10/20/2017] [Indexed: 11/23/2022] Open
Abstract
Biological functions – studied by molecular, systems and behavioral biology – are referred to as proximate mechanisms. Why and how they have emerged from the course of evolution are referred to as ultimate mechanisms. Despite the conceptual and technical schism between the disciplines that focus on each, studies from one side can benefit the other. Experimental evolution is an emerging field at the crossroads of functional and evolutionary biology. Herein microorganisms and mammalian cell lines evolve in well-controlled laboratory environments over multiple generations. Phenotypic changes arising from the process are then characterized in genetics and function to understand the evolutionary process. While providing empirical tests to evolutionary questions, such studies also offer opportunities of new insights into proximate mechanisms. Experimental evolution optimizes biological systems by means of adaptation; the adapted systems with their mutations present unique perturbed states of the systems that generate new and often unexpected output/performance. Hence, learning about these states not only adds to but also might deepen knowledge on the proximate processes. To demonstrate this point, five examples in experimental evolution are introduced, and their relevance to functional biology explicated. In some examples, from evolution experiments, updates were made to known proximate processes – gene regulation and cell polarization. In some examples, new contexts were found for known proximate processes – cell division and drug resistance of cancer. In one example, a new cellular mechanism was discovered. These cases identify ways the approach of experimental evolution can be used to ask questions in functional biology.
Collapse
|
41
|
Hayer-Hartl M. From chaperonins to Rubisco assembly and metabolic repair. Protein Sci 2017; 26:2324-2333. [PMID: 28960553 DOI: 10.1002/pro.3309] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2017] [Revised: 09/21/2017] [Accepted: 09/25/2017] [Indexed: 01/13/2023]
Abstract
Ribulose-1,5-bisphosphate carboxylase/oxygenase (Rubisco) mediates the fixation of atmospheric CO2 in photosynthesis by catalyzing the carboxylation of the 5-carbon sugar ribulose-1,5-bisphosphate (RuBP). Despite its pivotal role, Rubisco is an inefficient enzyme and thus has been a key target for bioengineering. However, efforts to increase crop yields by Rubisco engineering remain unsuccessful, due in part to the complex machinery of molecular chaperones required for Rubisco biogenesis and metabolic repair. While the large subunit of Rubisco generally requires the chaperonin system for folding, the evolution of the hexadecameric Rubisco from its dimeric precursor resulted in the dependence on an array of additional factors required for assembly. Moreover, Rubisco function can be inhibited by a range of sugar-phosphate ligands. Metabolic repair of Rubisco depends on remodeling by the ATP-dependent Rubisco activase and hydrolysis of inhibitors by specific phosphatases. This review highlights our work toward understanding the structure and mechanism of these auxiliary machineries.
Collapse
Affiliation(s)
- Manajit Hayer-Hartl
- Department of Cellular Biochemistry, Max Planck Institute of Biochemistry, Martinsried, Germany
| |
Collapse
|
42
|
Erb TJ, Zarzycki J. A short history of RubisCO: the rise and fall (?) of Nature's predominant CO 2 fixing enzyme. Curr Opin Biotechnol 2017; 49:100-107. [PMID: 28843191 DOI: 10.1016/j.copbio.2017.07.017] [Citation(s) in RCA: 146] [Impact Index Per Article: 20.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2017] [Revised: 07/26/2017] [Accepted: 07/26/2017] [Indexed: 11/18/2022]
Abstract
Ribulose-1,5-bisphosphate carboxylase/oxygenase (RubisCO) is arguably one of the most abundant proteins in the biosphere and a key enzyme in the global carbon cycle. Although RubisCO has been intensively studied, its evolutionary origins and rise as Nature's most dominant carbon dioxide (CO2)-fixing enzyme still remain in the dark. In this review we will bring together biochemical, structural, physiological, microbiological, as well as phylogenetic data to speculate on the evolutionary roots of the CO2-fixation reaction of RubisCO, the emergence of RubisCO-based autotrophic CO2-fixation in the context of the Calvin-Benson-Bassham cycle, and the further evolution of RubisCO into the 'RubisCOsome', a complex of various proteins assembling and interacting with the enzyme to improve its operational capacity (functionality) under different biological and environmental conditions.
Collapse
Affiliation(s)
- Tobias J Erb
- Max Planck Institute for Terrestrial Microbiology, Department of Biochemistry and Synthetic Metabolism, Karl-von-Frisch-Str. 10, 35043 Marburg, Germany.
| | - Jan Zarzycki
- Max Planck Institute for Terrestrial Microbiology, Department of Biochemistry and Synthetic Metabolism, Karl-von-Frisch-Str. 10, 35043 Marburg, Germany
| |
Collapse
|
43
|
Shivhare D, Mueller-Cajar O. In Vitro Characterization of Thermostable CAM Rubisco Activase Reveals a Rubisco Interacting Surface Loop. PLANT PHYSIOLOGY 2017; 174:1505-1516. [PMID: 28546437 PMCID: PMC5490924 DOI: 10.1104/pp.17.00554] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/21/2017] [Accepted: 05/24/2017] [Indexed: 05/19/2023]
Abstract
To maintain metabolic flux through the Calvin-Benson-Bassham cycle in higher plants, dead-end inhibited complexes of Rubisco must constantly be engaged and remodeled by the molecular chaperone Rubisco activase (Rca). In C3 plants, the thermolability of Rca is responsible for the deactivation of Rubisco and reduction of photosynthesis at moderately elevated temperatures. We reasoned that crassulacean acid metabolism (CAM) plants must possess thermostable Rca to support Calvin-Benson-Bassham cycle flux during the day when stomata are closed. A comparative biochemical characterization of rice (Oryza sativa) and Agave tequilana Rca isoforms demonstrated that the CAM Rca isoforms are approximately10°C more thermostable than the C3 isoforms. Agave Rca also possessed a much higher in vitro biochemical activity, even at low assay temperatures. Mixtures of rice and agave Rca form functional hetero-oligomers in vitro, but only the rice isoforms denature at nonpermissive temperatures. The high thermostability and activity of agave Rca mapped to the N-terminal 244 residues. A Glu-217-Gln amino acid substitution was found to confer high Rca activity to rice Rca Further mutational analysis suggested that Glu-217 restricts the flexibility of the α4-β4 surface loop that interacts with Rubisco via Lys-216. CAM plants thus promise to be a source of highly functional, thermostable Rca candidates for thermal fortification of crop photosynthesis. Careful characterization of their properties will likely reveal further protein-protein interaction motifs to enrich our mechanistic model of Rca function.
Collapse
Affiliation(s)
- Devendra Shivhare
- School of Biological Sciences, Nanyang Technological University, Singapore 637551, Singapore
| | - Oliver Mueller-Cajar
- School of Biological Sciences, Nanyang Technological University, Singapore 637551, Singapore
| |
Collapse
|