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Faisal M, Sarnaik AP, Kannoju N, Hajinajaf N, Asad MJ, Davis RW, Varman AM. RuBisCO activity assays: a simplified biochemical redox approach for in vitro quantification and an RNA sensor approach for in vivo monitoring. Microb Cell Fact 2024; 23:83. [PMID: 38486280 PMCID: PMC10938803 DOI: 10.1186/s12934-024-02357-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2023] [Accepted: 03/04/2024] [Indexed: 03/18/2024] Open
Abstract
BACKGROUND Ribulose-1,5-bisphosphate carboxylase/oxygenase (RuBisCO) is the most abundant soluble protein in nature. Extensive studies have been conducted for improving its activity in photosynthesis through approaches like protein engineering. Concurrently, multiple biochemical and radiolabeling assays have been developed for determining its activity. Although these existing assays yield reliable results, they require addition of multiple external components, rendering them less convenient and expensive. Therefore, in this study, we have developed two relatively cheaper, convenient, and easily reproducible assays for quantitative and qualitative estimation of RuBisCO activity. RESULTS We simplified a contemporary NADH based spectrophotometric RuBisCO assay by using cyanobacterial cell lysate as the source for Calvin cycle enzymes. We analyzed the influence of inorganic carbon substrates, CO2 and NaHCO3, and varying protein concentrations on RuBisCO activity. Ribulose-1,5-bisphosphate (RuBP) consumption rates for the cultures grown under 5% CO2 were 5-7 times higher than the ones grown with 20 mM NaHCO3, at different protein concentrations. The difference could be due to the impaired activity of carbonic anhydrase in the cell lysate, which is required for the conversion of HCO3- to CO2. The highest RuBisCO activity of 2.13 nmol of NAD+/ µg of Chl-a/ min was observed with 50 µg of protein and 5% CO2. Additionally, we developed a novel RNA-sensor based fluorescence assay that is based on the principle of tracking the kinetics of ATP hydrolysis to ADP during the conversion of 3-phosphoglycerate (3-PG) to 1,3-bisphosphoglycerate (1,3-BPG) in the Calvin cycle. Under in vitro conditions, the fluorometric assay exhibited ~ 3.4-fold slower reaction rate (0.37 min-1) than the biochemical assay when using 5% CO2. We also confirmed the in vivo application of this assay, where increase in the fluorescence was observed with the recombinant strain of Synechocystis sp. PCC 6803 (SSL142) expressing the ADP-specific RNA sensor, compared to the WT. In addition, SSL142 exhibited three-fold higher fluorescence when supplemented with 20 mM NaHCO3 as compared to the cells that were grown without NaHCO3 supplementation. CONCLUSIONS Overall, we have developed a simplified biochemical assay for monitoring RuBisCO activity and demonstrated that it can provide reliable results as compared to the prior literature. Furthermore, the biochemical assay using 5% CO2 (100% relative activity) provided faster RuBP consumption rate compared to the biochemical assay utilizing 20 mM NaHCO3 (30.70% relative activity) and the in vitro fluorometric assay using 5% CO2 (29.64% relative activity). Therefore, the absorbance-based biochemical assay using 5% CO2 or higher would be suitable for in vitro quantification of the RuBisCO activity. On the other hand, the RNA-sensor based in vivo fluorometric assay can be applied for qualitative analysis and be used for high-throughput screening of RuBisCO variants. As RuBisCO is an enzyme shared amongst all the photoautotrophs, the assays developed in this study can easily be extended for analyzing the RuBisCO activities even in microalgae and higher plants.
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Affiliation(s)
- Muhammad Faisal
- Chemical Engineering, School for Engineering of Matter, Transport and Energy (SEMTE), Arizona State University, Tempe, AZ, 85281, USA
- University Institute of Biochemistry and Biotechnology, PMAS-Arid Agriculture University Rawalpindi, Rawalpindi, 46000, Pakistan
| | - Aditya P Sarnaik
- Chemical Engineering, School for Engineering of Matter, Transport and Energy (SEMTE), Arizona State University, Tempe, AZ, 85281, USA
| | - Nandini Kannoju
- Chemical Engineering, School for Engineering of Matter, Transport and Energy (SEMTE), Arizona State University, Tempe, AZ, 85281, USA
| | - Nima Hajinajaf
- Chemical Engineering, School for Engineering of Matter, Transport and Energy (SEMTE), Arizona State University, Tempe, AZ, 85281, USA
| | - Muhammad Javaid Asad
- University Institute of Biochemistry and Biotechnology, PMAS-Arid Agriculture University Rawalpindi, Rawalpindi, 46000, Pakistan
| | - Ryan W Davis
- Sandia National Laboratories, Livermore, CA, USA
| | - Arul M Varman
- Chemical Engineering, School for Engineering of Matter, Transport and Energy (SEMTE), Arizona State University, Tempe, AZ, 85281, USA.
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2
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Minagawa J, Dann M. Extracellular CahB1 from Sodalinema gerasimenkoae IPPAS B-353 Acts as a Functional Carboxysomal β-Carbonic Anhydrase in Synechocystis sp. PCC6803. PLANTS (BASEL, SWITZERLAND) 2023; 12:265. [PMID: 36678979 PMCID: PMC9865033 DOI: 10.3390/plants12020265] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/23/2022] [Revised: 12/27/2022] [Accepted: 01/03/2023] [Indexed: 06/17/2023]
Abstract
Cyanobacteria mostly rely on the active uptake of hydrated CO2 (i.e., bicarbonate ions) from the surrounding media to fuel their inorganic carbon assimilation. The dehydration of bicarbonate in close vicinity of RuBisCO is achieved through the activity of carboxysomal carbonic anhydrase (CA) enzymes. Simultaneously, many cyanobacterial genomes encode extracellular α- and β-class CAs (EcaA, EcaB) whose exact physiological role remains largely unknown. To date, the CahB1 enzyme of Sodalinema gerasimenkoae (formerly Microcoleus/Coleofasciculus chthonoplastes) remains the sole described active extracellular β-CA in cyanobacteria, but its molecular features strongly suggest it to be a carboxysomal rather than a secreted protein. Upon expression of CahB1 in Synechocystis sp. PCC6803, we found that its expression complemented the loss of endogenous CcaA. Moreover, CahB1 was found to localize to a carboxysome-harboring and CA-active cell fraction. Our data suggest that CahB1 retains all crucial properties of a cellular carboxysomal CA and that the secretion mechanism and/or the machinations of the Sodalinema gerasimenkoae carboxysome are different from those of Synechocystis.
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Affiliation(s)
- Jun Minagawa
- Division of Environmental Photobiology, National Institute for Basic Biology (NIBB), Aichi, Okazaki 444-8585, Japan
| | - Marcel Dann
- Division of Environmental Photobiology, National Institute for Basic Biology (NIBB), Aichi, Okazaki 444-8585, Japan
- Plant Molecular Biology, Ludwig-Maximilian University (LMU) Munich, 82152 Planegg, Germany
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3
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Cabello-Yeves PJ, Scanlan DJ, Callieri C, Picazo A, Schallenberg L, Huber P, Roda-Garcia JJ, Bartosiewicz M, Belykh OI, Tikhonova IV, Torcello-Requena A, De Prado PM, Millard AD, Camacho A, Rodriguez-Valera F, Puxty RJ. α-cyanobacteria possessing form IA RuBisCO globally dominate aquatic habitats. THE ISME JOURNAL 2022; 16:2421-2432. [PMID: 35851323 PMCID: PMC9477826 DOI: 10.1038/s41396-022-01282-z] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/25/2022] [Revised: 06/21/2022] [Accepted: 06/28/2022] [Indexed: 11/24/2022]
Abstract
RuBisCO (ribulose 1,5-bisphosphate carboxylase/oxygenase) is one the most abundant enzymes on Earth. Virtually all food webs depend on its activity to supply fixed carbon. In aerobic environments, RuBisCO struggles to distinguish efficiently between CO2 and O2. To compensate, organisms have evolved convergent solutions to concentrate CO2 around the active site. The genetic engineering of such inorganic carbon concentrating mechanisms (CCMs) into plants could help facilitate future global food security for humankind. In bacteria, the carboxysome represents one such CCM component, of which two independent forms exist: α and β. Cyanobacteria are important players in the planet's carbon cycle and the vast majority of the phylum possess a β-carboxysome, including most cyanobacteria used as laboratory models. The exceptions are the exclusively marine Prochlorococcus and Synechococcus that numerically dominate open ocean systems. However, the reason why marine systems favor an α-form is currently unknown. Here, we report the genomes of 58 cyanobacteria, closely related to marine Synechococcus that were isolated from freshwater lakes across the globe. We find all these isolates possess α-carboxysomes accompanied by a form 1A RuBisCO. Moreover, we demonstrate α-cyanobacteria dominate freshwater lakes worldwide. Hence, the paradigm of a separation in carboxysome type across the salinity divide does not hold true, and instead the α-form dominates all aquatic systems. We thus question the relevance of β-cyanobacteria as models for aquatic systems at large and pose a hypothesis for the reason for the success of the α-form in nature.
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Affiliation(s)
- Pedro J Cabello-Yeves
- Evolutionary Genomics Group, Departamento de Producción Vegetal y Microbiología, Universidad Miguel Hernández, San Juan de Alicante, Alicante, Spain.
| | - David J Scanlan
- School of Life Sciences, University of Warwick, Coventry, CV4 7AL, UK
| | - Cristiana Callieri
- National Research Council (CNR), Institute of Water Research (IRSA), Verbania, Italy
| | - Antonio Picazo
- Cavanilles Institute of Biodiversity and Evolutionary Biology, University of Valencia, E-46980 Paterna, Valencia, Spain
| | | | - Paula Huber
- Instituto Tecnológico de Chascomús (INTECH), UNSAM-CONICET., Av. Intendente Marino Km 8,200, 7130, Chascomús, Buenos Aires, Argentina
- Instituto Nacional de Limnología (INALI), CONICET-UNL., Ciudad Universitaria-Paraje el Pozo s/n, 3000, Santa Fé, Argentina
| | - Juan J Roda-Garcia
- Evolutionary Genomics Group, Departamento de Producción Vegetal y Microbiología, Universidad Miguel Hernández, San Juan de Alicante, Alicante, Spain
| | - Maciej Bartosiewicz
- Department of Environmental Sciences, University of Basel, Basel, Switzerland
| | - Olga I Belykh
- Limnological Institute, Russian Academy of Sciences, P.O. Box 278, 664033, Irkutsk, Russia
| | - Irina V Tikhonova
- Limnological Institute, Russian Academy of Sciences, P.O. Box 278, 664033, Irkutsk, Russia
| | | | | | - Andrew D Millard
- Department of Genetics and Genome Biology, University of Leicester, Leicester, LE1 7RH, UK
| | - Antonio Camacho
- Cavanilles Institute of Biodiversity and Evolutionary Biology, University of Valencia, E-46980 Paterna, Valencia, Spain
| | - Francisco Rodriguez-Valera
- Evolutionary Genomics Group, Departamento de Producción Vegetal y Microbiología, Universidad Miguel Hernández, San Juan de Alicante, Alicante, Spain
- Moscow Institute of Physics and Technology, 141701, Dolgoprudny, Russia
| | - Richard J Puxty
- School of Life Sciences, University of Warwick, Coventry, CV4 7AL, UK.
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Yang X, Yao S, An J, Jin H, Wang H, Tuo B. SLC26A6 and NADC‑1: Future direction of nephrolithiasis and calculus‑related hypertension research (Review). Mol Med Rep 2021; 24:745. [PMID: 34458928 DOI: 10.3892/mmr.2021.12385] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2021] [Accepted: 07/30/2021] [Indexed: 11/06/2022] Open
Abstract
Nephrolithiasis is the most common type of urinary system disease in developed countries, with high morbidity and recurrence rates. Nephrolithiasis is a serious health problem, which eventually leads to the loss of renal function and is closely related to hypertension. Modern medicine has adopted minimally invasive surgery for the management of kidney stones, but this does not resolve the root of the problem. Thus, nephrolithiasis remains a major public health issue, the causes of which remain largely unknown. Researchers have attempted to determine the causes and therapeutic targets of kidney stones and calculus‑related hypertension. Solute carrier family 26 member 6 (SLC26A6), a member of the well‑conserved solute carrier family 26, is highly expressed in the kidney and intestines, and it primarily mediates the transport of various anions, including OXa2‑, HCO3‑, Cl‑ and SO42‑, amongst others. Na+‑dependent dicarboxylate‑1 (NADC‑1) is the Na+‑carboxylate co‑transporter of the SLC13 gene family, which primarily mediates the co‑transport of Na+ and tricarboxylic acid cycle intermediates, such as citrate and succinate, amongst others. Studies have shown that Ca2+ oxalate kidney stones are the most prevalent type of kidney stones. Hyperoxaluria and hypocitraturia notably increase the risk of forming Ca2+ oxalate kidney stones, and the increase in succinate in the juxtaglomerular device can stimulate renin secretion and lead to hypertension. Whilst it is known that it is important to maintain the dynamic equilibrium of oxalate and citrate in the kidney, the synergistic molecular mechanisms underlying the transport of oxalate and citrate across kidney epithelial cells have undergone limited investigations. The present review examines the results from early reports studying oxalate transport and citrate transport in the kidney, describing the synergistic molecular mechanisms of SLC26A6 and NADC‑1 in the process of nephrolithiasis formation. A growing body of research has shown that nephrolithiasis is intricately associated with hypertension. Additionally, the recent investigations into the mediation of succinate via regulation of the synergistic molecular mechanism between the SLC26A6 and NADC‑1 transporters is summarized, revealing their functional role and their close association with the inositol triphosphate receptor‑binding protein to regulate blood pressure.
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Affiliation(s)
- Xingyue Yang
- Department of Gastroenterology, Affiliated Hospital of Zunyi Medical University, Zunyi, Guizhou 563003, P.R. China
| | - Shun Yao
- Department of Gastroenterology, Affiliated Hospital of Zunyi Medical University, Zunyi, Guizhou 563003, P.R. China
| | - Jiaxing An
- Department of Gastroenterology, Affiliated Hospital of Zunyi Medical University, Zunyi, Guizhou 563003, P.R. China
| | - Hai Jin
- Department of Gastroenterology, Affiliated Hospital of Zunyi Medical University, Zunyi, Guizhou 563003, P.R. China
| | - Hui Wang
- Department of Gastroenterology, Affiliated Hospital of Zunyi Medical University, Zunyi, Guizhou 563003, P.R. China
| | - Biguang Tuo
- Department of Gastroenterology, Affiliated Hospital of Zunyi Medical University, Zunyi, Guizhou 563003, P.R. China
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Rottet S, Förster B, Hee WY, Rourke LM, Price GD, Long BM. Engineered Accumulation of Bicarbonate in Plant Chloroplasts: Known Knowns and Known Unknowns. FRONTIERS IN PLANT SCIENCE 2021; 12:727118. [PMID: 34531888 PMCID: PMC8438413 DOI: 10.3389/fpls.2021.727118] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/18/2021] [Accepted: 08/06/2021] [Indexed: 05/10/2023]
Abstract
Heterologous synthesis of a biophysical CO2-concentrating mechanism (CCM) in plant chloroplasts offers significant potential to improve the photosynthetic efficiency of C3 plants and could translate into substantial increases in crop yield. In organisms utilizing a biophysical CCM, this mechanism efficiently surrounds a high turnover rate Rubisco with elevated CO2 concentrations to maximize carboxylation rates. A critical feature of both native biophysical CCMs and one engineered into a C3 plant chloroplast is functional bicarbonate (HCO3 -) transporters and vectorial CO2-to-HCO3 - converters. Engineering strategies aim to locate these transporters and conversion systems to the C3 chloroplast, enabling elevation of HCO3 - concentrations within the chloroplast stroma. Several CCM components have been identified in proteobacteria, cyanobacteria, and microalgae as likely candidates for this approach, yet their successful functional expression in C3 plant chloroplasts remains elusive. Here, we discuss the challenges in expressing and regulating functional HCO3 - transporter, and CO2-to-HCO3 - converter candidates in chloroplast membranes as an essential step in engineering a biophysical CCM within plant chloroplasts. We highlight the broad technical and physiological concerns which must be considered in proposed engineering strategies, and present our current status of both knowledge and knowledge-gaps which will affect successful engineering outcomes.
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Affiliation(s)
- Sarah Rottet
- Realizing Increased Photosynthetic Efficiency (RIPE), The Australian National University, Canberra, ACT, Australia
| | - Britta Förster
- Australian Research Council Centre of Excellence for Translational Photosynthesis, Research School of Biology, The Australian National University, Canberra, ACT, Australia
| | - Wei Yih Hee
- Realizing Increased Photosynthetic Efficiency (RIPE), The Australian National University, Canberra, ACT, Australia
| | - Loraine M. Rourke
- Realizing Increased Photosynthetic Efficiency (RIPE), The Australian National University, Canberra, ACT, Australia
| | - G. Dean Price
- Realizing Increased Photosynthetic Efficiency (RIPE), The Australian National University, Canberra, ACT, Australia
- Australian Research Council Centre of Excellence for Translational Photosynthesis, Research School of Biology, The Australian National University, Canberra, ACT, Australia
| | - Benedict M. Long
- Realizing Increased Photosynthetic Efficiency (RIPE), The Australian National University, Canberra, ACT, Australia
- Australian Research Council Centre of Excellence for Translational Photosynthesis, Research School of Biology, The Australian National University, Canberra, ACT, Australia
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6
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Horiguchi G, Matsumoto K, Nemoto K, Inokuchi M, Hirotsu N. Transition From Proto-Kranz-Type Photosynthesis to HCO 3 - Use Photosynthesis in the Amphibious Plant Hygrophila polysperma. FRONTIERS IN PLANT SCIENCE 2021; 12:675507. [PMID: 34220895 PMCID: PMC8242947 DOI: 10.3389/fpls.2021.675507] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 03/03/2021] [Accepted: 04/26/2021] [Indexed: 06/13/2023]
Abstract
Hygrophila polysperma is a heterophyllous amphibious plant. The growth of H. polysperma in submerged conditions is challenging due to the low CO2 environment, increased resistance to gas diffusion, and bicarbonate ion (HCO3 -) being the dominant dissolved inorganic carbon source. The submerged leaves of H. polysperma have significantly higher rates of underwater photosynthesis compared with the terrestrial leaves. 4,4'-Diisothiocyanatostilbene-2,2'-disulfonate (DIDS), an anion exchanger protein inhibitor, and ethoxyzolamide (EZ), an inhibitor of internal carbonic anhydrase, repressed underwater photosynthesis by the submerged leaves. These results suggested that H. polysperma acclimates to the submerged condition by using HCO3 - for photosynthesis. H. polysperma transports HCO3 - into the leaf by a DIDS-sensitive HCO3 - transporter and converted to CO2 by carbonic anhydrase. Additionally, proteome analysis revealed that submerged leaves accumulated fewer proteins associated with C4 photosynthesis compared with terrestrial leaves. This finding suggested that H. polysperma is capable of C4 and C3 photosynthesis in the terrestrial and submerged leaves, respectively. The ratio of phosphoenol pyruvate carboxylase to ribulose 1,5-bisphosphate carboxylase/oxygenase (Rubisco) in the submerged leaves was less than that in the terrestrial leaves. Upon anatomical observation, the terrestrial leaves exhibited a phenotype similar to the Kranz anatomy found among C4 plants; however, chloroplasts in the bundle sheath cells were not located adjacent to the vascular bundles, and the typical Kranz anatomy was absent in submerged leaves. These results suggest that H. polysperma performs proto-Kranz type photosynthesis in a terrestrial environment and shifts from a proto-Kranz type in terrestrial leaves to a HCO3 - use photosynthesis in the submerged environments.
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Affiliation(s)
- Genki Horiguchi
- Graduate School of Life Sciences, Toyo University, Gunma, Japan
| | | | - Kyosuke Nemoto
- Graduate School of Life Sciences, Toyo University, Gunma, Japan
| | - Mayu Inokuchi
- Faculty of Life Sciences, Toyo University, Gunma, Japan
- Department of Aquatic Bioscience, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Tokyo, Japan
| | - Naoki Hirotsu
- Graduate School of Life Sciences, Toyo University, Gunma, Japan
- Faculty of Life Sciences, Toyo University, Gunma, Japan
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7
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Le Gouic B, Marec H, Pruvost J, Cornet J. Investigation of growth limitation by CO2 mass transfer and inorganic carbon source for the microalga Chlorella vulgaris in a dedicated photobioreactor. Chem Eng Sci 2021. [DOI: 10.1016/j.ces.2020.116388] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
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8
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Chi X, Jin X, Chen Y, Lu X, Tu X, Li X, Zhang Y, Lei J, Huang J, Huang Z, Zhou Q, Pan X. Structural insights into the gating mechanism of human SLC26A9 mediated by its C-terminal sequence. Cell Discov 2020; 6:55. [PMID: 32818062 PMCID: PMC7417587 DOI: 10.1038/s41421-020-00193-7] [Citation(s) in RCA: 40] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2020] [Accepted: 07/07/2020] [Indexed: 11/25/2022] Open
Abstract
The human SLC26 transporter family exhibits various transport characteristics, and family member SLC26A9 performs multiple roles, including acting as Cl-/HCO3- exchangers, Cl- channels, and Na+ transporters. Some mutations of SLC26A9 are correlated with abnormalities in respiration and digestion systems. As a potential target colocalizing with CFTR in cystic fibrosis patients, SLC26A9 is of great value in drug development. Here, we present a cryo-EM structure of the human SLC26A9 dimer at 2.6 Å resolution. A segment at the C-terminal end is bound to the entry of the intracellular vestibule of the putative transport pathway, which has been proven by electrophysiological experiments to be a gating modulator. Multiple chloride and sodium ions are resolved in the high-resolution structure, identifying novel ion-binding pockets for the first time. Together, our structure takes important steps in elucidating the structural features and regulatory mechanism of SLC26A9, with potential significance in the treatment of cystic fibrosis.
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Affiliation(s)
- Ximin Chi
- Key Laboratory of Structural Biology of Zhejiang Province, Institute of Biology, Westlake Institute for Advanced Study, School of Life Sciences, Westlake University, 18 Shilongshan Road, Hangzhou, Zhejiang 310024 China
| | - Xueqin Jin
- State Key Laboratory of Membrane Biology, Beijing Advanced Innovation Center for Structural Biology, Tsinghua-Peking Joint Center for Life Sciences, School of Life Sciences, Tsinghua University, Beijing, 100084 China
| | - Yun Chen
- Key Laboratory of Structural Biology of Zhejiang Province, Institute of Biology, Westlake Institute for Advanced Study, School of Life Sciences, Westlake University, 18 Shilongshan Road, Hangzhou, Zhejiang 310024 China
| | - Xiaoli Lu
- Key Laboratory of Structural Biology of Zhejiang Province, Institute of Biology, Westlake Institute for Advanced Study, School of Life Sciences, Westlake University, 18 Shilongshan Road, Hangzhou, Zhejiang 310024 China
| | - Xinyu Tu
- State Key Laboratory of Natural and Biomimetic Drugs, Department of Molecular and Cellular Pharmacology, School of Pharmaceutical Sciences, Peking University, Beijing, 100191 China
| | - Xiaorong Li
- Key Laboratory of Structural Biology of Zhejiang Province, Institute of Biology, Westlake Institute for Advanced Study, School of Life Sciences, Westlake University, 18 Shilongshan Road, Hangzhou, Zhejiang 310024 China
| | - Yuanyuan Zhang
- Key Laboratory of Structural Biology of Zhejiang Province, Institute of Biology, Westlake Institute for Advanced Study, School of Life Sciences, Westlake University, 18 Shilongshan Road, Hangzhou, Zhejiang 310024 China
| | - Jianlin Lei
- Technology Center for Protein Sciences, Ministry of Education Key Laboratory of Protein Sciences, School of Life Sciences, Tsinghua University, Beijing, 100084 China
| | - Jing Huang
- Key Laboratory of Structural Biology of Zhejiang Province, Institute of Biology, Westlake Institute for Advanced Study, School of Life Sciences, Westlake University, 18 Shilongshan Road, Hangzhou, Zhejiang 310024 China
| | - Zhuo Huang
- State Key Laboratory of Natural and Biomimetic Drugs, Department of Molecular and Cellular Pharmacology, School of Pharmaceutical Sciences, Peking University, Beijing, 100191 China
- Key Laboratory for Neuroscience, Ministry of Education/National Health and Family Planning Commission, Peking University, Beijing, 100191 China
| | - Qiang Zhou
- Key Laboratory of Structural Biology of Zhejiang Province, Institute of Biology, Westlake Institute for Advanced Study, School of Life Sciences, Westlake University, 18 Shilongshan Road, Hangzhou, Zhejiang 310024 China
| | - Xiaojing Pan
- State Key Laboratory of Membrane Biology, Beijing Advanced Innovation Center for Structural Biology, Tsinghua-Peking Joint Center for Life Sciences, School of Life Sciences, Tsinghua University, Beijing, 100084 China
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9
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Bu G, Parrish S, Gleason PR, Nielsen DR, Nannenga BL. Heterologous expression and purification of the bicarbonate transporter BicA from Synechocystis sp. PCC 6803. Protein Expr Purif 2020; 175:105716. [PMID: 32738437 DOI: 10.1016/j.pep.2020.105716] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2020] [Revised: 06/25/2020] [Accepted: 07/22/2020] [Indexed: 11/18/2022]
Abstract
The high-flux/low-affinity cyanobacterial bicarbonate transporter BicA is a member of sulfate permease/solute carrier 26 (SulP/SLC26) family and plays a major role in cyanobacterial inorganic carbon uptake. In order to study this important membrane protein, robust platforms for over-expression and protocols for purification are required. In this work we have optimized the expression and purification of BicA from strain Synechocystis sp. PCC 6803 (BicA6803) in Escherichia coli. It was determined that expression with C43 (DE3) Rosetta2 at 37 °C produced the highest levels of over-expressed BicA6803 relative to other strains screened, and membrane solubilization with n-dodecyl-β-d-maltopyranoside facilitated the purification of high levels of stable and homogenous BicA6803. Using these expression and purification strategies, the final yields of purified BicA were 6.5 ± 1.0 mg per liter of culture.
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Affiliation(s)
- Guanhong Bu
- Chemical Engineering, School for Engineering of Matter, Transport and Energy, Arizona State University, Tempe, AZ, 85287, USA; Center for Applied Structural Discovery, The Biodesign Institute, Arizona State University, Tempe, AZ, 85287, USA
| | - Sydney Parrish
- Chemical Engineering, School for Engineering of Matter, Transport and Energy, Arizona State University, Tempe, AZ, 85287, USA
| | - Patrick R Gleason
- School of Molecular Sciences, Arizona State University, Tempe, AZ, 85287, USA; Center for Molecular Design and Biomimetics, The Biodesign Institute, Arizona State University, Tempe, AZ, 85278, USA
| | - David R Nielsen
- Chemical Engineering, School for Engineering of Matter, Transport and Energy, Arizona State University, Tempe, AZ, 85287, USA
| | - Brent L Nannenga
- Chemical Engineering, School for Engineering of Matter, Transport and Energy, Arizona State University, Tempe, AZ, 85287, USA; Center for Applied Structural Discovery, The Biodesign Institute, Arizona State University, Tempe, AZ, 85287, USA.
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10
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Scott KM, Leonard JM, Boden R, Chaput D, Dennison C, Haller E, Harmer TL, Anderson A, Arnold T, Budenstein S, Brown R, Brand J, Byers J, Calarco J, Campbell T, Carter E, Chase M, Cole M, Dwyer D, Grasham J, Hanni C, Hazle A, Johnson C, Johnson R, Kirby B, Lewis K, Neumann B, Nguyen T, Nino Charari J, Morakinyo O, Olsson B, Roundtree S, Skjerve E, Ubaldini A, Whittaker R. Diversity in CO 2-Concentrating Mechanisms among Chemolithoautotrophs from the Genera Hydrogenovibrio, Thiomicrorhabdus, and Thiomicrospira, Ubiquitous in Sulfidic Habitats Worldwide. Appl Environ Microbiol 2019; 85:e02096-18. [PMID: 30446552 PMCID: PMC6344615 DOI: 10.1128/aem.02096-18] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2018] [Accepted: 11/05/2018] [Indexed: 12/30/2022] Open
Abstract
Members of the genera Hydrogenovibrio, Thiomicrospira, and Thiomicrorhabdus fix carbon at hydrothermal vents, coastal sediments, hypersaline lakes, and other sulfidic habitats. The genome sequences of these ubiquitous and prolific chemolithoautotrophs suggest a surprising diversity of mechanisms for the uptake and fixation of dissolved inorganic carbon (DIC); these mechanisms are verified here. Carboxysomes are apparent in the transmission electron micrographs of most of these organisms but are lacking in Thiomicrorhabdus sp. strain Milos-T2 and Thiomicrorhabdus arctica, and the inability of Thiomicrorhabdus sp. strain Milos-T2 to grow under low-DIC conditions is consistent with the absence of carboxysome loci in its genome. For the remaining organisms, genes encoding potential DIC transporters from four evolutionarily distinct families (Tcr_0853 and Tcr_0854, Chr, SbtA, and SulP) are located downstream of carboxysome loci. Transporter genes collocated with carboxysome loci, as well as some homologs located elsewhere on the chromosomes, had elevated transcript levels under low-DIC conditions, as assayed by reverse transcription-quantitative PCR (qRT-PCR). DIC uptake was measureable via silicone oil centrifugation when a representative of each of the four types of transporter was expressed in Escherichia coli The expression of these genes in the carbonic anhydrase-deficient E. coli strain EDCM636 enabled it to grow under low-DIC conditions, a result consistent with DIC transport by these proteins. The results from this study expand the range of DIC transporters within the SbtA and SulP transporter families, verify DIC uptake by transporters encoded by Tcr_0853 and Tcr_0854 and their homologs, and introduce DIC as a potential substrate for transporters from the Chr family.IMPORTANCE Autotrophic organisms take up and fix DIC, introducing carbon into the biological portion of the global carbon cycle. The mechanisms for DIC uptake and fixation by autotrophic Bacteria and Archaea are likely to be diverse but have been well characterized only for "Cyanobacteria" Based on genome sequences, members of the genera Hydrogenovibrio, Thiomicrospira, and Thiomicrorhabdus have a variety of mechanisms for DIC uptake and fixation. We verified that most of these organisms are capable of growing under low-DIC conditions, when they upregulate carboxysome loci and transporter genes collocated with these loci on their chromosomes. When these genes, which fall into four evolutionarily independent families of transporters, are expressed in E. coli, DIC transport is detected. This expansion in known DIC transporters across four families, from organisms from a variety of environments, provides insight into the ecophysiology of autotrophs, as well as a toolkit for engineering microorganisms for carbon-neutral biochemistries of industrial importance.
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Affiliation(s)
- Kathleen M Scott
- Department of Integrative Biology, University of South Florida, Tampa, Florida, USA
| | - Juliana M Leonard
- Department of Integrative Biology, University of South Florida, Tampa, Florida, USA
| | - Rich Boden
- School of Biological and Marine Sciences, University of Plymouth, Plymouth, United Kingdom
- Sustainable Earth Institute, University of Plymouth, Plymouth, United Kingdom
| | - Dale Chaput
- Proteomics and Mass Spectrometry Facility, University of South Florida, Tampa, Florida, USA
| | - Clare Dennison
- Department of Integrative Biology, University of South Florida, Tampa, Florida, USA
| | - Edward Haller
- Department of Integrative Biology, University of South Florida, Tampa, Florida, USA
| | - Tara L Harmer
- Biology Program, Stockton University, Galloway, New Jersey, USA
| | - Abigail Anderson
- Department of Integrative Biology, University of South Florida, Tampa, Florida, USA
| | - Tiffany Arnold
- Department of Integrative Biology, University of South Florida, Tampa, Florida, USA
| | - Samantha Budenstein
- Department of Integrative Biology, University of South Florida, Tampa, Florida, USA
| | - Rikki Brown
- Department of Integrative Biology, University of South Florida, Tampa, Florida, USA
| | - Juan Brand
- Department of Integrative Biology, University of South Florida, Tampa, Florida, USA
| | - Jacob Byers
- Department of Integrative Biology, University of South Florida, Tampa, Florida, USA
| | - Jeanette Calarco
- Department of Integrative Biology, University of South Florida, Tampa, Florida, USA
| | - Timothy Campbell
- Department of Integrative Biology, University of South Florida, Tampa, Florida, USA
| | - Erica Carter
- Department of Integrative Biology, University of South Florida, Tampa, Florida, USA
| | - Max Chase
- Department of Integrative Biology, University of South Florida, Tampa, Florida, USA
| | - Montana Cole
- Department of Integrative Biology, University of South Florida, Tampa, Florida, USA
| | - Deandra Dwyer
- Department of Integrative Biology, University of South Florida, Tampa, Florida, USA
| | - Jonathon Grasham
- Department of Integrative Biology, University of South Florida, Tampa, Florida, USA
| | - Christopher Hanni
- Department of Integrative Biology, University of South Florida, Tampa, Florida, USA
| | - Ashlee Hazle
- Department of Integrative Biology, University of South Florida, Tampa, Florida, USA
| | - Cody Johnson
- Department of Integrative Biology, University of South Florida, Tampa, Florida, USA
| | - Ryan Johnson
- Department of Integrative Biology, University of South Florida, Tampa, Florida, USA
| | - Brandi Kirby
- Department of Integrative Biology, University of South Florida, Tampa, Florida, USA
| | - Katherine Lewis
- Department of Integrative Biology, University of South Florida, Tampa, Florida, USA
| | - Brianna Neumann
- Department of Integrative Biology, University of South Florida, Tampa, Florida, USA
| | - Tracy Nguyen
- Department of Integrative Biology, University of South Florida, Tampa, Florida, USA
| | | | - Ooreoluwa Morakinyo
- Department of Integrative Biology, University of South Florida, Tampa, Florida, USA
| | - Bengt Olsson
- Department of Integrative Biology, University of South Florida, Tampa, Florida, USA
| | - Shanetta Roundtree
- Department of Integrative Biology, University of South Florida, Tampa, Florida, USA
| | - Emily Skjerve
- Department of Integrative Biology, University of South Florida, Tampa, Florida, USA
| | - Ashley Ubaldini
- Department of Integrative Biology, University of South Florida, Tampa, Florida, USA
| | - Robert Whittaker
- Department of Integrative Biology, University of South Florida, Tampa, Florida, USA
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11
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Machingura MC, Bajsa-Hirschel J, Laborde SM, Schwartzenburg JB, Mukherjee B, Mukherjee A, Pollock SV, Förster B, Price GD, Moroney JV. Identification and characterization of a solute carrier, CIA8, involved in inorganic carbon acclimation in Chlamydomonas reinhardtii. JOURNAL OF EXPERIMENTAL BOTANY 2017; 68:3879-3890. [PMID: 28633328 PMCID: PMC5853530 DOI: 10.1093/jxb/erx189] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/27/2017] [Accepted: 05/12/2017] [Indexed: 05/22/2023]
Abstract
The supply of inorganic carbon (Ci) at the site of fixation by Rubisco is a key parameter for efficient CO2 fixation in aquatic organisms including the green alga, Chlamydomonas reinhardtii. Chlamydomonas reinhardtii cells, when grown on limiting CO2, have a CO2-concentrating mechanism (CCM) that functions to concentrate CO2 at the site of Rubisco. Proteins thought to be involved in inorganic carbon uptake have been identified and localized to the plasma membrane or chloroplast envelope. However, current CCM models suggest that additional molecular components are involved in Ci uptake. In this study, the gene Cia8 was identified in an insertional mutagenesis screen and characterized. The protein encoded by Cia8 belongs to the sodium bile acid symporter subfamily. Transcript levels for this gene were significantly up-regulated when the cells were grown on low CO2. The cia8 mutant exhibited reduced growth and reduced affinity for Ci when grown in limiting CO2 conditions. Prediction programs localize this protein to the chloroplast. Ci uptake and the photosynthetic rate, particularly at high external pH, were reduced in the mutant. The results are consistent with the model that CIA8 is involved in Ci uptake in C. reinhardtii.
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Affiliation(s)
- Marylou C Machingura
- Department of Biological Sciences, Louisiana State University, Baton Rouge, LA, USA
| | | | - Susan M Laborde
- Department of Biological Sciences, Louisiana State University, Baton Rouge, LA, USA
| | | | - Bratati Mukherjee
- ARC Centre of Excellence for Translational Photosynthesis, Division of Plant Sciences, Research School of Biology, Australian National University, Canberra ACT, Australia
| | - Ananya Mukherjee
- Department of Biological Sciences, Louisiana State University, Baton Rouge, LA, USA
| | - Steve V Pollock
- Department of Biological Sciences, Louisiana State University, Baton Rouge, LA, USA
| | - Britta Förster
- ARC Centre of Excellence for Translational Photosynthesis, Division of Plant Sciences, Research School of Biology, Australian National University, Canberra ACT, Australia
| | - G Dean Price
- ARC Centre of Excellence for Translational Photosynthesis, Division of Plant Sciences, Research School of Biology, Australian National University, Canberra ACT, Australia
| | - James V Moroney
- Department of Biological Sciences, Louisiana State University, Baton Rouge, LA, USA
- Correspondence:
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12
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Tomar V, Sidhu GK, Nogia P, Mehrotra R, Mehrotra S. Role of habitat and great oxidation event on the occurrence of three multisubunit inorganic carbon-uptake systems in cyanobacteria. J Genet 2016; 95:109-18. [PMID: 27019438 DOI: 10.1007/s12041-015-0606-x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
Abstract
The oxygenase reaction catalyzed by RuBisCO became an issue only after the evolution of the oxygenic photosynthesis in cyanobacteria. Several strategies were developed by autotrophic organisms as an evolutionary response to increase oxygen levels to help RuBisCO maximize its net carboxylation rate. One of the crucial advancements in this context was the development of more efficient inorganic carbon transporters which could help in increasing the influx of inorganic carbon (Ci) at the site of CO₂ fixation.We conducted a survey to find out the genes coding for cyanobacterial Ci transporters in 40 cyanobacterial phyla with respect to transporters present in Gloeobacter violaceous PCC 7421, an early-diverging cyanobacterium. An attempt was also made to correlate the prevalence of the kind of transporter present in the species with its habitat. Basically, two types of cyanobacterial inorganic carbon transporters exist, i.e. bicarbonate transporters and CO₂-uptake systems. The transporters also show variation in context to their structure as some exist as single subunit proteins (BicA and SbtA), while others exist as multisubunit proteins (namely BCT1, NdhI₃ and NdhI₄). The phylogeny and dist ribution of the former have been extensively studied and the present analysis provides an insight into the latter ones. The in silico analysis of the genes under study revealed that their distribution was greatly influenced by the habitat and major environmental changes such as the great oxidation event (GOE) in the course of their evolution.
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Affiliation(s)
- Vandana Tomar
- Department of Biological Sciences, Birla Institute of Technology and Science, Pilani 333 031,
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13
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Srinivasan L, Baars TL, Fendler K, Michel H. Functional characterization of solute carrier (SLC) 26/sulfate permease (SulP) proteins in membrane mimetic systems. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2016; 1858:698-705. [DOI: 10.1016/j.bbamem.2016.01.006] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/15/2015] [Revised: 12/17/2015] [Accepted: 01/12/2016] [Indexed: 11/25/2022]
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14
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Rolland V, Badger MR, Price GD. Redirecting the Cyanobacterial Bicarbonate Transporters BicA and SbtA to the Chloroplast Envelope: Soluble and Membrane Cargos Need Different Chloroplast Targeting Signals in Plants. FRONTIERS IN PLANT SCIENCE 2016; 7:185. [PMID: 26973659 PMCID: PMC4770052 DOI: 10.3389/fpls.2016.00185] [Citation(s) in RCA: 42] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/17/2015] [Accepted: 02/03/2016] [Indexed: 05/18/2023]
Abstract
Most major crops used for human consumption are C3 plants, which yields are limited by photosynthetic inefficiency. To circumvent this, it has been proposed to implement the cyanobacterial CO2-concentrating mechanism (CCM), principally consisting of bicarbonate transporters and carboxysomes, into plant chloroplasts. As it is currently not possible to recover homoplasmic transplastomic monocots, foreign genes must be introduced in these plants via nuclear transformation. Consequently, it is paramount to ensure that resulting proteins reach the appropriate sub-cellular compartment, which for cyanobacterial transporters BicA and SbtA, is the chloroplast inner-envelope membrane (IEM). At present, targeting signals to redirect large transmembrane proteins from non-chloroplastic organisms to plant chloroplast envelopes are unknown. The goal of this study was to identify such signals, using agrobacteria-mediated transient expression and confocal microscopy to determine the sub-cellular localization of ∼37 GFP-tagged chimeras. Initially, fragments of chloroplast proteins known to target soluble cargos to the stroma were tested for their ability to redirect BicA, but they proved ineffective. Next, different N-terminal regions from Arabidopsis IEM transporters were tested. We demonstrated that the N-terminus of AtHP59, AtPLGG1 or AtNTT1 (92-115 amino acids), containing a cleavable chloroplast transit peptide (cTP) and a membrane protein leader (MPL), was sufficient to redirect BicA or SbtA to the chloroplast envelope. This constitutes the first evidence that nuclear-encoded transmembrane proteins from non-chloroplastic organisms can be targeted to the envelope of plant chloroplasts; a finding which represents an important advance in chloroplast engineering by opening up the door to further manipulation of the chloroplastic envelope.
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15
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Yang ZN, Li XM, Umar A, Fan WH, Wang Y. Insight into calcification of Synechocystis sp. enhanced by extracellular carbonic anhydrase. RSC Adv 2016. [DOI: 10.1039/c5ra26159g] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
The mechanism of cyanobacterial calcification was proved to be related to extracellular carbonic anhydrase, which enhanced CaCO3 precipitation through facilitating proton consumption during transformation of bicarbonate to carbon dioxide.
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Affiliation(s)
- Zhen-Ni Yang
- Key Laboratory of Bio-inspired Smart Interfacial Science and Technology of Ministry of Education
- School of Chemistry and Environment
- Beihang University
- Beijing
- P. R. China
| | - Xiao-Min Li
- Key Laboratory of Bio-inspired Smart Interfacial Science and Technology of Ministry of Education
- School of Chemistry and Environment
- Beihang University
- Beijing
- P. R. China
| | - Ahmad Umar
- Department of Chemistry
- College of Science and Arts and Promising Centre for Sensors and Electronic Devices (PCSED)
- Najran University
- Najran 11001
- Kingdom of Saudi Arabia
| | - Wen-Hong Fan
- Key Laboratory of Bio-inspired Smart Interfacial Science and Technology of Ministry of Education
- School of Chemistry and Environment
- Beihang University
- Beijing
- P. R. China
| | - Yao Wang
- Key Laboratory of Bio-inspired Smart Interfacial Science and Technology of Ministry of Education
- School of Chemistry and Environment
- Beihang University
- Beijing
- P. R. China
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16
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Gaudana SB, Zarzycki J, Moparthi VK, Kerfeld CA. Bioinformatic analysis of the distribution of inorganic carbon transporters and prospective targets for bioengineering to increase Ci uptake by cyanobacteria. PHOTOSYNTHESIS RESEARCH 2015; 126:99-109. [PMID: 25399051 DOI: 10.1007/s11120-014-0059-8] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/20/2014] [Accepted: 11/07/2014] [Indexed: 06/04/2023]
Abstract
Cyanobacteria have evolved a carbon-concentrating mechanism (CCM) which has enabled them to inhabit diverse environments encompassing a range of inorganic carbon (Ci: [Formula: see text] and CO2) concentrations. Several uptake systems facilitate inorganic carbon accumulation in the cell, which can in turn be fixed by ribulose 1,5-bisphosphate carboxylase/oxygenase. Here we survey the distribution of genes encoding known Ci uptake systems in cyanobacterial genomes and, using a pfam- and gene context-based approach, identify in the marine (alpha) cyanobacteria a heretofore unrecognized number of putative counterparts to the well-known Ci transporters of beta cyanobacteria. In addition, our analysis shows that there is a huge repertoire of transport systems in cyanobacteria of unknown function, many with homology to characterized Ci transporters. These can be viewed as prospective targets for conversion into ancillary Ci transporters through bioengineering. Increasing intracellular Ci concentration coupled with efforts to increase carbon fixation will be beneficial for the downstream conversion of fixed carbon into value-added products including biofuels. In addition to CCM transporter homologs, we also survey the occurrence of rhodopsin homologs in cyanobacteria, including bacteriorhodopsin, a class of retinal-binding, light-activated proton pumps. Because they are light driven and because of the apparent ease of altering their ion selectivity, we use this as an example of re-purposing an endogenous transporter for the augmentation of Ci uptake by cyanobacteria and potentially chloroplasts.
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Affiliation(s)
- Sandeep B Gaudana
- DOE Plant Research Laboratories, Department of Biochemistry and Molecular Biology, Michigan State University, 612 Wilson Road, East Lansing, MI, 48824, USA
| | - Jan Zarzycki
- DOE Plant Research Laboratories, Department of Biochemistry and Molecular Biology, Michigan State University, 612 Wilson Road, East Lansing, MI, 48824, USA
- Physical Biosciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA, 94720, USA
| | - Vamsi K Moparthi
- Department of Energy Joint Genome Institute, 2800 Mitchell Drive, Walnut Creek, CA, 94598, USA
| | - Cheryl A Kerfeld
- DOE Plant Research Laboratories, Department of Biochemistry and Molecular Biology, Michigan State University, 612 Wilson Road, East Lansing, MI, 48824, USA.
- Physical Biosciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA, 94720, USA.
- Department of Plant and Microbial Biology, University of California, Berkeley, CA, 94720, USA.
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17
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Geertsma ER, Chang YN, Shaik FR, Neldner Y, Pardon E, Steyaert J, Dutzler R. Structure of a prokaryotic fumarate transporter reveals the architecture of the SLC26 family. Nat Struct Mol Biol 2015; 22:803-8. [PMID: 26367249 DOI: 10.1038/nsmb.3091] [Citation(s) in RCA: 122] [Impact Index Per Article: 13.6] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2015] [Accepted: 08/20/2015] [Indexed: 12/18/2022]
Abstract
The SLC26 family of membrane proteins combines a variety of functions within a conserved molecular scaffold. Its members, besides coupled anion transporters and channels, include the motor protein Prestin, which confers electromotility to cochlear outer hair cells. To gain insight into the architecture of this protein family, we characterized the structure and function of SLC26Dg, a facilitator of proton-coupled fumarate symport, from the bacterium Deinococcus geothermalis. Its modular structure combines a transmembrane unit and a cytoplasmic STAS domain. The membrane-inserted domain consists of two intertwined inverted repeats of seven transmembrane segments each and resembles the fold of the unrelated transporter UraA. It shows an inward-facing, ligand-free conformation with a potential substrate-binding site at the interface between two helix termini at the center of the membrane. This structure defines the common framework for the diverse functional behavior of the SLC26 family.
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Affiliation(s)
- Eric R Geertsma
- Department of Biochemistry, University of Zurich, Zurich, Switzerland.,Institute of Biochemistry, Biocenter, Goethe-University Frankfurt, Frankfurt am Main, Germany
| | - Yung-Ning Chang
- Department of Biochemistry, University of Zurich, Zurich, Switzerland.,Institute of Biochemistry, Biocenter, Goethe-University Frankfurt, Frankfurt am Main, Germany
| | - Farooque R Shaik
- Department of Biochemistry, University of Zurich, Zurich, Switzerland
| | - Yvonne Neldner
- Department of Biochemistry, University of Zurich, Zurich, Switzerland
| | - Els Pardon
- Structural Biology Research Center, Vlaams Instituut voor Biotechnologie, Brussels, Belgium.,Structural Biology Brussels, Vrije Universiteit Brussel, Brussels, Belgium
| | - Jan Steyaert
- Structural Biology Research Center, Vlaams Instituut voor Biotechnologie, Brussels, Belgium.,Structural Biology Brussels, Vrije Universiteit Brussel, Brussels, Belgium
| | - Raimund Dutzler
- Department of Biochemistry, University of Zurich, Zurich, Switzerland
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18
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Installing extra bicarbonate transporters in the cyanobacterium Synechocystis sp. PCC6803 enhances biomass production. Metab Eng 2015; 29:76-85. [DOI: 10.1016/j.ymben.2015.03.002] [Citation(s) in RCA: 65] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2014] [Revised: 02/15/2015] [Accepted: 03/02/2015] [Indexed: 11/18/2022]
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19
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Abstract
The Slc26 proteins are a ubiquitous superfamily of anion transporters conserved from bacteria to humans, among which four have been identified as human disease genes. Our functional knowledge of this protein family has increased but limited structural information is available. These proteins contain a transmembrane (TM) domain and a C-terminal cytoplasmic sulfate transporter and anti-sigma factor (STAS) domain. In a fundamental step towards understanding the structure/function relationships within the family we have used small-angle neutron scattering (SANS) on two distantly related bacterial homologues to show that there is a common, dimeric and structural architecture among Slc26A transporters. Pulsed electron-electron double resonance (PELDOR) spectroscopy supports the dimeric SANS-derived model. Using chimaeric/truncated proteins we have determined the domain organization: the STAS domains project away from the TM core and are essential for protein stability. We use the SANS-generated envelopes to assess a homology model of the TM core.
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20
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Price GD, Howitt SM. Topology mapping to characterize cyanobacterial bicarbonate transporters: BicA (SulP/SLC26 family) and SbtA. Mol Membr Biol 2014; 31:177-82. [DOI: 10.3109/09687688.2014.953222] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
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21
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Pengelly JJL, Förster B, von Caemmerer S, Badger MR, Price GD, Whitney SM. Transplastomic integration of a cyanobacterial bicarbonate transporter into tobacco chloroplasts. JOURNAL OF EXPERIMENTAL BOTANY 2014; 65:3071-80. [PMID: 24965541 PMCID: PMC4071830 DOI: 10.1093/jxb/eru156] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/18/2023]
Abstract
Improving global yields of agricultural crops is a complex challenge with evidence indicating benefits in productivity are achieved by enhancing photosynthetic carbon assimilation. Towards improving rates of CO2 capture within leaf chloroplasts, this study shows the versatility of plastome transformation for expressing the Synechococcus PCC7002 BicA bicarbonate transporter within tobacco plastids. Fractionation of chloroplast membranes from transplastomic tob(BicA) lines showed that ~75% of the BicA localized to the thylakoid membranes and ~25% to the chloroplast envelope. BicA levels were highest in young emerging tob(BicA) leaves (0.12 μmol m(-2), ≈7mg m(-2)) accounting for ~0.1% (w/w) of the leaf protein. In these leaves, the molar amount of BicA was 16-fold lower than the abundant thylakoid photosystem II D1 protein (~1.9 μmol m(-2)) which was comparable to the 9:1 molar ratio of D1:BicA measured in air-grown Synechococcus PCC7002 cells. The BicA produced had no discernible effect on chloroplast ultrastructure, photosynthetic CO2-assimilation rates, carbon isotope discrimination, or growth of the tob(BicA) plants, implying that the bicarbonate transporter had little or no activity. These findings demonstrate the utility of plastome transformation for targeting bicarbonate transporter proteins into the chloroplast membranes without impeding growth or plastid ultrastructure. This study establishes the span of experimental measurements required to verify heterologous bicarbonate transporter function and location in chloroplasts and underscores the need for more detailed understanding of BicA structure and function to identify solutions for enabling its activation and operation in leaf chloroplasts.
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Affiliation(s)
- J J L Pengelly
- Plant Science Division, Research School of Biology, The Australian National University, Canberra, ACT 0200, Australia
| | - B Förster
- Plant Science Division, Research School of Biology, The Australian National University, Canberra, ACT 0200, Australia
| | - S von Caemmerer
- Plant Science Division, Research School of Biology, The Australian National University, Canberra, ACT 0200, Australia
| | - M R Badger
- Plant Science Division, Research School of Biology, The Australian National University, Canberra, ACT 0200, Australia
| | - G D Price
- Plant Science Division, Research School of Biology, The Australian National University, Canberra, ACT 0200, Australia
| | - S M Whitney
- Plant Science Division, Research School of Biology, The Australian National University, Canberra, ACT 0200, Australia
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22
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Li J, Xia F, Reithmeier RAF. N-glycosylation and topology of the human SLC26 family of anion transport membrane proteins. Am J Physiol Cell Physiol 2014; 306:C943-60. [PMID: 24647542 DOI: 10.1152/ajpcell.00030.2014] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The human solute carrier (SLC26) family of anion transporters consists of 10 members (SLCA1-11, SLCA10 being a pseudogene) that encode membrane proteins containing ~12 transmembrane (TM) segments with putative N-glycosylation sites (-NXS/T-) in extracellular loops and a COOH-terminal cytosolic STAS domain. All 10 members of the human SLC26 family, FLAG-tagged at the NH2 terminus, were transiently expressed in HEK-293 cells. While most proteins were observed to contain both high-mannose and complex oligosaccharides, SLC26A2 was mainly in the complex form, SLC26A4 in the high-mannose form, and SLC26A8 was not N-glycosylated. Mutation of the putative N-glycosylation sites showed that most members contain multiple N-glycosylation sites in the second extracytosolic (EC) loop, except SLC26A11, which was N-glycosylated in EC loop 4. Immunofluorescence staining of permeabilized cells localized the proteins to the plasma membrane and the endoplasmic reticulum, with SLC26A2 highly localized to the plasma membrane. N-glycosylation was not a necessary requirement for cell surface expression as the localization of nonglycosylated proteins was similar to their wild-type counterparts, although a lower level of cell-surface biotinylation was observed. No immunostaining of intact cells was observed for any SLC26 members, demonstrating that the NH2-terminal FLAG tag was located in the cytosol. Topological models of the SLC26 proteins that contain an even number of transmembrane segments with both the NH2 and COOH termini located in the cytosol and utilized N-glycosylation sites defining the positions of two EC loops are presented.
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Affiliation(s)
- Jing Li
- Department of Biochemistry, University of Toronto, Toronto, Ontario, Canada
| | - Fan Xia
- Department of Biochemistry, University of Toronto, Toronto, Ontario, Canada
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23
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Sandrini G, Matthijs HCP, Verspagen JMH, Muyzer G, Huisman J. Genetic diversity of inorganic carbon uptake systems causes variation in CO2 response of the cyanobacterium Microcystis. THE ISME JOURNAL 2014; 8:589-600. [PMID: 24132080 PMCID: PMC3930318 DOI: 10.1038/ismej.2013.179] [Citation(s) in RCA: 71] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/12/2013] [Revised: 09/10/2013] [Accepted: 09/11/2013] [Indexed: 11/09/2022]
Abstract
Rising CO2 levels may act as an important selective factor on the CO2-concentrating mechanism (CCM) of cyanobacteria. We investigated genetic diversity in the CCM of Microcystis aeruginosa, a species producing harmful cyanobacterial blooms in many lakes worldwide. All 20 investigated Microcystis strains contained complete genes for two CO2 uptake systems, the ATP-dependent bicarbonate uptake system BCT1 and several carbonic anhydrases (CAs). However, 12 strains lacked either the high-flux bicarbonate transporter BicA or the high-affinity bicarbonate transporter SbtA. Both genes, bicA and sbtA, were located on the same operon, and the expression of this operon is most likely regulated by an additional LysR-type transcriptional regulator (CcmR2). Strains with only a small bicA fragment clustered together in the phylogenetic tree of sbtAB, and the bicA fragments were similar in strains isolated from different continents. This indicates that a common ancestor may first have lost most of its bicA gene and subsequently spread over the world. Growth experiments showed that strains with sbtA performed better at low inorganic carbon (Ci) conditions, whereas strains with bicA performed better at high Ci conditions. This offers an alternative explanation of previous competition experiments, as our results reveal that the competition at low CO2 levels was won by a specialist with only sbtA, whereas a generalist with both bicA and sbtA won at high CO2 levels. Hence, genetic and phenotypic variation in Ci uptake systems provide Microcystis with the potential for microevolutionary adaptation to changing CO2 conditions, with a selective advantage for bicA-containing strains in a high-CO2 world.
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Affiliation(s)
- Giovanni Sandrini
- Department of Aquatic Microbiology, Institute for Biodiversity and Ecosystem Dynamics, University of Amsterdam, Amsterdam, The Netherlands
| | - Hans C P Matthijs
- Department of Aquatic Microbiology, Institute for Biodiversity and Ecosystem Dynamics, University of Amsterdam, Amsterdam, The Netherlands
| | - Jolanda M H Verspagen
- Department of Aquatic Microbiology, Institute for Biodiversity and Ecosystem Dynamics, University of Amsterdam, Amsterdam, The Netherlands
| | - Gerard Muyzer
- Department of Aquatic Microbiology, Institute for Biodiversity and Ecosystem Dynamics, University of Amsterdam, Amsterdam, The Netherlands
| | - Jef Huisman
- Department of Aquatic Microbiology, Institute for Biodiversity and Ecosystem Dynamics, University of Amsterdam, Amsterdam, The Netherlands.
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Cordat E, Reithmeier RA. Structure, Function, and Trafficking of SLC4 and SLC26 Anion Transporters. CURRENT TOPICS IN MEMBRANES 2014; 73:1-67. [DOI: 10.1016/b978-0-12-800223-0.00001-3] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
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Alper SL, Sharma AK. The SLC26 gene family of anion transporters and channels. Mol Aspects Med 2013; 34:494-515. [PMID: 23506885 DOI: 10.1016/j.mam.2012.07.009] [Citation(s) in RCA: 259] [Impact Index Per Article: 23.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2012] [Accepted: 06/21/2012] [Indexed: 02/08/2023]
Abstract
The phylogenetically ancient SLC26 gene family encodes multifunctional anion exchangers and anion channels transporting a broad range of substrates, including Cl(-), HCO3(-), sulfate, oxalate, I(-), and formate. SLC26 polypeptides are characterized by N-terminal cytoplasmic domains, 10-14 hydrophobic transmembrane spans, and C-terminal cytoplasmic STAS domains, and appear to be homo-oligomeric. SLC26-related SulP proteins of marine bacteria likely transport HCO3(-) as part of oceanic carbon fixation. SulP genes present in antibiotic operons may provide sulfate for antibiotic biosynthetic pathways. SLC26-related Sultr proteins transport sulfate in unicellular eukaryotes and in plants. Mutations in three human SLC26 genes are associated with congenital or early onset Mendelian diseases: chondrodysplasias for SLC26A2, chloride diarrhea for SLC26A3, and deafness with enlargement of the vestibular aqueduct for SLC26A4. Additional disease phenotypes evident only in mouse knockout models include oxalate urolithiasis for Slc26a6 and Slc26a1, non-syndromic deafness for Slc26a5, gastric hypochlorhydria for Slc26a7 and Slc26a9, distal renal tubular acidosis for Slc26a7, and male infertility for Slc26a8. STAS domains are required for cell surface expression of SLC26 proteins, and contribute to regulation of the cystic fibrosis transmembrane regulator in complex, cell- and tissue-specific ways. The protein interactomes of SLC26 polypeptides are under active investigation.
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Affiliation(s)
- Seth L Alper
- Renal Division and Division of Molecular and Vascular Medicine, Beth Israel Deaconess Medical Center, Boston, MA 02215, USA.
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Rae BD, Long BM, Badger MR, Price GD. Functions, compositions, and evolution of the two types of carboxysomes: polyhedral microcompartments that facilitate CO2 fixation in cyanobacteria and some proteobacteria. Microbiol Mol Biol Rev 2013; 77:357-79. [PMID: 24006469 PMCID: PMC3811607 DOI: 10.1128/mmbr.00061-12] [Citation(s) in RCA: 242] [Impact Index Per Article: 22.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Cyanobacteria are the globally dominant photoautotrophic lineage. Their success is dependent on a set of adaptations collectively termed the CO2-concentrating mechanism (CCM). The purpose of the CCM is to support effective CO2 fixation by enhancing the chemical conditions in the vicinity of the primary CO2-fixing enzyme, D-ribulose 1,5-bisphosphate carboxylase/oxygenase (RubisCO), to promote the carboxylase reaction and suppress the oxygenase reaction. In cyanobacteria and some proteobacteria, this is achieved by encapsulation of RubisCO within carboxysomes, which are examples of a group of proteinaceous bodies called bacterial microcompartments. Carboxysomes encapsulate the CO2-fixing enzyme within the selectively permeable protein shell and simultaneously encapsulate a carbonic anhydrase enzyme for CO2 supply from a cytoplasmic bicarbonate pool. These bodies appear to have arisen twice and undergone a process of convergent evolution. While the gross structures of all known carboxysomes are ostensibly very similar, with shared gross features such as a selectively permeable shell layer, each type of carboxysome encapsulates a phyletically distinct form of RubisCO enzyme. Furthermore, the specific proteins forming structures such as the protein shell or the inner RubisCO matrix are not identical between carboxysome types. Each type has evolutionarily distinct forms of the same proteins, as well as proteins that are entirely unrelated to one another. In light of recent developments in the study of carboxysome structure and function, we present this review to summarize the knowledge of the structure and function of both types of carboxysome. We also endeavor to cast light on differing evolutionary trajectories which may have led to the differences observed in extant carboxysomes.
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Affiliation(s)
- Benjamin D Rae
- Division of Plant Science, Research School of Biology, The Australian National University, Canberra, ACT, Australia
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Price GD, Pengelly JJL, Forster B, Du J, Whitney SM, von Caemmerer S, Badger MR, Howitt SM, Evans JR. The cyanobacterial CCM as a source of genes for improving photosynthetic CO2 fixation in crop species. JOURNAL OF EXPERIMENTAL BOTANY 2013; 64:753-68. [PMID: 23028015 DOI: 10.1093/jxb/ers257] [Citation(s) in RCA: 126] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
Crop yields need to nearly double over the next 35 years to keep pace with projected population growth. Improving photosynthesis, via a range of genetic engineering strategies, has been identified as a promising target for crop improvement with regard to increased photosynthetic yield and better water-use efficiency (WUE). One approach is based on integrating components of the highly efficient CO(2)-concentrating mechanism (CCM) present in cyanobacteria (blue-green algae) into the chloroplasts of key C(3) crop plants, particularly wheat and rice. Four progressive phases towards engineering components of the cyanobacterial CCM into C(3) species can be envisaged. The first phase (1a), and simplest, is to consider the transplantation of cyanobacterial bicarbonate transporters to C(3) chloroplasts, by host genomic expression and chloroplast targeting, to raise CO(2) levels in the chloroplast and provide a significant improvement in photosynthetic performance. Mathematical modelling indicates that improvements in photosynthesis as high as 28% could be achieved by introducing both of the single-gene, cyanobacterial bicarbonate transporters, known as BicA and SbtA, into C(3) plant chloroplasts. Part of the first phase (1b) includes the more challenging integration of a functional cyanobacterial carboxysome into the chloroplast by chloroplast genome transformation. The later three phases would be progressively more elaborate, taking longer to engineer other functional components of the cyanobacterial CCM into the chloroplast, and targeting photosynthetic and WUE efficiencies typical of C(4) photosynthesis. These later stages would include the addition of NDH-1-type CO(2) pumps and suppression of carbonic anhydrase and C(3) Rubisco in the chloroplast stroma. We include a score card for assessing the success of physiological modifications gained in phase 1a.
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Affiliation(s)
- G Dean Price
- Molecular Plant Physiology Cluster, Research School of Biology, Australian National University, Canberra, Australian Capital Territory 0200, Australia.
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Karinou E, Compton ELR, Morel M, Javelle A. The Escherichia coli SLC26 homologue YchM (DauA) is a C(4)-dicarboxylic acid transporter. Mol Microbiol 2012; 87:623-40. [PMID: 23278959 DOI: 10.1111/mmi.12120] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 12/03/2012] [Indexed: 01/05/2023]
Abstract
The SLC26/SulP (solute carrier/sulphate transporter) proteins are a ubiquitous superfamily of secondary anion transporters. Prior studies have focused almost exclusively on eukaryotic members and bacterial members are frequently classified as sulphate transporters based on their homology with SulP proteins from plants and fungi. In this study we have examined the function and physiological role of the Escherichia coli Slc26 homologue, YchM. We show that there is a clear YchM-dependent growth defect when succinate is used as the sole carbon source. Using an in vivo succinate transport assay, we show that YchM is the sole aerobic succinate transporter active at acidic pH. We demonstrate that YchM can also transport other C(4) -dicarboxylic acids and that its substrate specificity differs from the well-characterized succinate transporter, DctA. Accordingly ychM was re-designated dauA (dicarboxylic acid uptake system A). Finally, our data suggest that DauA is a protein with transport and regulation activities. This is the first report that a SLC26/SulP protein acts as a C(4) -dicarboxylic acid transporter and an unexpected new function for a prokaryotic member of this transporter family.
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Affiliation(s)
- Eleni Karinou
- Division of Molecular Microbiology, College of Life Sciences, University of Dundee, Dundee DD1 5EH, UK
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Fong P. CFTR-SLC26 transporter interactions in epithelia. Biophys Rev 2012; 4:107-116. [PMID: 22685498 PMCID: PMC3369697 DOI: 10.1007/s12551-012-0068-9] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2011] [Accepted: 01/23/2012] [Indexed: 12/18/2022] Open
Abstract
Transport mechanisms that mediate the movements of anions must be coordinated tightly in order to respond appropriately to physiological stimuli. This process is of paramount importance in the function of diverse epithelial tissues of the body, such as, for example, the exocrine pancreatic duct and the airway epithelia. Disruption of any of the finely tuned components underlying the transport of anions such as Cl(-), HCO(3) (-), SCN(-), and I(-) may contribute to a plethora of disease conditions. In many anion-secreting epithelia, the interactions between the cystic fibrosis transmembrane conductance regulator (CFTR) and solute carrier family 26 (SLC26) transporters determine the final exit of anions across the apical membrane and into the luminal compartment. The molecular identification of CFTR and many SLC26 members has enabled the acquisition of progressively more detailed structural information about these transport molecules. Studies employing a vast array of increasingly sophisticated approaches have culminated in a current working model which places these key players within an interactive complex, thereby setting the stage for future work.
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Affiliation(s)
- Peying Fong
- Department of Anatomy and Physiology, Kansas State University College of Veterinary Medicine, 1600 Denison Avenue, Manhattan, KS 66506 USA
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Sharma AK, Ye L, Alper SL, Rigby AC. Guanine nucleotides differentially modulate backbone dynamics of the STAS domain of the SulP/SLC26 transport protein Rv1739c of Mycobacterium tuberculosis. FEBS J 2011; 279:420-36. [PMID: 22118659 DOI: 10.1111/j.1742-4658.2011.08435.x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Enzymatic catalysis and protein signaling are dynamic processes that involve local and/or global conformational changes occurring across a broad range of time scales. (1) H-(15) N relaxation NMR provides a comprehensive understanding of protein backbone dynamics both in the apo (unliganded) and ligand-bound conformations, enabling both fast and slow internal motions of individual amino acid residues to be observed. We recently reported the structure and nucleotide binding properties of the sulfate transporter and anti-sigma factor antagonist (STAS) domain of Rv1739c, a SulP anion transporter protein of Mycobacterium tuberculosis. In the present study, we report (1) H-(15) N NMR backbone dynamics measurements [longitudinal (T(1) ), transverse (T(2) ) and steady-state ({(1) H}-(15) N) heteronuclear NOE] of the Rv1739c STAS domain, in the absence and presence of saturating concentrations of GTP and GDP. Analysis of measured relaxation data and estimated dynamic parameters indicated distinct features differentiating the binding of GTP and GDP to Rv1739c STAS. The 9.55 ns overall rotational correlation time of Rv1739c STAS increased to 10.48 ns in the presence of GTP, and to 13.25 ns in the presence of GDP, indicating significant nucleotide-induced conformational changes. These conformational changes were accompanied by slow time scale (μs to ms) motions in discrete regions of the protein, as reflected by guanine nucleotide-induced changes in relaxation parameters. The observed nucleotide-specific alterations in the relaxation properties of individual STAS residues reflect an increased molecular anisotropy and/or the emergence of conformational equilibria governing functional properties of the STAS domain.
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Affiliation(s)
- Alok K Sharma
- Division of Molecular and Vascular Medicine, Renal Division, and Center for Vascular Biology Research, Department of Medicine, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA, USA.
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Sharma AK, Rigby AC, Alper SL. STAS domain structure and function. Cell Physiol Biochem 2011; 28:407-22. [PMID: 22116355 PMCID: PMC3709189 DOI: 10.1159/000335104] [Citation(s) in RCA: 71] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/28/2011] [Indexed: 12/23/2022] Open
Abstract
Pendrin shares with nearly all SLC26/SulP anion transporters a carboxy-terminal cytoplasmic segment organized around a Sulfate Transporter and Anti-Sigma factor antagonist (STAS) domain. STAS domains of divergent amino acid sequence exhibit a conserved fold of 4 β strands interspersed among 5 α helices. The first STAS domain proteins studied were single-domain anti-sigma factor antagonists (anti-anti-σ). These anti-anti-σ indirectly stimulate bacterial RNA polymerase by inactivating inhibitory anti-σ kinases, liberating σ factors to direct specific transcription of target genes or operons. Some STAS domains are nucleotide-binding phosphoproteins or nucleotidases. Others are interaction/transduction modules within multidomain sensors of light, oxygen and other gasotransmitters, cyclic nucleotides, inositol phosphates, and G proteins. Additional multidomain STAS protein sequences suggest functions in sensing, metabolism, or transport of nutrients such as sugars, amino acids, lipids, anions, vitamins, or hydrocarbons. Still other multidomain STAS polypeptides include histidine and serine/threonine kinase domains and ligand-activated transcription factor domains. SulP/SLC26 STAS domains and adjacent sequences interact with other transporters, cytoskeletal scaffolds, and with enzymes metabolizing transported anion substrates, forming putative metabolons. STAS domains are central to membrane targeting of many SulP/SLC26 anion transporters, and STAS domain mutations are associated with at least three human recessive diseases. This review summarizes STAS domain structure and function.
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Affiliation(s)
- Alok K Sharma
- Molecular and Vascular Medicine Division, Beth Israel Deaconess Medical Center, Department of Medicine, Harvard Medical School, Boston, MA 02215, USA.
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