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Homologs of Phycobilisome Abundance Regulator PsoR Are Widespread across Cyanobacteria. MICROBIOLOGY RESEARCH 2022. [DOI: 10.3390/microbiolres13020014] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
During chromatic acclimation (CA), cyanobacteria undergo shifts in their physiology and metabolism in response to changes in their light environment. Various forms of CA, which involves the tuning of light-harvesting accessory complexes known as phycobilisomes (PBS) in response to distinct wavelengths of light, have been recognized. Recently, a negative regulator of PBS abundance, PsoR, about which little was known, was identified. We used sequence analyses and bioinformatics to predict the role of PsoR in cyanobacteria and PBS regulation and to examine its presence in a diverse range of cyanobacteria. PsoR has sequence similarities to the β-CASP family of proteins involved in DNA and RNA processing. PsoR is a putative nuclease widespread across Cyanobacteria, of which over 700 homologs have been observed. Promoter analysis suggested that psoR is co-transcribed with upstream gene tcpA. Multiple transcription factors involved in global gene regulation and stress responses were predicted to bind to the psoR-tcpA promoter. The predicted protein–protein interactions with PsoR homologs included proteins involved in DNA and RNA metabolism, as well as a phycocyanin-associated protein predicted to interact with PsoR from Fremyella diplosiphon (FdPsoR). The widespread presence of PsoR homologs in Cyanobacteria and their ties to DNA- and RNA-metabolizing proteins indicated a potentially unique role for PsoR in CA and PBS abundance regulation.
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Dagnino-Leone J, Figueroa CP, Castañeda ML, Youlton AD, Vallejos-Almirall A, Agurto-Muñoz A, Pavón Pérez J, Agurto-Muñoz C. Phycobiliproteins: Structural aspects, functional characteristics, and biotechnological perspectives. Comput Struct Biotechnol J 2022; 20:1506-1527. [PMID: 35422968 PMCID: PMC8983314 DOI: 10.1016/j.csbj.2022.02.016] [Citation(s) in RCA: 24] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2021] [Revised: 02/18/2022] [Accepted: 02/19/2022] [Indexed: 12/13/2022] Open
Abstract
Phycobiliproteins (PBPs) are fluorescent proteins of various colors, including fuchsia, purple-blue and cyan, that allow the capture of light energy in auxiliary photosynthetic complexes called phycobilisomes (PBS). PBPs have several highly preserved structural and physicochemical characteristics. In the PBS context, PBPs function is capture luminous energy in the 450–650 nm range and delivers it to photosystems allowing photosynthesis take place. Besides the energy harvesting function, PBPs also have shown to have multiple biological activities, including antioxidant, antibacterial and antitumours, making them an interesting focus for different biotechnological applications in areas like biomedicine, bioenergy and scientific research. Nowadays, the main sources of PBPs are cyanobacteria and micro and macro algae from the phylum Rhodophyta. Due to the diverse biological activities of PBPs, they have attracted the attention of different industries, such as food, biomedical and cosmetics. This is why a large number of patents related to the production, extraction, purification of PBPs and their application as cosmetics, biopharmaceuticals or diagnostic applications have been generated, looking less ecological impact in the natural prairies of macroalgae and less culture time or higher productivity in cyanobacteria to satisfy the markets and applications that require high amounts of these molecules. In this review, we summarize the main structural characteristics of PBPs, their biosynthesys and biotechnological applications. We also address current trends and future perspectives of the PBPs market.
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Affiliation(s)
- Jorge Dagnino-Leone
- Grupo Interdisciplinario de Biotecnología Marina (GIBMAR), Centro de Biotecnología, Universidad de Concepción, Concepción 4030000, Chile
| | - Cristina Pinto Figueroa
- Grupo Interdisciplinario de Biotecnología Marina (GIBMAR), Centro de Biotecnología, Universidad de Concepción, Concepción 4030000, Chile
| | - Mónica Latorre Castañeda
- Grupo Interdisciplinario de Biotecnología Marina (GIBMAR), Centro de Biotecnología, Universidad de Concepción, Concepción 4030000, Chile
| | - Andrea Donoso Youlton
- Grupo Interdisciplinario de Biotecnología Marina (GIBMAR), Centro de Biotecnología, Universidad de Concepción, Concepción 4030000, Chile
| | - Alejandro Vallejos-Almirall
- Grupo Interdisciplinario de Biotecnología Marina (GIBMAR), Centro de Biotecnología, Universidad de Concepción, Concepción 4030000, Chile
| | - Andrés Agurto-Muñoz
- Grupo Interdisciplinario de Biotecnología Marina (GIBMAR), Centro de Biotecnología, Universidad de Concepción, Concepción 4030000, Chile
| | - Jessy Pavón Pérez
- Grupo Interdisciplinario de Biotecnología Marina (GIBMAR), Centro de Biotecnología, Universidad de Concepción, Concepción 4030000, Chile
- Departamento de Ciencia y Tecnología de los Alimentos (CyTA), Facultad de Farmacia, Universidad de Concepción, Concepción 4030000 Chile
| | - Cristian Agurto-Muñoz
- Grupo Interdisciplinario de Biotecnología Marina (GIBMAR), Centro de Biotecnología, Universidad de Concepción, Concepción 4030000, Chile
- Departamento de Ciencia y Tecnología de los Alimentos (CyTA), Facultad de Farmacia, Universidad de Concepción, Concepción 4030000 Chile
- Corresponding author at: Grupo Interdisciplinario de Biotecnología Marina (GIBMAR), Centro de Biotecnología, Universidad de Concepción, Concepción 4030000, Chile.
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Xie M, Li W, Lin H, Wang X, Dong J, Qin S, Zhao F. Difference in light use strategy in red alga between Griffithsia pacifica and Porphyridium purpureum. Sci Rep 2021; 11:14367. [PMID: 34257340 PMCID: PMC8277835 DOI: 10.1038/s41598-021-93696-6] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2021] [Accepted: 06/29/2021] [Indexed: 11/09/2022] Open
Abstract
Phycobilisomes (PBSs) are the largest light-harvesting antenna in red algae, and feature high efficiency and rate of energy transfer even in a dim environment. To understand the influence of light on the energy transfer in PBSs, two red algae Griffithsia pacifica and Porphyridium purpureum living in different light environment were selected for this research. The energy transfer dynamics in PBSs of the two red algae were studied in time-resolved fluorescence spectroscopy in sub-picosecond resolution. The energy transfer pathways and the related transfer rates were uncovered by deconvolution of the fluorescence decay curve. Four time-components, i.e., 8 ps, 94 ps, 970 ps, and 2288 ps were recognized in the energy transfer in PBSs of G. pacifica, and 10 ps, 74 ps, 817 ps and 1292 ps in P. purpureum. In addition, comparison in energy transfer dynamics between the two red algae revealed that the energy transfer was clearly affected by lighting environment. The findings help us to understand the energy transfer mechanisms of red algae for adaptation to a natural low light environment.
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Affiliation(s)
- Mingyuan Xie
- School of Physics, State Key Laboratory of Optoelectronic Materials and Technologies, Sun Yat-Sen University, Guangzhou, 510275, Guangdong, China.,Institute of Advanced Science Facilities, Shenzhen, 518107, Guangdong, China
| | - Wenjun Li
- Key Laboratory of Coastal Biology and Biological Resource Utilization, Yantai Institute of Coastal Zone Research, Chinese Academy of Sciences, Yantai, 264003, Shandong, China
| | - Hanzhi Lin
- Institute of Marine and Environmental Technology, University of Maryland Center for Environmental Science, Baltimore, MD, 21202, USA
| | - Xiaoxiao Wang
- Key Laboratory of Coastal Biology and Biological Resource Utilization, Yantai Institute of Coastal Zone Research, Chinese Academy of Sciences, Yantai, 264003, Shandong, China.,Academy of Life Science, Qufu Normal University, Qufu, 273165, Shandong, China
| | - Jianwen Dong
- School of Physics, State Key Laboratory of Optoelectronic Materials and Technologies, Sun Yat-Sen University, Guangzhou, 510275, Guangdong, China
| | - Song Qin
- Key Laboratory of Coastal Biology and Biological Resource Utilization, Yantai Institute of Coastal Zone Research, Chinese Academy of Sciences, Yantai, 264003, Shandong, China. .,Academy of Life Science, Qufu Normal University, Qufu, 273165, Shandong, China.
| | - Fuli Zhao
- School of Physics, State Key Laboratory of Optoelectronic Materials and Technologies, Sun Yat-Sen University, Guangzhou, 510275, Guangdong, China.
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Abstract
Phycobilisomes (PBSs) are extremely large chromophore-protein complexes on the stromal side of the thylakoid membrane in cyanobacteria and red algae. The main function of PBSs is light harvesting, and they serve as antennas and transfer the absorbed energy to the reaction centers of two photosynthetic systems (photosystems I and II). PBSs are composed of phycobiliproteins and linker proteins. How phycobiliproteins and linkers are organized in PBSs and how light energy is efficiently harvested and transferred in PBSs are the fundamental questions in the study of photosynthesis. In this review, the structures of the red algae Griffithsia pacifica and Porphyridium purpureum are discussed in detail, along with the functions of linker proteins in phycobiliprotein assembly and in fine-tuning the energy state of chromophores.
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Affiliation(s)
- Sen-Fang Sui
- State Key Laboratory of Membrane Biology, Beijing Advanced Innovation Center for Structural Biology and Frontier Research Center for Biological Structure, School of Life Sciences, Tsinghua University, Beijing 100084, China;
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5
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Structural basis of energy transfer in Porphyridium purpureum phycobilisome. Nature 2020; 579:146-151. [DOI: 10.1038/s41586-020-2020-7] [Citation(s) in RCA: 61] [Impact Index Per Article: 15.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2019] [Accepted: 12/19/2019] [Indexed: 12/28/2022]
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6
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Li Y, Zhang Z, Paciulli M, Abbaspourrad A. Extraction of phycocyanin-A natural blue colorant from dried spirulina biomass: Influence of processing parameters and extraction techniques. J Food Sci 2020; 85:727-735. [PMID: 31999367 DOI: 10.1111/1750-3841.14842] [Citation(s) in RCA: 26] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2019] [Revised: 09/11/2019] [Accepted: 09/18/2019] [Indexed: 12/12/2022]
Abstract
Phycocyanin, a natural blue colorant, is typically extracted from liquid biomass of Arthrospira platensis, a blue-green algae called spirulina. In this study, we developed a scalable process to extract phycocyanin from dried spirulina biomass. First, we established the optimal ionic strength and pH for the extraction buffer. The results showed that a minimum ionic strength (>5 g/L NaCl) must be maintained to minimize the co-extraction of the green chlorophyll. The optimal pH of the phosphate buffer (100 mM) for phycocyanin extraction is 7.5; however, the pH should be immediately adjusted to 6.0 to 6.5 after the extraction to keep phycocyanin stable. Second, we also investigated three processing techniques, that is, high-pressure processing (HPP), pulsed electric field (PEF), and ultrasonication, to break the cell walls of spirulina and facilitate the release of phycocyanins into extraction buffers. HPP and PEF do not lead to the release of phycocyanin into the extraction buffer. However, ultrasonication breaks down the spirulina into fine particles and releases most of the phycocyanin, along with other impurities, immediately after the treatment. Last, it has been revealed that most of the phycocyanin can be extracted from biomass within 3 hr by phosphate buffer only (pH 7.5, 100 mM) at room temperature. It is concluded that there is no need to treat the rehydrated biomass solution by HPP, PEF, or ultrasonication due to the minimal benefits they brought for the extraction. Based on these results, we proposed an extraction process for the plant production of phycocyanin starting from dried spirulina biomass. PRACTICAL APPLICATIONS: Limited information can be found on the extraction of phycocyanin from dried spirulina biomass, especially how to better preserve the natural blue color of phycocyanin during extraction. We have investigated the method and presented a different view from previous processes. Pulsed electric field, high-pressure processing, and ultrasonication were employed to accelerate the extraction of phycocyanin from dried biomass. However, it was found that, unlike the extraction from live wet biomass, these techniques do not help with the extraction from dried biomass. Based on investigations, we have proposed a process that can be easily scaled up for the commercial production of phycocyanin from dried spirulina biomass.
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Affiliation(s)
- Ying Li
- Dept. of Food Science, College of Agriculture and Life Sciences, Cornell Univ., Ithaca, NY, 14853, U.S.A
| | - Zhong Zhang
- Dept. of Food Science, College of Agriculture and Life Sciences, Cornell Univ., Ithaca, NY, 14853, U.S.A
| | - Maria Paciulli
- Dept. of Food Science, College of Agriculture and Life Sciences, Cornell Univ., Ithaca, NY, 14853, U.S.A.,Dipartimento di Scienze degli Alimenti e del Farmaco, Parco Area delle Scienze 47/A, 43124, Parma, Italy
| | - Alireza Abbaspourrad
- Dept. of Food Science, College of Agriculture and Life Sciences, Cornell Univ., Ithaca, NY, 14853, U.S.A
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Chen H, Zheng C, Jiang P, Ji G. Biosynthesis of a Phycocyanin Beta Subunit with Two Noncognate Chromophores in Escherichia coli. Appl Biochem Biotechnol 2019; 191:763-771. [PMID: 31853878 DOI: 10.1007/s12010-019-03219-3] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2019] [Accepted: 12/05/2019] [Indexed: 11/28/2022]
Abstract
Recombinant phycobiliprotein can be used as fluorescent label in immunofluorescence assay. In this study, pathway for phycocyanin beta subunit (CpcB) carrying noncognate chromophore phycoerythrobilin (PEB) and phycourobilin (PUB) was constructed in Escherichia coli. Lyase CpcS and CpcT could catalyze attachment of PEB to Cys84-CpcB and Cys155-CpcB, respectively. However, PEB was attached only to Cys84-CpcB when both CpcS and CpcT were present in E. coli. A dual plasmid expression system was used to control the expression of lyases and the attachment order of PEB to CpcB. The production of PEB-Cys155-CpcB was achieved by L-arabinose-induced expression of CpcS, CpcB, Ho1, and PebS, and then the attachment of PEB to Cys84-CpcB was achieved by IPTG-induced expression of CpcS. The doubly chromophorylated CpcB absorbed light maximally at 497.5 nm and 557.0 nm and fluoresced maximally at 507.5 nm and 566.5 nm. An amount of light energy absorbed by PUB-Cys155-CpcB is transferred to PEB-Cys84-CpcB in doubly chromophorylated CpcB, conferring a large stokes shift of 69 nm for this fluorescent protein. There are interactions between chromophores of CpcB which possibly together with the help of lyases lead to isomerization of PEB-Cys155-CpcB to PUB-Cys155-CpcB.
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Affiliation(s)
- Huaxin Chen
- Key Laboratory of Experimental Marine Biology, Institute of Oceanology Chinese Academy of Sciences, Qingdao, 266071, China. .,Laboratory for Marine Biology and Biotechnology, Qingdao National Laboratory for Marine Science and Technology, Qingdao, 266071, China. .,Center for Ocean Mega-Science, Chinese Academy of Sciences, Qingdao, 266071, China.
| | - Caiyun Zheng
- College of Biotechnology Sericultural Research Institute, Jiangsu University of Science and Technology, Jiangsu, China
| | - Peng Jiang
- Key Laboratory of Experimental Marine Biology, Institute of Oceanology Chinese Academy of Sciences, Qingdao, 266071, China.,Laboratory for Marine Biology and Biotechnology, Qingdao National Laboratory for Marine Science and Technology, Qingdao, 266071, China.,Center for Ocean Mega-Science, Chinese Academy of Sciences, Qingdao, 266071, China
| | - Gengsheng Ji
- College of Biotechnology Sericultural Research Institute, Jiangsu University of Science and Technology, Jiangsu, China
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8
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Adir N, Bar-Zvi S, Harris D. The amazing phycobilisome. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2019; 1861:148047. [PMID: 31306623 DOI: 10.1016/j.bbabio.2019.07.002] [Citation(s) in RCA: 74] [Impact Index Per Article: 14.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/20/2019] [Revised: 06/19/2019] [Accepted: 07/09/2019] [Indexed: 10/26/2022]
Abstract
Cyanobacteria and red-algae share a common light-harvesting complex which is different than all other complexes that serve as photosynthetic antennas - the Phycobilisome (PBS). The PBS is found attached to the stromal side of thylakoid membranes, filling up most of the gap between individual thylakoids. The PBS self assembles from similar homologous protein units that are soluble and contain conserved cysteine residues that covalently bind the light absorbing chromophores, linear tetra-pyrroles. Using similar construction principles, the PBS can be as large as 16.8 MDa (68×45×39nm), as small as 1.2 MDa (24 × 11.5 × 11.5 nm), and in some unique cases smaller still. The PBS can absorb light between 450 nm to 650 nm and in some cases beyond 700 nm, depending on the species, its composition and assembly. In this review, we will present new observations and structures that expand our understanding of the distinctive properties that make the PBS an amazing light harvesting system. At the end we will suggest why the PBS, for all of its excellent properties, was discarded by photosynthetic organisms that arose later in evolution such as green algae and higher plants.
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Affiliation(s)
- Noam Adir
- Schulich Faculty of Chemistry, Technion-Israel Institute of Technology, Haifa 32000, Israel.
| | - Shira Bar-Zvi
- Schulich Faculty of Chemistry, Technion-Israel Institute of Technology, Haifa 32000, Israel
| | - Dvir Harris
- Schulich Faculty of Chemistry, Technion-Israel Institute of Technology, Haifa 32000, Israel
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9
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Bar-Zvi S, Lahav A, Harris D, Niedzwiedzki DM, Blankenship RE, Adir N. Structural heterogeneity leads to functional homogeneity in A. marina phycocyanin. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2018; 1859:544-553. [DOI: 10.1016/j.bbabio.2018.04.007] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/08/2018] [Revised: 04/18/2018] [Accepted: 04/23/2018] [Indexed: 12/31/2022]
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10
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Murton J, Nagarajan A, Nguyen AY, Liberton M, Hancock HA, Pakrasi HB, Timlin JA. Population-level coordination of pigment response in individual cyanobacterial cells under altered nitrogen levels. PHOTOSYNTHESIS RESEARCH 2017; 134:165-174. [PMID: 28733863 PMCID: PMC5645440 DOI: 10.1007/s11120-017-0422-7] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 03/15/2017] [Accepted: 07/05/2017] [Indexed: 06/07/2023]
Abstract
Cyanobacterial phycobilisome (PBS) pigment-protein complexes harvest light and transfer the energy to reaction centers. Previous ensemble studies have shown that cyanobacteria respond to changes in nutrient availability by modifying the structure of PBS complexes, but this process has not been visualized for individual pigments at the single-cell level due to spectral overlap. We characterized the response of four key photosynthetic pigments to nitrogen depletion and repletion at the subcellular level in individual, live Synechocystis sp. PCC 6803 cells using hyperspectral confocal fluorescence microscopy and multivariate image analysis. Our results revealed that PBS degradation and re-synthesis comprise a rapid response to nitrogen fluctuations, with coordinated populations of cells undergoing pigment modifications. Chlorophyll fluorescence originating from photosystem I and II decreased during nitrogen starvation, but no alteration in subcellular chlorophyll localization was found. We observed differential rod and core pigment responses to nitrogen deprivation, suggesting that PBS complexes undergo a stepwise degradation process.
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Affiliation(s)
- Jaclyn Murton
- Bioenergy and Defense Technologies, Sandia National Laboratories, Albuquerque, NM, 87123, USA
| | - Aparna Nagarajan
- Department of Biology, Washington University, St. Louis, MO, 63130, USA
- Renewable and Sustainable Energy Institute, University of Colorado Boulder, Boulder, CO, 80309, USA
| | - Amelia Y Nguyen
- Department of Biology, Washington University, St. Louis, MO, 63130, USA
- United States Environmental Protection Agency, Washington, DC, 20460, USA
| | - Michelle Liberton
- Department of Biology, Washington University, St. Louis, MO, 63130, USA
| | - Harmony A Hancock
- Bioenergy and Defense Technologies, Sandia National Laboratories, Albuquerque, NM, 87123, USA
- Department of Biological Sciences, Old Dominion University, Norfolk, VA, 23529, USA
| | - Himadri B Pakrasi
- Department of Biology, Washington University, St. Louis, MO, 63130, USA
| | - Jerilyn A Timlin
- Bioenergy and Defense Technologies, Sandia National Laboratories, Albuquerque, NM, 87123, USA.
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11
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Chenu A, Keren N, Paltiel Y, Nevo R, Reich Z, Cao J. Light Adaptation in Phycobilisome Antennas: Influence on the Rod Length and Structural Arrangement. J Phys Chem B 2017; 121:9196-9202. [DOI: 10.1021/acs.jpcb.7b07781] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Aurélia Chenu
- Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, Massachusetts 02139, United States
- Singapore-MIT Alliance for Research and Technology, 138602 Singapore
| | - Nir Keren
- Department
of Plant and Environmental Sciences, Alexander Silberman Institute
of Life Sciences, Givat Ram, The Hebrew University of Jerusalem, 91904 Jerusalem, Israel
| | - Yossi Paltiel
- Department
of Plant and Environmental Sciences, Alexander Silberman Institute
of Life Sciences, Givat Ram, The Hebrew University of Jerusalem, 91904 Jerusalem, Israel
| | - Reinat Nevo
- Department
of Biomolecular Sciences, Weizmann Institute of Science, 7610001 Rehovot, Israel
| | - Ziv Reich
- Department
of Biomolecular Sciences, Weizmann Institute of Science, 7610001 Rehovot, Israel
| | - Jianshu Cao
- Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, Massachusetts 02139, United States
- Singapore-MIT Alliance for Research and Technology, 138602 Singapore
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12
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Light harvesting in phototrophic bacteria: structure and function. Biochem J 2017; 474:2107-2131. [DOI: 10.1042/bcj20160753] [Citation(s) in RCA: 82] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2017] [Revised: 04/03/2017] [Accepted: 04/06/2017] [Indexed: 12/23/2022]
Abstract
This review serves as an introduction to the variety of light-harvesting (LH) structures present in phototrophic prokaryotes. It provides an overview of the LH complexes of purple bacteria, green sulfur bacteria (GSB), acidobacteria, filamentous anoxygenic phototrophs (FAP), and cyanobacteria. Bacteria have adapted their LH systems for efficient operation under a multitude of different habitats and light qualities, performing both oxygenic (oxygen-evolving) and anoxygenic (non-oxygen-evolving) photosynthesis. For each LH system, emphasis is placed on the overall architecture of the pigment–protein complex, as well as any relevant information on energy transfer rates and pathways. This review addresses also some of the more recent findings in the field, such as the structure of the CsmA chlorosome baseplate and the whole-cell kinetics of energy transfer in GSB, while also pointing out some areas in need of further investigation.
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13
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Adaptive thermostability of light-harvesting complexes in marine picocyanobacteria. ISME JOURNAL 2016; 11:112-124. [PMID: 27458784 DOI: 10.1038/ismej.2016.102] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/21/2015] [Revised: 04/21/2016] [Accepted: 04/24/2016] [Indexed: 11/08/2022]
Abstract
Marine Synechococcus play a key role in global oceanic primary productivity. Their wide latitudinal distribution has been attributed to the occurrence of lineages adapted to distinct thermal niches, but the physiological and molecular bases of this ecotypic differentiation remain largely unknown. By comparing six strains isolated from different latitudes, we showed that the thermostability of their light-harvesting complexes, called phycobilisomes (PBS), varied according to the average sea surface temperature at strain isolation site. Comparative analyses of thermal unfolding curves of the three phycobiliproteins (PBP) constituting PBS rods suggested that the differences in thermostability observed on whole PBSs relied on the distinct molecular flexibility and stability of their individual components. Phycocyanin was the least thermostable of all rod PBP, constituting a fragility point of the PBS under heat stress. Amino-acid composition analyses and structural homology modeling notably revealed the occurrence of two amino-acid substitutions, which might have a role in the observed differential thermotolerance of this phycobiliprotein among temperature ecotypes. We hypothesize that marine Synechococcus ancestors occurred first in warm niches and that during the colonization of cold, high latitude thermal niches, their descendants have increased the molecular flexibility of PBP to maintain optimal light absorption capacities, this phenomenon likely resulting in a decreased stability of these proteins. This apparent thermoadaptability of marine Synechococcus has most probably contributed to the remarkable ubiquity of these picocyanobacteria in the ocean.
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14
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Liu S, Chen Y, Lu Y, Chen H, Li F, Qin S. Biosynthesis of fluorescent cyanobacterial allophycocyanin trimer in Escherichia coli. PHOTOSYNTHESIS RESEARCH 2010; 105:135-142. [PMID: 20607408 DOI: 10.1007/s11120-010-9574-4] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/27/2009] [Accepted: 06/14/2010] [Indexed: 05/29/2023]
Abstract
Allophycocyanin (APC), a cyanobacterial photosynthetic phycobiliprotein, functions in energy transfer as a light-harvesting protein. One of the prominent spectroscopic characteristics of APC is a strong red-shift in the absorption and emission maxima when monomers are assembled into a trimer. Previously, holo-APC alpha and beta subunits (holo-ApcA and ApcB) were successfully synthesized in Escherichia coli. In this study, both holo-subunits from Synechocystis sp. PCC 6803 were co-expressed in E. coli, and found to self-assemble into trimers. The recombinant APC trimer was purified by metal affinity and size-exclusion chromatography, and had a native structure identical to native APC, as determined by characteristic spectroscopic measurements, fluorescence quantum yield, tryptic digestion analysis, and molecular weight measurements. Combined with results from a study in which only the monomer was formed, our results indicate that bilin synthesis and the subsequent attachment to apo-subunits are important for the successful assembly of APC trimers. This is the first study to report on the assembly of recombinant ApcA and ApcB into a trimer with native structure. Our study provides a promising method for producing better fluorescent tags, as well as a method to facilitate the genetic analysis of APC trimer assembly and biological function.
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Affiliation(s)
- Shaofang Liu
- Key Laboratory of Experimental Marine Biology, Institute of Oceanology, Chinese Academy of Sciences, 266071 Qingdao, People's Republic of China.
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15
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Dines M, Sendersky E, David L, Schwarz R, Adir N. Structural, functional, and mutational analysis of the NblA protein provides insight into possible modes of interaction with the phycobilisome. J Biol Chem 2008; 283:30330-40. [PMID: 18718907 DOI: 10.1074/jbc.m804241200] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The enormous macromolecular phycobilisome antenna complex (>4 MDa) in cyanobacteria and red algae undergoes controlled degradation during certain forms of nutrient starvation. The NblA protein (approximately 6 kDa) has been identified as an essential component in this process. We have used structural, biochemical, and genetic methods to obtain molecular details on the mode of action of the NblA protein. We have determined the three-dimensional structure of the NblA protein from both the thermophilic cyanobacterium Thermosynechococcus vulcanus and the mesophilic cyanobacterium Synechococcus elongatus sp. PCC 7942. The NblA monomer has a helix-loop-helix motif which dimerizes into an open, four-helical bundle, identical to the previously determined NblA structure from Anabaena. Previous studies indicated that mutations to NblA residues near the C terminus impaired its binding to phycobilisome proteins in vitro, whereas the only mutation known to affect NblA function in vivo is located near the protein N terminus. We performed random mutagenesis of the S. elongatus nblA gene which enabled the identification of four additional amino acids crucial for NblA function in vivo. This data shows that essential amino acids are not confined to the protein termini. We also show that expression of the Anabaena nblA gene complements phycobilisome degradation in an S. elongatus NblA-null mutant despite the low homology between NblAs of these cyanobacteria. We propose that the NblA interacts with the phycobilisome via "structural mimicry" due to similarity in structural motifs found in all phycobiliproteins. This suggestion leads to a new model for the mode of NblA action which involves the entire NblA protein.
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Affiliation(s)
- Monica Dines
- Schulich Faculty of Chemistry and Institute of Catalysis, Science, and Technology, Technion-Israel Institute of Technology, Technion City, Haifa 32000, Israel
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