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Yu J, Li Y, Qin Z, Guo S, Li Y, Miao Y, Song C, Chen S, Dai S. Plant Chloroplast Stress Response: Insights from Thiol Redox Proteomics. Antioxid Redox Signal 2020; 33:35-57. [PMID: 31989831 DOI: 10.1089/ars.2019.7823] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Significance: Plant chloroplasts generate reactive oxygen species (ROS) during photosynthesis, especially under stresses. The sulfhydryl groups of protein cysteine residues are susceptible to redox modifications, which regulate protein structure and function, and thus different signaling and metabolic processes. The ROS-governed protein thiol redox switches play important roles in chloroplasts. Recent Advances: Various high-throughput thiol redox proteomic approaches have been developed, and they have enabled the improved understanding of redox regulatory mechanisms in chloroplasts. For example, the thioredoxin-modulated antioxidant enzymes help to maintain cellular ROS homeostasis. The light- and dark-dependent redox regulation of photosynthetic electron transport, the Calvin/Benson cycle, and starch biosynthesis ensures metabolic coordination and efficient energy utilization. In addition, redox cascades link the light with the dynamic changes of metabolites in nitrate and sulfur assimilation, shikimate pathway, and biosynthesis of fatty acid hormone as well as purine, pyrimidine, and thiamine. Importantly, redox regulation of tetrapyrrole and chlorophyll biosynthesis is critical to balance the photodynamic tetrapyrrole intermediates and prevent oxidative damage. Moreover, redox regulation of diverse elongation factors, chaperones, and kinases plays an important role in the modulation of gene expression, protein conformation, and posttranslational modification that contribute to photosystem II (PSII) repair, state transition, and signaling in chloroplasts. Critical Issues: This review focuses on recent advances in plant thiol redox proteomics and redox protein networks toward understanding plant chloroplast signaling, metabolism, and stress responses. Future Directions: Using redox proteomics integrated with biochemical and molecular genetic approaches, detailed studies of cysteine residues, their redox states, cross talk with other modifications, and the functional implications will yield a holistic understanding of chloroplast stress responses.
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Affiliation(s)
- Juanjuan Yu
- Development Center of Plant Germplasm Resources, College of Life Sciences, Shanghai Normal University, Shanghai, China.,Key Laboratory of Saline-alkali Vegetation Ecology Restoration, Ministry of Education, Alkali Soil Natural Environmental Science Center, Northeast Forestry University, Harbin, China.,College of Life Sciences, Henan Normal University, Xinxiang, China
| | - Ying Li
- Key Laboratory of Saline-alkali Vegetation Ecology Restoration, Ministry of Education, Alkali Soil Natural Environmental Science Center, Northeast Forestry University, Harbin, China
| | - Zhi Qin
- Development Center of Plant Germplasm Resources, College of Life Sciences, Shanghai Normal University, Shanghai, China
| | - Siyi Guo
- Institute of Plant Stress Biology, State Key Laboratory of Cotton Biology, Department of Biology, Henan University, Kaifeng, China
| | - Yongfang Li
- College of Life Sciences, Henan Normal University, Xinxiang, China
| | - Yuchen Miao
- Institute of Plant Stress Biology, State Key Laboratory of Cotton Biology, Department of Biology, Henan University, Kaifeng, China
| | - Chunpeng Song
- Institute of Plant Stress Biology, State Key Laboratory of Cotton Biology, Department of Biology, Henan University, Kaifeng, China
| | - Sixue Chen
- Department of Biology, Genetics Institute, Plant Molecular and Cellular Biology Program, Interdisciplinary Center for Biotechnology Research, University of Florida, Gainesville, Florida, USA
| | - Shaojun Dai
- Development Center of Plant Germplasm Resources, College of Life Sciences, Shanghai Normal University, Shanghai, China.,Key Laboratory of Saline-alkali Vegetation Ecology Restoration, Ministry of Education, Alkali Soil Natural Environmental Science Center, Northeast Forestry University, Harbin, China
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Popelka H, Uversky VN, Klionsky DJ. Identification of Atg3 as an intrinsically disordered polypeptide yields insights into the molecular dynamics of autophagy-related proteins in yeast. Autophagy 2015; 10:1093-104. [PMID: 24879155 DOI: 10.4161/auto.28616] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
The mechanism of autophagy relies on complex cell signaling and regulatory processes. Each cell contains many proteins that lack a rigid 3-dimensional structure under physiological conditions. These dynamic proteins, called intrinsically disordered proteins (IDPs) and protein regions (IDPRs), are predominantly involved in cell signaling and regulation. Yet, very little is known about their presence among proteins of the core autophagy machinery. In this work, we characterized the autophagy protein Atg3 from yeast and human along with 2 variants to show that Atg3 is an IDPRs-containing protein and that disorder/order predicted for these proteins from their amino acid sequence corresponds to their experimental characteristics. Based on this consensus, we applied the same prediction methods to all known Atg proteins from Saccharomyces cerevisiae. The data presented here provide an insight into the structural dynamics of each Atg protein. They also show that intrinsic disorder at various levels has to be taken into consideration for about half of the Atg proteins. This work should become a useful tool that will facilitate and encourage exploration of protein intrinsic disorder in autophagy.
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Affiliation(s)
- Hana Popelka
- Life Sciences Institute; University of Michigan; Ann Arbor, MI USA
| | - Vladimir N Uversky
- Department of Molecular Medicine and USF Health Byrd Alzheimer's Research Institute; Morsani College of Medicine; University of South Florida; Tampa, FL USA; Institute for Biological Instrumentation; Russian Academy of Sciences; Moscow Region, Russia
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Midorikawa T, Inoue K. Multiple fates of non-mature lumenal proteins in thylakoids. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2013; 76:73-86. [PMID: 23802992 DOI: 10.1111/tpj.12273] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/11/2013] [Revised: 06/18/2013] [Accepted: 06/24/2013] [Indexed: 06/02/2023]
Abstract
Most proteins found in the thylakoid lumen are synthesized in the cytosol with an N-terminal extension consisting of transient signals for chloroplast import and thylakoid transfer in tandem. The thylakoid-transfer signal is required for protein sorting from the stroma to thylakoids, mainly via the cpSEC or cpTAT pathway, and is removed by the thylakoidal processing peptidase in the lumen. An Arabidopsis mutant lacking one of the thylakoidal processing peptidase homologs, Plsp1, contains plastids with anomalous thylakoids and is seedling-lethal. Furthermore, the mutant plastids accumulate two cpSEC substrates (PsbO and PetE) and one cpTAT substrate (PsbP) as intermediate forms. These properties of plsp1-null plastids suggest that complete maturation of lumenal proteins is a critical step for proper thylakoid assembly. Here we tested the effects of inhibition of thylakoid-transfer signal removal on protein targeting and accumulation by examining the localization of non-mature lumenal proteins in the Arabidopsis plsp1-null mutant and performing a protein import assay using pea chloroplasts. In plsp1-null plastids, the two cpSEC substrates were shown to be tightly associated with the membrane, while non-mature PsbP was found in the stroma. The import assay revealed that inhibition of thylakoid-transfer signal removal did not disrupt cpSEC- and cpTAT-dependent translocation, but prevented release of proteins from the membrane. Interestingly, non-mature PetE2 was quickly degraded under light, and unprocessed PsbO1 and PsbP1 were found in a 440-kDa complex and as a monomer, respectively. These results indicate that the cpTAT pathway may be disrupted in the plsp1-null mutant, and that there are multiple mechanisms to control unprocessed lumenal proteins in thylakoids.
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Affiliation(s)
- Takafumi Midorikawa
- Department of Plant Sciences, University of California, 1 Shields Avenue, Davis, CA, 95616, USA
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Degradation of PsbO by the Deg protease HhoA Is thioredoxin dependent. PLoS One 2012; 7:e45713. [PMID: 23029195 PMCID: PMC3446894 DOI: 10.1371/journal.pone.0045713] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2012] [Accepted: 08/24/2012] [Indexed: 02/02/2023] Open
Abstract
The widely distributed members of the Deg/HtrA protease family play an important role in the proteolysis of misfolded and damaged proteins. Here we show that the Deg protease rHhoA is able to degrade PsbO, the extrinsic protein of the Photosystem II (PSII) oxygen-evolving complex in Synechocystis sp. PCC 6803 and in spinach. PsbO is known to be stable in its oxidized form, but after reduction by thioredoxin it became a substrate for recombinant HhoA (rHhoA). rHhoA cleaved reduced eukaryotic (specifically, spinach) PsbO at defined sites and created distinct PsbO fragments that were not further degraded. As for the corresponding prokaryotic substrate (reduced PsbO of Synechocystis sp. PCC 6803), no PsbO fragments were observed. Assembly to PSII protected PsbO from degradation. For Synechocystis sp. PCC 6803, our results show that HhoA, HhoB, and HtrA are localized in the periplasma and/or at the thylakoid membrane. In agreement with the idea that PsbO could be a physiological substrate for Deg proteases, part of the cellular fraction of the three Deg proteases of Synechocystis sp. PCC 6803 (HhoA, HhoB, and HtrA) was detected in the PSII-enriched membrane fraction.
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Popelka H, Yocum C. Probing the N-terminal sequence of spinach PsbO: evidence that essential threonine residues bind to different functional sites in eukaryotic photosystem II. PHOTOSYNTHESIS RESEARCH 2012; 112:117-128. [PMID: 22614952 DOI: 10.1007/s11120-012-9745-6] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/27/2012] [Accepted: 05/03/2012] [Indexed: 06/01/2023]
Abstract
The N-terminal ¹E-⁶L domain of the manganese-stabilizing protein (PsbO) from spinach prevents non-specific binding of the subunit to photosystem II (PSII) and deletions of the ¹E-⁷T or ¹E-¹⁵T sequences from the PsbO N-terminus reduce or impair, respectively, functional binding of PsbO to PSII (Popelkova et al., Biochemistry 42:6193-6200, 2003). The work presented here provides deeper insights into the interaction of PsbO with PSII. The data show that a single mutation, ¹⁵T → A in mature PsbO from spinach reduces the stoichiometry of its functional binding from two to one subunit per PSII and decreases reconstitution of activity to about 45 % of the wild-type control. Replacement of the ¹E-⁶L domain with ⁶M in the T15A PsbO mutant has no additional negative effect on recovery of O₂ evolution activity, but it significantly weakens both functional and nonspecific binding of the truncated mutant to PSII. These results suggest that the ¹⁵T side-chain by itself is essential for binding of one of two PsbO subunits to eukaryotic PSII and that specific PSII-binding sites for PsbO are distinguishable; one PSII-binding site does not require PsbO-¹⁵T and probably interacts with the other N-terminal domain of PsbO. Identity of the latter domain is revealed by a requirement for the presence of the ¹E-⁶L sequence that is shown here to be necessary for high-affinity binding of PsbO to PSII. When combined with previous results, the data presented here lead to a more detailed model for PsbO binding in eukaryotic PSII.
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Affiliation(s)
- Hana Popelka
- Department of Molecular, Cellular, and Developmental Biology, The University of Michigan, Ann Arbor, MI 48109-1048, USA.
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6
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Karamoko M, Cline S, Redding K, Ruiz N, Hamel PP. Lumen Thiol Oxidoreductase1, a disulfide bond-forming catalyst, is required for the assembly of photosystem II in Arabidopsis. THE PLANT CELL 2011; 23:4462-75. [PMID: 22209765 PMCID: PMC3269877 DOI: 10.1105/tpc.111.089680] [Citation(s) in RCA: 73] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/27/2011] [Revised: 11/15/2011] [Accepted: 12/13/2011] [Indexed: 05/18/2023]
Abstract
Here, we identify Arabidopsis thaliana Lumen Thiol Oxidoreductase1 (LTO1) as a disulfide bond-forming enzyme in the thylakoid lumen. Using topological reporters in bacteria, we deduced a lumenal location for the redox active domains of the protein. LTO1 can partially substitute for the proteins catalyzing disulfide bond formation in the bacterial periplasm, which is topologically equivalent to the plastid lumen. An insertional mutation within the LTO1 promoter is associated with a severe photoautotrophic growth defect. Measurements of the photosynthetic activity indicate that the lto1 mutant displays a limitation in the electron flow from photosystem II (PSII). In accordance with these measurements, we noted a severe depletion of the structural subunits of PSII but no change in the accumulation of the cytochrome b(6)f complex or photosystem I. In a yeast two-hybrid assay, the thioredoxin-like domain of LTO1 interacts with PsbO, a lumenal PSII subunit known to be disulfide bonded, and a recombinant form of the molecule can introduce a disulfide bond in PsbO in vitro. The documentation of a sulfhydryl-oxidizing activity in the thylakoid lumen further underscores the importance of catalyzed thiol-disulfide chemistry for the biogenesis of the thylakoid compartment.
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Affiliation(s)
- Mohamed Karamoko
- Department of Molecular Genetics and Department of Molecular and Cellular Biochemistry, The Ohio State University, Columbus, Ohio 43210
| | - Sara Cline
- Department of Molecular Genetics and Department of Molecular and Cellular Biochemistry, The Ohio State University, Columbus, Ohio 43210
- Plant Cellular and Molecular Biology Graduate Program, The Ohio State University, Columbus, Ohio 43210
| | - Kevin Redding
- Department of Chemistry and Biochemistry, Arizona State University, Tempe, Arizona 85287
| | - Natividad Ruiz
- Department of Microbiology, The Ohio State University, Columbus, Ohio 43210
| | - Patrice P. Hamel
- Department of Molecular Genetics and Department of Molecular and Cellular Biochemistry, The Ohio State University, Columbus, Ohio 43210
- Plant Cellular and Molecular Biology Graduate Program, The Ohio State University, Columbus, Ohio 43210
- Address correspondence to
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Popelkova H, Yocum CF. PsbO, the manganese-stabilizing protein: Analysis of the structure–function relations that provide insights into its role in photosystem II. JOURNAL OF PHOTOCHEMISTRY AND PHOTOBIOLOGY B-BIOLOGY 2011; 104:179-90. [DOI: 10.1016/j.jphotobiol.2011.01.015] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/25/2010] [Revised: 01/13/2011] [Accepted: 01/14/2011] [Indexed: 01/07/2023]
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8
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Slowik D, Rossmann M, Konarev PV, Irrgang KD, Saenger W. Structural Investigation of PsbO from Plant and Cyanobacterial Photosystem II. J Mol Biol 2011; 407:125-37. [DOI: 10.1016/j.jmb.2011.01.013] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2010] [Revised: 12/31/2010] [Accepted: 01/07/2011] [Indexed: 02/02/2023]
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9
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Bricker TM, Frankel LK. Auxiliary functions of the PsbO, PsbP and PsbQ proteins of higher plant Photosystem II: a critical analysis. JOURNAL OF PHOTOCHEMISTRY AND PHOTOBIOLOGY B-BIOLOGY 2011; 104:165-78. [PMID: 21353792 DOI: 10.1016/j.jphotobiol.2011.01.025] [Citation(s) in RCA: 60] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/03/2010] [Revised: 01/25/2011] [Accepted: 01/31/2011] [Indexed: 01/08/2023]
Abstract
Numerous studies over the last 25 years have established that the extrinsic PsbO, PsbP and PsbQ proteins of Photosystem II play critically important roles in maintaining optimal manganese, calcium and chloride concentrations at the active site of Photosystem II. Chemical or genetic removal of these components induces multiple and profound defects in Photosystem II function and oxygen-evolving complex stability. Recently, a number of studies have indicated possible additional roles for these proteins within the photosystem. These include putative enzymatic activities, regulation of reaction center protein turnover, modulation of thylakoid membrane architecture, the mediation of PS II assembly/stability, and effects on the reducing side of the photosystem. In this review we will critically examine the findings which support these auxiliary functions and suggest additional lines of investigations which could clarify the nature of the functional interactions of these proteins with the photosystem.
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Affiliation(s)
- Terry M Bricker
- Department of Biological Sciences, Division of Biochemistry and Molecular Biology, Louisiana State University, Baton Rouge, LA 70803, USA.
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10
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Roose JL, Yocum CF, Popelkova H. Function of PsbO, the Photosystem II Manganese-Stabilizing Protein: Probing the Role of Aspartic Acid 157. Biochemistry 2010; 49:6042-51. [DOI: 10.1021/bi100303f] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Affiliation(s)
- Johnna L. Roose
- Department of Biological Sciences, Division of Biochemistry and Molecular Biology, Louisiana State University, Baton Rouge, Louisiana 70803
| | - Charles F. Yocum
- Department of Molecular, Cellular, and Developmental Biology
- Department of Chemistry
| | - Hana Popelkova
- Department of Molecular, Cellular, and Developmental Biology
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11
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Popelkova H, Commet A, Yocum CF. Asp157 is required for the function of PsbO, the photosystem II manganese stabilizing protein. Biochemistry 2010; 48:11920-8. [PMID: 19894760 DOI: 10.1021/bi9016999] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
PsbO, the photosystem II manganese stabilizing protein, contains an aspartate residue [Asp157 (spinach numbering)], which is highly conserved in eukaryotic and prokaryotic PsbOs. The homology model of the PSII-bound conformation of spinach PsbO presented here positions Asp157 in the large flexible loop of the protein. We have characterized site-directed mutants (D157N, D157E, and D157K) of spinach PsbO that were rebound to PsbO-depleted PSII to probe the role of Asp157. Structural data revealed that PsbO Asp157 mutants exhibit near-wild-type solution structure at 25 degrees C, but functional analyses of the mutants showed that these are the first genetically modified PsbO proteins from spinach that combine wild-type PSII binding behavior with significantly impaired O(2) evolution activity; all of the mutants reconstituted approximately 30% of control O(2) evolution activity. PsbO Asp157 has been proposed to be a part of a putative H(2)O/H(+) channel that links the active site of the oxygen-evolving complex with the lumen [De Las Rivas, J., and Barber, J. (2004) Photosynth. Res. 81, 329-343]. Unsuccessful attempts to use chemical rescue to enhance the activity restored by Asp157 mutants could indicate that this residue is not involved in a proton transfer network. It is shown, however, that these mutants are deficient in restoring efficient Cl(-) retention by PSII.
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Affiliation(s)
- Hana Popelkova
- Department of Molecular, Cellular and Developmental Biology, The University of Michigan,Ann Arbor, Michigan 48109-1048, USA.
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Nikitina J, Shutova T, Melnik B, Chernyshov S, Marchenkov V, Semisotnov G, Klimov V, Samuelsson G. Importance of a single disulfide bond for the PsbO protein of photosystem II: protein structure stability and soluble overexpression in Escherichia coli. PHOTOSYNTHESIS RESEARCH 2008; 98:391-403. [PMID: 18709441 DOI: 10.1007/s11120-008-9327-9] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/28/2008] [Accepted: 07/01/2008] [Indexed: 05/09/2023]
Abstract
PsbO protein is an important constituent of the water-oxidizing complex, located on the lumenal side of photosystem II. We report here the efficient expression of the spinach PsbO in E. coli where the solubility depends entirely on the formation of the disulfide bond. The PsbO protein purified from a pET32 system that includes thioredoxin fusion is properly folded and functionally active. Urea unfolding experiments imply that the reduction of the single disulfide bridge decreases stability of the protein. Analysis of inter-residue contact density through the PsbO molecule shows that Cys51 is located in a cluster with high contact density. Reduction of the Cys28-Cys51 bond is proposed to perturb the packing interactions in this cluster and destabilize the protein as a whole. Taken together, our results give evidence that PsbO exists in solution as a compact highly ordered structure, provided that the disulfide bridge is not reduced.
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Affiliation(s)
- Julia Nikitina
- Umeå Plant Science Centre, Department of Plant Physiology, Umeå University, 901 87 Umea, Sweden
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Williamson AK. Structural and functional aspects of the MSP (PsbO) and study of its differences in thermophilic versus mesophilic organisms. PHOTOSYNTHESIS RESEARCH 2008; 98:365-89. [PMID: 18780158 DOI: 10.1007/s11120-008-9353-7] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/29/2008] [Accepted: 08/06/2008] [Indexed: 05/16/2023]
Abstract
The Manganese Stabilizing Protein (MSP) of Photosystem II (PSII) is a so-called extrinsic subunit, which reversibly associates with the other membrane-bound PSII subunits. The MSP is essential for maximum rates of O(2) production under physiological conditions as stabilizes the catalytic [Mn(4)Ca] cluster, which is the site of water oxidation. The function of the MSP subunit in the PSII complex has been extensively studied in higher plants, and the structure of non-PSII associated MSP has been studied by low-resolution biophysical techniques. Recently, crystal structures of PSII from the thermophilic cyanobacterium Thermosynechococcus elongatus have resolved the MSP subunit in its PSII-associated state. However, neither any crystal structure is available yet for MSP from mesophilic organisms, higher plants or algae nor has the non-PSII associated form of MSP been crystallized. This article reviews the current understanding of the structure, dynamics, and function of MSP, with a particular focus on properties of the MSP from T. elongatus that may be attributable to the thermophilic ecology of this organism rather than being general features of MSP.
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Affiliation(s)
- Adele K Williamson
- Research School of Biological Sciences, the Australian National University, Canberra 0200, Australia.
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Ströher E, Dietz KJ. The dynamic thiol-disulphide redox proteome of the Arabidopsis thaliana chloroplast as revealed by differential electrophoretic mobility. PHYSIOLOGIA PLANTARUM 2008; 133:566-83. [PMID: 18433418 DOI: 10.1111/j.1399-3054.2008.01103.x] [Citation(s) in RCA: 58] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/04/2023]
Abstract
The dynamics of the thiol-disulphide redox proteome is central to cell function and its regulation. Altered mobility of proteins in the oxidized and reduced state allows the MS-based identification of those thiol-disulphide proteins that undergo major conformational changes. A proteomic approach was taken with thylakoid-bound, luminal and ribulose-1,5-bisphosphate carboxylase/oxygenase (Rubisco)-less stromal subproteome fractions of the chloroplast from Arabidopsis thaliana. Among the 49 verified polypeptides were 22 novel redox proteins, previously not reported as being part of the redox proteome. Among the redox-affected proteins were PsbA (D1), PsaA1 and PsaF, chloroplast monodehydroascorbate reductase and also the Deg1 protease. Recombinant Deg1 and Deg2 revealed redox dependence of their proteolytic activity. The data provide new insights into the redox network of the chloroplast.
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Affiliation(s)
- Elke Ströher
- Faculty of Biology, University of Bielefeld, Univ. Str. 25, D-33501 Bielefeld, Germany
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Wyman AJ, Popelkova H, Yocum CF. Site-directed mutagenesis of conserved C-terminal tyrosine and tryptophan residues of PsbO, the photosystem II manganese-stabilizing protein, alters its activity and fluorescence properties. Biochemistry 2008; 47:6490-8. [PMID: 18500826 DOI: 10.1021/bi800225m] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
The extrinsic photosystem II PsbO subunit (manganese-stabilizing protein) contains near-UV CD signals from its complement of aromatic amino acid residues (one Trp, eight Tyr, and 13 Phe residues). Acidification, N-bromosuccinimide modification of Trp, reduction or elimination of a disulfide bond, or deletion of C-terminal amino acids abolishes these signals. Site-directed mutations that substitute Phe for Trp241 and Tyr242, near the C-terminus of PsbO, were used to examine the contribution of these residues to the activity and spectral properties of the protein. Although this substitution is, in theory, conservative, neither mutant binds efficiently to PSII, even though these proteins appear to retain wild-type solution structures. Removal of six residues from the N-terminus of the W241F mutant restores activity to near-wild-type levels. The near-UV CD spectra of the mutants are modified; well-defined Tyr and Trp peaks are lost. Characterizations of the fluorescence spectra of the full-length WF and YF mutants indicate that Y242 contributes significantly to PsbO's Tyr fluorescence emission and that an excited-state tyrosinate could be present in PsbO. Deletion of W241 shows that this residue is a major contributor to PsbO's fluorescence emission. Loss of function is consistent with the proposal that a native C-terminal domain is required for PsbO binding and activity, and restoration of activity by deletion of N-terminal amino acids may provide some insights into the evolution of this important photosynthetic protein.
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Affiliation(s)
- Aaron J Wyman
- Department of Molecular, Cellular and Developmental Biology, The University of Michigan, Ann Arbor, Michigan 48109-1048, USA
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Wyman AJ, Yocum CF. Structure and activity of the photosystem II manganese-stabilizing protein: role of the conserved disulfide bond. PHOTOSYNTHESIS RESEARCH 2005; 85:359-72. [PMID: 16170637 DOI: 10.1007/s11120-005-7385-9] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/21/2005] [Accepted: 05/13/2005] [Indexed: 05/04/2023]
Abstract
The 33-kDa manganese-stabilizing protein (MSP) of Photosystem II (PS II) maintains the functional stability of the Mn cluster in the enzyme's active site. This protein has been shown to possess characteristics similar to those of the intrinsically disordered, or natively unfolded proteins. Alternately it was proposed that MSP should be classified as a molten globule, based in part on the hypothesis that its lone disulfide bridge is necessary for structural stability and function in solution. A site-directed mutant MSP (C28A,C51A) that eliminates the disulfide bond reconstitutes O(2) evolution activity and binds to MSP-free PS II preparations at wild-type levels. This mutant was further characterized by incubation at 90 degrees C to determine the effect of loss of the disulfide bridge on MSP thermostability and solution structure. After heating at 90 degrees C for 20 min, C28A,C51A MSP was still able to bind to PS II preparations at molar stoichiometries similar to those of WT MSP and reconstitute O(2) evolution activity. A fraction of the protein aggregates upon heating, but after resolubilization, it regains the ability to bind to PS II and reconstitute O(2) evolution activity. Characterization of the solution structure of C28A,C51A MSP, using CD spectroscopy, UV absorption spectroscopy, and gel filtration chromatography, revealed that the mutant has a more disordered solution structure than WT MSP. The disulfide bond is therefore unnecessary for MSP function and the intrinsically disordered characteristics of MSP are not dependent on its presence. However, the disulfide bond does play a role in the solution structure of MSP in vivo, as evidenced by the lability of a C20S MSP mutation in Synechocystis 6803.
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Affiliation(s)
- Aaron J Wyman
- Department of Molecular, Cellular and Developmental Biology, University of Michigan, Ann Arbor, MI, 48109-1048, USA
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Wyman AJ, Yocum CF. Assembly and function of the photosystem II manganese stabilizing protein: lessons from its natively unfolded behavior. PHOTOSYNTHESIS RESEARCH 2005; 84:283-8. [PMID: 16049787 DOI: 10.1007/s11120-004-7759-4] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/16/2004] [Accepted: 12/16/2004] [Indexed: 05/03/2023]
Abstract
The Photosystem II (PS II) manganese stabilizing protein (MSP) possesses characteristics, including thermostability, ascribed to the natively unfolded class of proteins (Lydakis-Simantiris et al. (1999) Biochemistry 38: 404-414). A site-directed mutant of MSP, C28A, C51A, which lacks the -S-S- bridge, also binds to PS II at wild-type levels and reconstitutes oxygen evolution activity [Betts et al. (1996) Biochim Biophys Acta 1274: 135-142], although the mutant protein is even more disordered in solution. Both WT and C28A, C51A MSP aggregate upon heating, but an examination of the effects of protein concentration and pH on heat-induced aggregation showed that each MSP species exhibited greater resistance to aggregation at a pH near their pI (5.2) than do either bovine serum albumin (BSA) or carbonic anhydrase, which were used as model water soluble proteins. Increases in pH above the pI of the MSPs and BSA enhanced their aggregation resistance, a behavior which can be predicted from their charge (MSP) or a combination of charge and stabilization by -S-S- bonds (BSA). In the case of aggregation resistance by MSP, this is likely to be an important factor in its ability to avoid unproductive self-association reactions in favor of formation of the protein-protein interactions that lead to formation of the functional oxygen evolving complex.
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Affiliation(s)
- Aaron J Wyman
- Department of Molecular, Cellular, and Developmental Biology, The University of Michigan-Ann Arbor, MI 48109, USA
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Murakami R, Ifuku K, Takabayashi A, Shikanai T, Endo T, Sato F. Functional dissection of two Arabidopsis PsbO proteins. FEBS J 2005; 272:2165-75. [PMID: 15853801 DOI: 10.1111/j.1742-4658.2005.04636.x] [Citation(s) in RCA: 73] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
PsbO protein is an extrinsic subunit of photosystem II (PSII) and has been proposed to play a central role in stabilization of the catalytic manganese cluster. Arabidopsis thaliana has two psbO genes that express two PsbO proteins; PsbO1 and PsbO2. We reported previously that a mutant plant that lacked PsbO1 (psbo1) showed considerable growth retardation despite the presence of PsbO2 [Murakami, R., Ifuku, K., Takabayashi, A., Shikanai, T., Endo, T., and Sato, F. (2002) FEBS Lett523, 138-142]. In the present study, we characterized the functional differences between PsbO1 and PsbO2. We found that PsbO1 is the major isoform in the wild-type, and the amount of PsbO2 in psbo1 was significantly less than the total amount of PsbO in the wild-type. The amount of PsbO as well as the efficiency of PSII in psbo1 increased as the plants grew; howeVER, it neVER reached the total PsbO level observed in the wild-type, suggesting that the poor activity of PSII in psbo1 was caused by a shortage of PsbO. In addition, an in vitro reconstitution experiment using recombinant PsbOs and urea-washed PSII particles showed that oxygen evolution was better recoVERed by PsbO1 than by PsbO2. Further analysis using chimeric and mutated PsbOs suggested that the amino acid changes Val186-->Ser, Leu246-->Ile, and Val204-->Ile could explain the functional difference between the two PsbOs. Therefore we concluded that both the lower expression level and the inferior functionality of PsbO2 are responsible for the phenotype observed in psbo1.
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Affiliation(s)
- Reiko Murakami
- Division of Integrated Life Sciences, Graduate School of Biostudies, Kyoto University, Kyoto, Japan
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Heide H, Kalisz HM, Follmann H. The oxygen evolving enhancer protein 1 (OEE) of photosystem II in green algae exhibits thioredoxin activity. JOURNAL OF PLANT PHYSIOLOGY 2004; 161:139-49. [PMID: 15022827 DOI: 10.1078/0176-1617-01033] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/20/2023]
Abstract
A thioredoxin-like chloroplast protein of the fructosebisphosphatase-stimulating f-type, but with an unusually high molecular mass of 28 kDa has previously been identified and purified to homogeneity in a fractionation scheme for resolution of the acid- and heat-stable, regular-size (12kDa) thioredoxins of the unicellular green algae, Scenedesmus obliquus. An apparently analogous protein of 26 kDa was described in a cyanobacterium, Anabaena sp., but no such large thioredoxin species f exists in the thioredoxin profiles of higher plants. The structure of the 28 kDa protein, which had been envisaged to represent a precursor, or fusion product of the two more specialized, common chloroplast thioredoxins f and m has now been determined by amino acid sequencing. Although it exhibits virtually all the properties and enzyme-modulating activities of a thioredoxin proper this algal protein, surprisingly, does not belong to the thioredoxin family of small redox proteins but is identical with OEE (oxygen evolving enhancer) protein 1, an auxiliary component of the photosystem II manganese cluster. Extracts of Chlorella vulgaris and Chlamydomonas reinhardtii also contain heat-stable protein fractions of 23-26 kDa capable of specifically stimulating chloroplast fructosebisphosphatase in vitro. In contrast, OEE protein 1 from spinach is not able to modulate FbPase or NADP malate dehydrogenase from spinach chloroplasts. A dual function of the OEE protein in algal photosynthesis is envisaged.
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Affiliation(s)
- Heinrich Heide
- Fachbereich Biologie-Chemie der Universität Kassel, D-34109 Kassel, Germany
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20
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Nowaczyk M, Berghaus C, Stoll R, Rögner M. Preliminary structural characterisation of the 33 kDa protein (PsbO) in solution studied by site-directed mutagenesis and NMR spectroscopy. Phys Chem Chem Phys 2004. [DOI: 10.1039/b407316a] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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21
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Sachs RK, Halverson KM, Barry BA. Specific isotopic labeling and photooxidation-linked structural changes in the manganese-stabilizing subunit of photosystem II. J Biol Chem 2003; 278:44222-9. [PMID: 12941934 DOI: 10.1074/jbc.m307148200] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Photosystem II (PSII) oxidizes water to molecular oxygen; the catalytic site is a cluster of four manganese ions. The catalytic site undergoes four sequential light-driven oxidation steps to form oxygen; these sequentially oxidized states are referred to as the Sn states, where n refers to the number of oxidizing equivalents stored. The extrinsic manganese stabilizing protein (MSP) of PSII influences the efficiency and stability of the manganese cluster, as well as the rates of the S state transitions. To understand how MSP influences photosynthetic water oxidation, we have employed isotope editing and difference Fourier transform infrared spectroscopy. MSP was expressed in Escherichia coli under conditions in which MSP aspartic and glutamic acid residues label at yields of 65 and 41%, respectively. Asparagine and glutamine were also labeled by this approach. GC/MS analysis was consistent with minimal scrambling of label into other amino acid residues and with no significant scrambling into the peptide bond. Selectively labeled MSP was then reconstituted to PSII, which had been stripped of native MSP. Difference Fourier transform infrared spectroscopy was used to probe the S1QA to S2QA- transition at 200 K, as well as the S1QB to S2QB- transition at 277 K. These experiments show that aspargine, glutamine, and glutamate residues in MSP are perturbed by photooxidation of manganese during the S1 to S2 transition.
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Affiliation(s)
- Roseann K Sachs
- Department of Biochemistry, Molecular Biology, and Biophysics, University of Minnesota, St. Paul, Minnesota 55108, USA
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22
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Shutova T, Villarejo A, Zietz B, Klimov V, Gillbro T, Samuelsson G, Renger G. Comparative studies on the properties of the extrinsic manganese-stabilizing protein from higher plants and of a synthetic peptide of its C-terminus. BIOCHIMICA ET BIOPHYSICA ACTA 2003; 1604:95-104. [PMID: 12765766 DOI: 10.1016/s0005-2728(03)00025-2] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
The present study describes a comparative analysis on the fluorescence properties of the manganese-stabilizing protein (MSP), a synthetic peptide corresponding to its C terminus and a 7:1 (molar ratio) mixture of N-acetyl-tyrosine and N-acetyl-tryptophan, respectively, together with reconstitution experiments of oxygen evolution in MSP-depleted photosystem II (PS II) membrane fragments. It is found: (i) at neutral pH, the fluorescence from Trp(241) is strongly diminished in MSP solutions, whereas it highly dominates the overall emission from the C-terminus peptide; (ii) at alkaline pH, the emission of Tyr and Trp is quenched in both, MSP and C-terminus peptide, with increasing pH but the decline curve is shifted by about two pH units towards the alkaline region in MSP; (iii) a drastically different pattern emerges in the 7:1 mixture where the Trp emission even slightly increases at high pH; (iv) the anisotropy of the fluorescence emission is wavelength-independent (310-395 nm) and indicative of one emitter type (Trp) in the C-terminus peptide and of two emitter types (Tyr, Trp) in MSP; and (v) in MSP-depleted PS II membrane fragments the oxygen evolution is restored (up to 85% of untreated control) by rebinding of MSP but not by the C-terminus peptide, however, the presence of the latter diminishes the restoration effect of MSP. A quenching mechanism of Trp fluorescence by a next neighbored tyrosinate in the peptide chain is proposed and the relevance of the C terminus of MSP briefly discussed.
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Affiliation(s)
- T Shutova
- Department of Plant Physiology, Umeå Plant Science Centre, Umeå University, Sweden
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23
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Murakami R, Ifuku K, Takabayashi A, Shikanai T, Endo T, Sato F. Characterization of an Arabidopsis thaliana mutant with impaired psbO, one of two genes encoding extrinsic 33-kDa proteins in photosystem II. FEBS Lett 2002; 523:138-42. [PMID: 12123820 DOI: 10.1016/s0014-5793(02)02963-0] [Citation(s) in RCA: 61] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
A 33-kDa protein component of the oxygen-evolving complex in photosystem II is essential for photosynthesis, and it has been believed that mutants with deletion of this 33-kDa protein are not found in higher plants. We report here the first isolation of an Arabidopsis thaliana mutant with a defect in one of the genes for the 33-kDa proteins, psbO, and an intact gene (psbO2). This mutant showed considerable growth retardation, suggesting that there is a functional difference between psbO and psbO2.
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Affiliation(s)
- Reiko Murakami
- Division of Integrated Life Sciences, Graduate School of Biostudies, Kyoto University, 606-8502, Kyoto, Japan
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24
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Pueyo JJ, Alfonso M, Andrés C, Picorel R. Increased tolerance to thermal inactivation of oxygen evolution in spinach Photosystem II membranes by substitution of the extrinsic 33-kDa protein by its homologue from a thermophilic cyanobacterium. BIOCHIMICA ET BIOPHYSICA ACTA 2002; 1554:29-35. [PMID: 12034468 DOI: 10.1016/s0005-2728(02)00208-6] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Photosynthetic oxygen evolution is an extremely heat-sensitive process and incubation of spinach Photosystem II (PSII) membranes at 40 degrees C for only several minutes leads to its complete inactivation. Substitution experiments of the spinach 33-kDa manganese stabilizing protein by a homologue protein, isolated either from the thermophilic cyanobacterium Phormidium laminosum, or from Escherichia coli as a recombinant thermophilic cyanobacterial protein, showed a significant increase in tolerance to heat inactivation of the oxygen-evolving activity. The results allow us to suggest that thermal inactivation of oxygen evolution in higher plant PSII membranes is due to dissociation of the 33-kDa protein as a consequence of temperature-induced conformational changes, and stabilization can be provided by substitution by a thermostable homologue whose secondary structure and binding to PSII remain unaltered at moderately high temperatures.
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Affiliation(s)
- José J Pueyo
- Estación Experimental de Aula Dei (CSIC), Apdo. 202, E-50080 Zaragoza, Spain.
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25
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Pazos F, Heredia P, Valencia A, de las Rivas J. Threading structural model of the manganese-stabilizing protein PsbO reveals presence of two possible beta-sandwich domains. Proteins 2001; 45:372-81. [PMID: 11746685 DOI: 10.1002/prot.10012] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
The manganese-stabilizing protein (PsbO) is an essential component of photosystem II (PSII) and is present in all oxyphotosynthetic organisms. PsbO allows correct water splitting and oxygen evolution by stabilizing the reactions driven by the manganese cluster. Despite its important role, its structure and detailed functional mechanism are still unknown. In this article we propose a structural model based on fold recognition and molecular modeling. This model has additional support from a study of the distribution of characteristics of the PsbO sequence family, such as the distribution of conserved, apolar, tree-determinants, and correlated positions. Our threading results consistently showed PsbO as an all-beta (beta) protein, with two homologous beta domains of approximately 120 amino acids linked by a flexible Proline-Glycine-Glycine (PGG) motif. These features are compatible with a general elongated and flexible architecture, in which the two domains form a sandwich-type structure with Greek key topology. The first domain is predicted to include 8 to 9 beta-strands, the second domain 6 to 7 beta-strands. An Ig-like beta-sandwich structure was selected as a template to build the 3-D model. The second domain has, between the strands, long-loops rich in Pro and Gly that are difficult to model. One of these long loops includes a highly conserved region (between P148 and P174) and a short alpha-helix (between E181 and N188)). These regions are characteristic parts of PsbO and show that the second domain is not so similar to the template. Overall, the model was able to account for much of the experimental data reported by several authors, and it would allow the detection of key residues and regions that are proposed in this article as essential for the structure and function of PsbO.
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Affiliation(s)
- F Pazos
- Centro Nacional de Biotecnología, Consejo Superior de Investigaciones Científicas, Madrid, Spain
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26
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Betts SD, Lydakis-Simantiris N, Ross JR, Yocum CF. The carboxyl-terminal tripeptide of the manganese-stabilizing protein is required for quantitative assembly into photosystem II and for high rates of oxygen evolution activity. Biochemistry 1998; 37:14230-6. [PMID: 9760261 DOI: 10.1021/bi981305h] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The extrinsic manganese stabilizing protein of photosystem II is required for Mn retention by the O2-evolving complex, accelerates the rate of O2 evolution, and protects photosytem II against photoinhibition. We report results from studies of the in vitro reconstitution of spinach photosytem II with recombinant manganese stabilizing protein with C-terminal deletions of two, three, and four amino acids. The deletions were the result of amber mutations introduced by site-directed mutagenesis. Removal of the C-terminal dipeptide (Glu-Gln) did not diminish the ability of the manganese stabilizing protein either to rebind to or to restore high rates of O2 evolution to photosystem II preparations depleted of the native protein. Deletion of the C-terminal tripeptide (Leu-Glu-Gln) resulted in weakened but specific binding of manganese stabilizing protein to photosystem II and minimal recovery of O2 evolution activity. Removal of the C-terminal tetrapeptide (Gln-Leu-Glu-Gln) eliminated the ability of the subunit to interact stably with all of its available binding sites on photosystem II, as evidenced by the fact that this mutant was totally inactive in restoring O2 evolution activity. Evidence is presented to indicate that these mutational effects on the binding and function of the manganese stabilizing protein may be due to major changes in tertiary structure. The truncation mutations lacking either the C-terminal tri- or tetrapeptide exhibit apparent size increases of 25 and 40%, respectively, when compared either to a mutant lacking the C-terminal dipeptide or to the wild-type protein.
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Affiliation(s)
- S D Betts
- Department of Biology, University of Michigan, Ann Arbor 48109-1048, USA
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27
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Enami I, Kamo M, Ohta H, Takahashi S, Miura T, Kusayanagi M, Tanabe S, Kamei A, Motoki A, Hirano M, Tomo T, Satoh K. Intramolecular cross-linking of the extrinsic 33-kDa protein leads to loss of oxygen evolution but not its ability of binding to photosystem II and stabilization of the manganese cluster. J Biol Chem 1998; 273:4629-34. [PMID: 9468521 DOI: 10.1074/jbc.273.8.4629] [Citation(s) in RCA: 60] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
The extrinsic 33-kDa protein of photosystem II (PSII) was intramolecularly cross-linked by a zero-length cross-linker, 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide. The resulting cross-linked 33-kDa protein rebound to urea/NaCl-washed PSII membranes, which stabilized the binding of manganese as effectively as the untreated 33-kDa protein. In contrast, the oxygen evolution was not restored by binding of the cross-linked protein, indicating that the binding and manganese-stabilizing capabilities of the 33-kDa protein are retained but its reactivating ability is lost by intramolecular cross-linking of the protein. From measurements of CD spectra at high temperatures, the secondary structure of the intramolecularly cross-linked 33-kDa protein was found to be stabilized against heat treatment at temperatures 20 degrees C higher than that of the untreated 33-kDa protein, suggesting that structural flexibility of the 33-kDa protein was much decreased by the intramolecular cross-linking. The rigid structure is possibly responsible for the loss of the reactivating ability of the 33-kDa protein, which implies that binding of the 33-kDa protein to PSII is accompanied by a conformational change essential for the reactivation of oxygen evolution. Peptide mapping, N-terminal sequencing, and mass spectroscopic analysis of protease-digested products of the intramolecularly cross-linked 33-kDa protein revealed that cross-linkings occurred between the amino group of Lys48 and the carboxyl group of Glu246, and between the carboxyl group of Glu10 and the amino group of Lys14. These cross-linked amino acid residues are thus closely associated with each other through electrostatic interactions.
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Affiliation(s)
- I Enami
- Department of Biology, Faculty of Science, Science University of Tokyo, Kagurazaka 1-3, Shinjuku-ku, Tokyo 162, Japan.
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