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Boon Leong Lim - One of the best experts on this subject based on the ideXlab platform.
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fdc1 and leaf type Ferredoxins channel electrons from photosystem i to different downstream electron acceptors
Frontiers in Plant Science, 2018Co-Authors: Xiaoqian Guan, Shuai Chen, Chia Pao Voon, Kambo Wong, Mikko Tikkanen, Boon Leong LimAbstract:Plant-type Ferredoxins in Arabidopsis transfer electrons from the photosystem I to multiple redox-driven enzymes involved in the assimilation of carbon, nitrogen, and sulfur. Leaf-type Ferredoxins also modulate the switch between the linear and cyclic electron routes of the photosystems. Recently, two novel ferredoxin homologs with extra C-termini were identified in the Arabidopsis genome (AtFdC1, At4g14890; AtFdC2, At1g32550). FdC1 was considered as an alternative electron acceptor of PSI under extreme ferredoxin-deficient conditions. Here, we showed that FdC1 could interact with some, but not all, electron acceptors of leaf-type Fds, including the ferredoxin-thioredoxin reductase, sulfite reductase, and nitrite reductase. Photoreduction assay on cytochrome c and enzyme assays confirmed its capability to receive electrons from PSI and donate electrons to the Fd-dependent sulfite reductase and nitrite reductase but not to the ferredoxin-NADP+ oxidoreductase. Hence, FdC1 and leaf-type Fds may play differential roles by channeling electrons from photosystem I to different downstream electron acceptors in photosynthetic tissues. In addition, the median redox potential of FdC1 may allow it to receive electrons from FNR in non-photosynthetic plastids.
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2018Co-Authors: Xiaoqian Guan, Shuai Chen, Chia Pao Voon, Kambo Wong, Mikko Tikkanen, Boon Leong LimAbstract:Plant-type Ferredoxins in Arabidopsis transfer electrons from the photosystem I to multiple redox-driven enzymes involved in the assimilation of carbon, nitrogen, and sulfur. Leaf-type Ferredoxins also modulate the switch between the linear and cyclic electron routes of the photosystems. Recently, two novel ferredoxin homologs with extra C-termini were identified in the Arabidopsis genome (AtFdC1, AT4G14890; AtFdC2, AT1G32550). FdC1 was considered as an alternative electron acceptor of PSI under extreme ferredoxin-deficient conditions. Here, we showed that FdC1 could interact with some, but not all, electron acceptors of leaf-type Fds, including the ferredoxin-thioredoxin reductase (FTR), sulfite reductase (SiR), and nitrite reductase (NiR). Photoreduction assay on cytochrome c and enzyme assays confirmed its capability to receive electrons from PSI and donate electrons to the Fd-dependent SiR and NiR but not to the ferredoxin-NADP+ oxidoreductase (FNR). Hence, FdC1 and leaf-type Fds may play differential roles by channeling electrons from photosystem I to different downstream electron acceptors in photosynthetic tissues. In addition, the median redox potential of FdC1 may allow it to receive electrons from FNR in non-photosynthetic plastids.
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2018Co-Authors: Xiaoqian Guan, Shuai Chen, Chia Pao Voon, Kambo Wong, Mikko Tikkanen, Boon Leong LimAbstract:Plant-type Ferredoxins in Arabidopsis transfer electrons from the photosystem I to multiple redox-driven enzymes involved in the assimilation of carbon, nitrogen, and sulfur. Leaf-type Ferredoxins also modulate the switch between the linear and cyclic electron routes of the photosystems. Recently, two novel ferredoxin homologs with extra C-termini were identified in the Arabidopsis genome (AtFdC1, AT4G14890; AtFdC2, AT1G32550). FdC1 was considered as an alternative electron acceptor of PSI under extreme ferredoxin-deficient conditions. Here, we showed that FdC1 could interact with some, but not all, electron acceptors of leaf-type Fds, including the ferredoxin-thioredoxin reductase (FTR), sulfite reductase (SiR), and nitrite reductase (NiR). Photoreduction assay on cytochrome c and enzyme assays confirmed its capability to receive electrons from PSI and donate electrons to the Fd-dependent SiR and NiR but not to the ferredoxin-NADP+ oxidoreductase (FNR). Hence, FdC1 and leaf-type Fds may play differential roles by channeling electrons from photosystem I to different downstream electron acceptors in photosynthetic tissues. In addition, the median redox potential of FdC1 may allow it to receive electrons from FNR in non-photosynthetic plastids.
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FdC1 and Leaf-Type Ferredoxins Channel Electrons From Photosystem I to Different Downstream Electron Acceptors
Frontiers Media S.A., 2018Co-Authors: Xiaoqian Guan, Shuai Chen, Chia Pao Voon, Kambo Wong, Mikko Tikkanen, Boon Leong LimAbstract:Plant-type Ferredoxins in Arabidopsis transfer electrons from the photosystem I to multiple redox-driven enzymes involved in the assimilation of carbon, nitrogen, and sulfur. Leaf-type Ferredoxins also modulate the switch between the linear and cyclic electron routes of the photosystems. Recently, two novel ferredoxin homologs with extra C-termini were identified in the Arabidopsis genome (AtFdC1, AT4G14890; AtFdC2, AT1G32550). FdC1 was considered as an alternative electron acceptor of PSI under extreme ferredoxin-deficient conditions. Here, we showed that FdC1 could interact with some, but not all, electron acceptors of leaf-type Fds, including the ferredoxin-thioredoxin reductase (FTR), sulfite reductase (SiR), and nitrite reductase (NiR). Photoreduction assay on cytochrome c and enzyme assays confirmed its capability to receive electrons from PSI and donate electrons to the Fd-dependent SiR and NiR but not to the ferredoxin-NADP+ oxidoreductase (FNR). Hence, FdC1 and leaf-type Fds may play differential roles by channeling electrons from photosystem I to different downstream electron acceptors in photosynthetic tissues. In addition, the median redox potential of FdC1 may allow it to receive electrons from FNR in non-photosynthetic plastids
Tairo Oshima - One of the best experts on this subject based on the ideXlab platform.
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Ferredoxin and related enzymes from Sulfolobus.
Methods in Enzymology, 2004Co-Authors: Toshio Iwasaki, Tairo OshimaAbstract:Publisher Summary One of the characteristic features in the central metabolic pathways of both anaerobic and aerobic archaea is the involvement in electron transport of Ferredoxins. Ferredoxins are simple iron-sulfur proteins with prosthetic groups composed of iron and sulfur atoms and function as intracellular electron carders. The physiological significance of bacterial-type Ferredoxins in several aerobic and thermoacidophilic archaea, such as Sulfolobus and Thermoplasma, was first recognized by Kerscher et al ., when it was demonstrated that Ferredoxins are an effective electron acceptor of a coenzyme A-acylating 2-oxoacid:ferredoxin oxidoreductase. The most unusual feature of these Ferredoxins is the presence of an isolated zinc center, and hence they are called the “zinc-containing Ferredoxins.” This chapter focuses on purification and some structural and functional properties of archaeal zinc-containing Ferredoxins and several related metalloproteins: 2-oxoacid: ferredoxin oxidoreductase, red iron-sulfur flavoprotein, and sulredoxin.
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structural conservation of the isolated zinc site in archaeal zinc containing Ferredoxins as revealed by x ray absorption spectroscopic analysis and its evolutionary implications
Journal of Biological Chemistry, 1999Co-Authors: Nathaniel J Cosper, Tairo Oshima, Christina Stalhandske, Hideo Iwasaki, Robert A Scott, Toshio IwasakiAbstract:Abstract The zfx gene encoding a zinc-containing ferredoxin from Thermoplasma acidophilumstrain HO-62 was cloned and sequenced. It is located upstream of two genes encoding an archaeal homolog of nascent polypeptide-associated complex α subunit and a tRNA nucleotidyltransferase. This gene organization is not conserved in several euryarchaeoteal genomes. The multiple sequence alignments of the zfx gene product suggest significant sequence similarity of the ferredoxin core fold to that of a low potential 8Fe-containing dicluster ferredoxin without a zinc center. The tightly bound zinc site of zinc-containing Ferredoxins from two phylogenetically distantly related Archaea, T. acidophilum HO-62 and Sulfolobus sp. strain 7, was further investigated by x-ray absorption spectroscopy. The zinc K-edge x-ray absorption spectra of both archaeal Ferredoxins are strikingly similar, demonstrating that the same zinc site is found in T. acidophilum ferredoxin as in Sulfolobus sp. ferredoxin, which suggests the structural conservation of isolated zinc binding sites among archaeal zinc-containing Ferredoxins. The sequence and spectroscopic data provide the common structural features of the archaeal zinc-containing ferredoxin family.
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novel zinc binding centre in thermoacidophilic archaeal Ferredoxins
Nature Structural & Molecular Biology, 1996Co-Authors: Tomomi Fujii, Nobuo Tanaka, Tairo Oshima, Yasuo Hata, Takayoshi WakagiAbstract:The crystal structure of ferredoxin from Sulfolobus species strain 7 reveals a novel zinc-binding centre that may play an important role in stabilizing the protein and may be common to thermoacidophilic archaeal Ferredoxins.
Hiroshi Matsubara - One of the best experts on this subject based on the ideXlab platform.
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tertiary structure of 2fe 2s ferredoxin from spirulina platensis refined at 2 5 a resolution structural comparisons of plant type Ferredoxins and an electrostatic potential analysis
Journal of Biochemistry, 1995Co-Authors: Keiichi Fukuyama, Tomitake Tsukihara, Noritaka Ueki, Haruki Nakamura, Hiroshi MatsubaraAbstract:The structure of plant-type [2Fe-2S] ferredoxin isolated from Spirulina platensis has been refined using diffraction data to 2.5 A resolution by alternate cycles of simulated annealing and manual revision of the model. The final R factor is 19.9% for 2,912 reflections with F > 2 sigma F between 8.0 and 2.5 A resolution. S. platensis ferredoxin, like other plant-type [2Fe-2S] Ferredoxins, has a major alpha-helix flanking a sheet consisting of four beta strands. The present refinement revises the conformation of residues 56-71, in which a one-turn helix was identified. Superposition of the Spirulina ferredoxin structure on the structures of other Ferredoxins that have been well refined showed structural perturbation at a few residues on the amino and carboxyl termini and the turn between the first and second beta-strands. The root-mean-square deviations of the corresponding C alpha atoms of the pairs of Ferredoxins range from 0.90 to 1.17 A for all the residues, but from 0.64 to 0.70 A if the few perturbed residues are excluded. Therefore, it may be concluded that the main-chain foldings of all the plant-type [2Fe-2S] Ferredoxins are essentially the same. Electrostatic potential analysis showed that the molecular surface around the cluster is negatively charged, whereas that of the beta-sheet of the other side is positively charged. The interaction between ferredoxin and ferredoxin-NADP+ reductase is discussed on the basis of the charge distributions of these molecules and biochemical data.
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genetic analysis of functional differences among distinct Ferredoxins in rhodobacter capsulatus
Journal of Biological Chemistry, 1991Co-Authors: Kazuhiko Saeki, Yumi Suetsugu, Kenichiro Tokuda, Y Miyatake, D A Young, B L Marrs, Hiroshi MatsubaraAbstract:Rhodobacter capsulatus has been known to possess two Ferredoxins (I and II) with distinct physicochemical and structural properties: ferredoxin I is a 2[4Fe-4S] type and the other is a [3Fe-4S] [4Fe-4S] type. To analyze their possible functional differences, their genes (fdxN and fdxA) were cloned, sequenced, and subjected to interposon mutagenesis experiments. The former gene was adjacent to a gene encoding a chloroplast-type [2Fe-2S] ferredoxin (fdxC). Mutants with inactivated fdxN and/or fdxC were obtained, and they showed virtually no growth under nitrogen-fixing conditions. Complementation experiments confirmed that both fdxN and fdxC were required for nitrogen fixation. On the other hand, we have not been able to disrupt fdxA under the screening conditions surveyed, including conditions that do not require nitrogenase activity for growth, suggesting that ferredoxin II could have an unknown essential role(s). These indicate functional differences among multiple Ferredoxins in one bacterium other than in cyanobacterial heterocysts and indispensability of certain Ferredoxins in nitrogen fixation other than Rhizobium meliloti FdxN.
Michel Roth - One of the best experts on this subject based on the ideXlab platform.
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Crystal structure of the ferredoxin I from Desulfovibrio africanus at 2.3 A resolution.
Biochemistry, 1994Co-Authors: Anne Sery, Claude E. Hatchikian, Dominique Housset, Laurence Serre, J. Bonicel, Michel Frey, Michel RothAbstract:The crystal structure of the ferredoxin I from the sulfate-reducing bacterium Desulfovibrio africanus (DaFdI) has been solved and refined by X-ray diffraction. The crystals are orthorhombic with a = 96.6 A, b = 58.1 A, and c = 20.7 A, space group P2(1)2(1)2, and two ferredoxin molecules per asymmetric unit. The initial electron density map has been obtained by combining phasing by molecular replacement methods, anomalous scattering, and noncrystallographic averaging. The final crystallographic R factor is 0.182 with 10-2.3 A resolution data. In parallel, the amino acid sequence was redetermined. This showed that DaFdI contains 64 residues (instead of 61) including one free cysteine, one histidine, and one tryptophan in the C-terminal part of the molecule. The current molecular model includes the two molecules of the asymmetric unit, 67 water molecules, and one sulfate ion. The DaFdI overall folding very closely resembles that of Ferredoxins of known structure. Comparisons with the single cluster Ferredoxins from Desulfovibrio gigas and Bacillus thermoproteolyticus show that the presence or the absence of a disulfide bridge does not significantly affect the folding of the other half of the molecule, including the characteristic alpha-helix of the single cluster ferreddoxins. Like other Ferredoxins or analogs, the [4Fe-4S] iron--sulfur cluster presents, at 2.3 A resolution, a cubane-like geometry. By contrast, its immediate environment is different as it includes, besides the four cysteic sulfur ligands, the sulfur atom of the free cysteine. This sulfur atom, which is buried within the protein, is in van der Waals contact with one labile sulfur of the cluster and one liganded cysteic sulfur. The association of a [4Fe-4S] cluster with one free cysteic sulfur is similar to that previously found in both X-ray structures of Azotobacter vinelandii and Peptococcus aerogenes [Stout, C. D. (1989) J. Mol. Biol. 205, 545-555; Backes, G., et al. (1991) J. Am. Chem. Soc. 113, 2055-2064]. Chemical sequence analysis suggests that this characteristic [4Fe-4S] cluster sulfur environment is widely distributed among Ferredoxins.
Jatindra N Tripathy - One of the best experts on this subject based on the ideXlab platform.
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an alternative plant like cyanobacterial ferredoxin with unprecedented structural and functional properties
Biochimica et Biophysica Acta, 2019Co-Authors: Taiki Motomura, Pierre Setif, Lidia Zuccarello, Alain Boussac, Yasufumi Umena, David Lemaire, Jatindra N Tripathy, Miwa Sugiura, Rainer HienerwadelAbstract:Abstract Photosynthetic [2Fe-2S] plant-type Ferredoxins have a central role in electron transfer between the photosynthetic chain and various metabolic pathways. Several genes are coding for [2Fe 2S] Ferredoxins in cyanobacteria, with four in the thermophilic cyanobacterium Thermosynechococcus elongatus. The structure and functional properties of the major ferredoxin Fd1 are well known but data on the other Ferredoxins are scarce. We report the structural and functional properties of a novel minor type ferredoxin, Fd2 of T. elongatus, homologous to Fed4 from Synechocystis sp. PCC 6803. Remarkably, the midpoint potential of Fd2, Em = −440 mV, is lower than that of Fd1, Em = −372 mV. However, while Fd2 can efficiently react with photosystem I or nitrite reductase, time-resolved spectroscopy shows that Fd2 has a very low capacity to reduce ferredoxin-NADP+ oxidoreductase (FNR). These unique Fd2 properties are discussed in relation with its structure, solved at 1.38 A resolution. The Fd2 structure significantly differs from other known Ferredoxins structures in loop 2, N-terminal region, hydrogen bonding networks and surface charge distributions. UV–Vis, EPR, and Mid- and Far-IR data also show that the electronic properties of the [2Fe 2S] cluster of Fd2 and its interaction with the protein differ from those of Fd1 both in the oxidized and reduced states. The structural analysis allows to propose that valine in the motif Cys53ValAsnCys56 of Fd2 and the specific orientation of Phe72, explain the electron transfer properties of Fd2. Strikingly, the nature of these residues correlates with different phylogenetic groups of cyanobacterial Fds. With its low redox potential and its discrimination against FNR, Fd2 exhibits a unique capacity to direct efficiently photosynthetic electrons to metabolic pathways not dependent on FNR.
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An alternative plant-like cyanobacterial ferredoxin with unprecedented structural and functional properties: Ferredoxin with low Em discriminating against FNR
Biochimica biophysica acta (BBA) - Bioenergetics, 2019Co-Authors: Taiki Motomura, Pierre Setif, Lidia Zuccarello, Alain Boussac, Yasufumi Umena, David Lemaire, Jatindra N Tripathy, Miwa Sugiura, Rainer Hienerwadel, Jian-ren ShenAbstract:Photosynthetic [2Fe-2S] plant-type Ferredoxins have a central role in electron transfer between the photosynthetic chain and various metabolic pathways. Several genes are coding for [2Fe2S] Ferredoxins in cyanobacteria, with four in the thermophilic cyanobacterium Thermosynechococcus elongatus. The structure and functional properties of the major ferredoxin Fd1 are well known but data on the other Ferredoxins are scarce. We report the structural and functional properties of a novel minor type ferredoxin, Fd2 of T. elongatus, homologous to Fed4 from Synechocystis sp. PCC 6803. Remarkably, the midpoint potential of Fd2, Em = -440 mV, is lower than that of Fd1, Em = -372 mV. However, while Fd2 can efficiently react with photosystem I or nitrite reductase, time-resolved spectroscopy shows that Fd2 has a very low capacity to reduce ferredoxin-NADP+ oxidoreductase (FNR). These unique Fd2 properties are discussed in relation with its structure, solved at 1.38 Å resolution. The Fd2 structure significantly differs from other known Ferredoxins structures in loop 2, N-terminal region, hydrogen bonding networks and surface charge distributions. UV-Vis, EPR, and Mid- and Far-IR data also show that the electronic properties of the [2Fe2S] cluster of Fd2 and its interaction with the protein differ from those of Fd1 both in the oxidized and reduced states. The structural analysis allows to propose that valine in the motif Cys53ValAsnCys56 of Fd2 and the specific orientation of Phe72, explain the electron transfer properties of Fd2. Strikingly, the nature of these residues correlates with different phylogenetic groups of cyanobacterial Fds. With its low redox potential and its discrimination against FNR, Fd2 exhibits a unique capacity to direct efficiently photosynthetic electrons to metabolic pathways not dependent on FNR.
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pattern of expression and substrate specificity of chloroplast Ferredoxins from chlamydomonas reinhardtii
Journal of Biological Chemistry, 2009Co-Authors: Aimee M Terauchi, Toshiharu Hase, Jatindra N Tripathy, Mirko Zaffagnini, Shane Tappa, Masakazu Hirasawa, David B Knaff, Patrick J Farmer, Stephane D Lemaire, Sabeeha S MerchantAbstract:Ferredoxin (Fd) is the major iron-containing protein in photosynthetic organisms and is central to reductive metabolism in the chloroplast. The Chlamydomonas reinhardtii genome encodes six plant type [Fe2S2] Ferredoxins, products of PETF, FDX2–FDX6. We performed the functional analysis of these Ferredoxins by localizing Fd, Fdx2, Fdx3, and Fdx6 to the chloroplast by using isoform-specific antibodies and monitoring the pattern of gene expression by iron and copper nutrition, nitrogen source, and hydrogen peroxide stress. In addition, we also measured the midpoint redox potentials of Fd and Fdx2 and determined the kinetic parameters of their reactions with several ferredoxin-interacting proteins, namely nitrite reductase, Fd:NADP+ oxidoreductase, and Fd:thioredoxin reductase. We found that each of the FDX genes is differently regulated in response to changes in nutrient supply. Moreover, we show that Fdx2 (Em = −321 mV), whose expression is regulated by nitrate, is a more efficient electron donor to nitrite reductase relative to Fd. Overall, the results suggest that each ferredoxin isoform has substrate specificity and that the presence of multiple ferredoxin isoforms allows for the allocation of reducing power to specific metabolic pathways in the chloroplast under various growth conditions.