Control of Electron Transport in Photosystem I by the Iron-Sulfur Cluster FX in Response to Intra- and Intersubunit Interactions

Gong, Xiaomin; Agalarov, Rufat; Brettel, Klaus; Carmeli, Chanoch

doi:10.1074/jbc.m301808200

Cited by 24 publications

(27 citation statements)

References 60 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…[11] The flash-induced transient decay, DA, at 820 and 700 nm in PS I proteins isolated from mutants D479C, showed a similar result as for the wild type, with a back reaction of 4.5 ms halftime, which should be ascribed to the reduction of P700 + by the electron-transfer mediator, phenasine methosulfate (see Supporting Information). The results indicated that electrons are mediated to F A /F B in the mutated PS I.…”

Section: By Ludmila Frolov Yossi Rosenwaks Chanoch Carmeli* and Itsupporting

confidence: 61%

Fabrication of a Photoelectronic Device by Direct Chemical Binding of the Photosynthetic Reaction Center Protein to Metal Surfaces

et al. 2005

View full text Add to dashboard Cite

Photosystem I (PS I) is a transmembrane, multi-subunit protein-chlorophyll complex that mediates vectorial, light-induced electron transfer. The nanometer-sized dimensions, an energy yield of approximately 58 %, and the quantum efficiency of almost 1 [1] make the reaction center a promising unit for applications in molecular nanoelectronics. PS I is located in the thylakoid membranes of chloroplasts and cyanobacteria. It mediates light-induced electron transfer from plastocyanin or cytochrome C 553 to ferredoxin. [2,3] The crystalline structure of PS I from Synechococus elongatus and from plants' chloroplast was resolved to 2.5 and 4.4 Å, respectively. [4,5] In cyanobacteria, the complex consists of at least 12 polypeptides, some of which bind 96 light-harvesting chlorophyll molecules. The electron-transport chain contains P700, A 0 , A 1 , F X , F A , and F B , representing a chlorophyll a dimer, a monomeric chlorophyll a, two phylloquinones, and three [4Fe-4S] iron-sulfur centers, respectively. The reaction-center core complex is made up of the heterodimeric PsaA and PsaB subunits, containing the primary electron donor, P700, which undergoes light-induced charge separation and transfers an electron through the sequential carriers A 0 , A 1 , and F X . The final acceptors, F A and F B , are located on another subunit, PsaC. The redox potential of the primary donor, P700, is +0.43 V and that of the final acceptor, F B , is -0.53 V, producing a redox difference of -1.0 V. The charge separation spans about 5 nm of the height of the protein, representing the center-tocenter distance between the primary donor and the final acceptor. The protein complex is 9 nm in height and has a diameter of 21 nm and 15 nm for the trimer and the monomer, respectively.[4] The photoactivity and the nanometer-sized dimensions make this complex a promising unit for applications in molecular nanoelectronics. In earlier works, care was taken to indirectly attach plant PS I [6,7] and bacterial reaction centers [8,9] to solid surfaces in attempts avoid inactivation of selfassembled monolayers.In this work, we devised a system that overcame the problems arising from direct covalent binding of proteins to metal surfaces. We selected the robust PS I reaction centers from the cyanobacteria Synechocystis sp. PCC 6803. The main reason for the structural stability of this PS I is due to the fact that all chlorophyll molecules and carotenoids are integrated into the complex of core subunits, while, in plant and bacterial reaction centers, the antenna chlorophylls are bound to chlorophyll-protein complexes that are attached to the core subunits. Indeed, there was no need to use peptide surfactants, which were essential for stabilization of plant PS I and the bacterial reaction centers. [7] A careful selection of the amino acids, which were modified to cysteines for covalent attachment of the PS I to the gold surface, was the second factor that insured structural and functional stability of the self-assembled, oriented PS I. The rational design was b...

show abstract

Section: By Ludmila Frolov Yossi Rosenwaks Chanoch Carmeli* and Itsupporting

confidence: 61%

Fabrication of a Photoelectronic Device by Direct Chemical Binding of the Photosynthetic Reaction Center Protein to Metal Surfaces

et al. 2005

View full text Add to dashboard Cite

show abstract

“…PCC 6803 was induced by homologous recombination using plasmids pZBL for induction of cysteine Y634C mutations and pBLDB for psaB interruption in recipient cells, as previously described. [4,8,9] PS I was isolated from thylakoid membranes by solubiliztion with ndodecyl b-D-maltoside and purification on DEAE-cellulose columns and on a sucrose gradient. The isolation of PS I, the analysis chlorophyll content and photochemical activity determined by flash-induced transient oxidation of P700 at DA820 and at DA700 nm were as described.…”

Section: Methodsmentioning

confidence: 99%

“…The isolation of PS I, the analysis chlorophyll content and photochemical activity determined by flash-induced transient oxidation of P700 at DA820 and at DA700 nm were as described. [9] In both the cysteine mutant and the native PS I, a half-time of 25 ms for the reduction of P700 was recorded. Surface-exposed cysteines on PS I were probed by biotin-maleimide, as previously described.…”

Section: Methodsmentioning

confidence: 99%

See 1 more Smart Citation

Fabrication of Oriented Multilayers of Photosystem I Proteins on Solid Surfaces by Auto‐Metallization

et al. 2007

View full text Add to dashboard Cite

Fabrication of serially-oriented multilayers of photosynthetic reaction center photosystem I (PS I) was mediated by the photo-catalytic specificity that reduced Pt 4+ ions to metal patches on the reducing side of PSI forming junctions with the oxidizing end of the proteins through Pt-sulfide bond of genetically-engineered cysteine mutants. The dry multilayers can be utilized in hybrid bio-solid-state electronic devices in which an increase in photo-voltage, resulting from the larger absorption cross-section and the serial-arrangement of PS I, is required. PS I is a transmembrane multisubunit protein-chlorophyll complex that mediates vectorial light-induced electron transfer. The nano-size dimension, an absorbed light energy yield of approximately 47% (or ca. 23% of solar radiation) and a photovoltage of 1 V with quantum efficiency of almost 1 [1] , make the reaction center a promising unit for applications in molecular nano-electronics. The robust PS I used in these experiments, that was isolated from the thylakoid membranes of cyanobacteria, is sufficiently stable to be used in hybrid solid-state electronic device. The dry PS I monolayer was shown earlier [3] to remain stable for more than three months and it stayed active for over one year in the present experiments. The structural stability is due to hydrophobic interactions that integrates 96 chlorophyll and 22 carotenoid pigment molecules and the trans membrane helixes of the core subunits.[2]The light-induced electron transfer at cryogenic temperatures [3] is an indication of little structural motions during function. We have fabricated self-assembled oriented monolayers by the formation of direct sulfide bonds between unique cysteine mutants of PS I from the cyanobacteria and the metal surface which generated, a photovoltage of 0.45 V under a dry environment. [4] In earlier works, only indirect adsorption of single plant PS I molecules [5] and binding of bacterial reaction center monolayers [6] were functioning in such an environment. Although a Schottky junction with PS I monolayer provides electronic coupling with unique photovoltaic properties, oriented multilayers can be advantageous when a larger light absorption cross section and enhanced photovoltage values are desired. As an efficient oriented multilayer, the PS I complexes need to be physically and electronically coupled and organized in a serial fashion. The use of the unique specificity of a photo-catalytic protein with redox potential of -0.53 V enabled the reduction of Pt 4+ ions and deposition of metallic platinum at the reducing end of PS I (Fig. 1a and b)

show abstract

“…Deletion mutants of Synechocystis for psbM, psaE, psaK or psaI typically show only limited differences in growth rate or photosynthetic electron transport compared to wild-type lines in replete medium and under low-light irradiance (Bentley et al, 2008;Chitnis et al, 1989a;Naithani et al, 2000;Xu et al, 1995). By contrast, the subunits of photosystem I and II that are typically encoded in chloroplast genomes (such as PsaA, -B, or -C and PsbA) are essential for photosynthesis, as analogous deletion mutants are unable to grow photoautotrophically (Gong et al, 2003;Jansson et al, 1987;Smart et al, 1991). The only significant exception to this is PsaD, a factor involved in binding ferredoxin to photosystem I.…”

Section: Are Certain Types Of Genes Preferentially Transferred?mentioning

confidence: 99%

What makes a chloroplast? Reconstructing the establishment of photosynthetic symbioses

Dorrell¹,

Howe²

2012

Journal of Cell Science

View full text Add to dashboard Cite

SummaryEarth is populated by an extraordinary diversity of photosynthetic eukaryotes. Many eukaryotic lineages contain chloroplasts, obtained through the endosymbiosis of a wide range of photosynthetic prokaryotes or eukaryotes, and a wide variety of otherwise nonphotosynthetic species form transient associations with photosynthetic symbionts. Chloroplast lineages are likely to be derived from preexisting transient symbioses, but it is as yet poorly understood what steps are required for the establishment of permanent chloroplasts from photosynthetic symbionts. In the past decade, several species that contain relatively recently acquired chloroplasts, such as the rhizarian Paulinella chromatophora, and non-photosynthetic taxa that maintain photosynthetic symbionts, such as the sacoglossan sea slug Elysia, the ciliate Myrionecta rubra and the dinoflagellate Dinophysis, have emerged as potential model organisms in the study of chloroplast establishment. In this Commentary, we compare recent molecular insights into the maintenance of chloroplasts and photosynthetic symbionts from these lineages, and others that might represent the early stages of chloroplast establishment. We emphasise the importance in the establishment of chloroplasts of gene transfer events that minimise oxidative stress acting on the symbiont. We conclude by assessing whether chloroplast establishment is facilitated in some lineages by a mosaic of genes, derived from multiple symbiotic associations, encoded in the host nucleus.

show abstract

Control of Electron Transport in Photosystem I by the Iron-Sulfur Cluster FX in Response to Intra- and Intersubunit Interactions

Cited by 24 publications

References 60 publications

Fabrication of a Photoelectronic Device by Direct Chemical Binding of the Photosynthetic Reaction Center Protein to Metal Surfaces

Fabrication of a Photoelectronic Device by Direct Chemical Binding of the Photosynthetic Reaction Center Protein to Metal Surfaces

Fabrication of Oriented Multilayers of Photosystem I Proteins on Solid Surfaces by Auto‐Metallization

What makes a chloroplast? Reconstructing the establishment of photosynthetic symbioses

Contact Info

Product

Resources

About