Photosystem i protein complex. Medical search. Frequent questions

In plants, green algae and cyanobacteria, capable of oxygenic photosynthesis, the central photosynthetic processes of light-induced charge separation are catalysed by two large protein complexes, the photosystems I (PSI) and II (PSII), which are located in the photosynthetic thylakoid membrane. (esrf.fr)
Two protein assemblies in a plant cell's chloroplasts -- Photosystem II (blue and red) and light-harvesting complex II (green and purple) -- are key to initiating photosynthesis. (nersc.gov)
In recent years much photosynthesis research has focused on teasing apart one of these protein assemblies: Photosystem II (PSII). (nersc.gov)
The grana protein organization affects the efficiency of photosynthesis overall," Schneider said. (nersc.gov)
Specifically, NPQ dissipates excessive light excitation energy as heat to prevent the over-excitation and destruction of antenna complexes-chlorophyll-containing, light-responsive structures critical to photosynthesis. (the-scientist.com)
The thylakoid membrane within chloroplasts harbors photosystems - the pigment-protein complexes that carry out the light harvesting and primary electron transport reactions of photosynthesis. (purdue.edu)
Photosystem II (PS II) carries out the formidable water-splitting reaction of photosynthesis and thereby extracts electrons and protons necessary for the anabolic reactions of life. (purdue.edu)
The fluorescence originates from Photosystems I and II (PSI and PSII, respectively) which are protein complexes located inside chloroplasts whose function is to drive the photosynthesis chain. (edinst.com)
Here we show the architecture of the photosystem I reaction center is composed of 11 subunits and identify key components that help explain how the low energy yield from far-red light is efficiently utilized for driving oxygenic photosynthesis. (researchsquare.com)
Photosystems I 1 and II 2 (PSI and PSII, belonging to type I and type II reaction centers, respectively) work sequentially in oxygenic photosynthesis in plants and cyanobacteria 3 . (researchsquare.com)
Photosynthesis - Photosynthesis - The process of photosynthesis: carbon fixation and reduction: The assimilation of carbon into organic compounds is the result of a complex series of enzymatically regulated chemical reactions-the dark reactions. (e-wit.pl)
Briefly describe the overall function of Photosystem II in the light-dependent reactions of photosynthesis. (e-wit.pl)
Details about the flow of electrons through Photosystem II, b6-f complex, Photosystem I and NADP reductase have not been included here but can be found under The Process of Photosynthesis in Plants. (e-wit.pl)

The conversion of light into chemical energy occurs in pigment-protein complexes, the photosystems. (nature.com)
11. Two-photon absorption and excitation spectroscopy of carotenoids, chlorophylls and pigment-protein complexes. (nih.gov)

To understand the regulatory mechanisms underlying the biogenesis of photosystem II (PSII) we have characterized the nuclear mutant hcf136 of Arabidopsis thaliana and isolated the affected gene. (nih.gov)
Biogenesis of photosystem II complexes: transcriptional, translational, and posttranslational regulation. (rupress.org)
The biogenesis and assembly of subunit II of photosystem I (PSI) (psaD gene product) were studied and characterized. (tau.ac.il)

Immunoblot analysis of fractionated chloroplasts showed that the HCF136 protein is a lumenal protein, found only in stromal thylakoid lamellae. (nih.gov)
A chief component of the chloroplasts is the thylakoid membrane, which contains discs of protein assemblies arranged in stacks (grana) that resemble towers of tiny green poker chips. (nersc.gov)

The mutant is devoid of any photosystem II activity, and none of the nuclear- and plastome-encoded subunits of this photosystem accumulate to significant levels. (nih.gov)
Protein labelling studies in the presence of cycloheximide showed that the plastome-encoded PSII subunits are synthesized but are not stable. (nih.gov)
Four Lhca subunits are tightly bound to the photosystem I (PSI) core complex, forming its outer antenna moiety called LHCI. (nature.com)
The Arabidopsis thaliana mutant ΔLhca lacks all Lhca1-4 subunits and compensates for its decreased antenna size by binding LHCII trimers, the main constituent of the photosystem II antenna system, to PSI. (nature.com)
To this extent, we isolated a ΔLhca mutant of A. thaliana which lacks the Lhca1-4 subunits and accumulates PSI core complexes with LHCII bound, analysing plant growth, light-harvesting and excitation energy transfer properties of its PSI complexes compared to wild type. (nature.com)
The initial electron density map of PSI was obtained by multiple isomorphous replacement including effects from anomalous dispersion (MIRAS) and permitted the modelling of the 12 protein subunits of PSI. (esrf.fr)
The 12 protein subunits are in different colours, chlorophylls in yellow, carotenoids in white. (esrf.fr)
Incomplete water-splitting and or inadvertent electron transfer to molecular oxygen generate highly reactive oxygen free radicals that damage key protein subunits in PS II. (purdue.edu)

Electrons are transferred from PSII to PSI via the cytochrome b6f complex (cyt b6f ). (frontiersin.org)
The critical first step is carried out by the photosystem II protein complex, which uses sulight [sic] to split abundant sources of water (H 2 O) into hydrogen, electrons and all the oxygen that sustains our planet," she says. (foresight.org)
The oxygen uptake in the light was investigated in the suspension of isolated pea thylakoids under the conditions of inhibition of electron transport from photosystem II by diuron and delivery of electrons to photosystem I by means of artificial donors in the presence of ascorbate. (tau.ac.il)
We address the fate of electrons downstream of photosystem I when TROL is absent. (nature.com)
In the last steps of this process transfer of energy-conserving electrons beyond photosystem I (PSI) is performed by a small iron-sulphur protein ferredoxin (Fd). (nature.com)
Fd acts simultaneously as a bottleneck and as a hub which distributes high-energy electrons to a multitude of enzymes, which include nitrite reductase, sulphite reductase, fatty acid desaturase, glutamine-2-oxoglutarate amino transferase (GOGAT), redox complexes such as cytochrome b 6 /f for cyclic electron transport (CET) and thioredoxins 2 . (nature.com)
With regard to my internship, I have been availed the unique opportunity to work on my own research project studying a potential rate-limiting step in the transfer of electrons from a protein carrier to its oxidation site at the b 6 f complex. (purdue.edu)
Light energy (indicated by wavy arrows) absorbed by photosystem II causes the formation of high-energy electrons, which are transferred along a series of acceptor molecules in an electron transport chain to photosystem I. Photosystem II obtains … Production of ATP 21. (e-wit.pl)

The crystal structure of PSI shows new types of Mg 2+ axial ligands, not previously observed in the structures of other (bacterio)chlorophyll-protein complexes, the most striking being a phospholipid oxygen and methionine sulphur. (esrf.fr)
PAGE under mildly denaturing and fully denaturing conditions showed that the chl a/b LHC fraction contained chlorophyll-protein complexes CP27, CP29, and CP64. (rupress.org)
He discovered the D2 protein and other chlorophyll-protein complexes related to the photosystem II reaction centre. (royalsociety.org)

These proteins are absent from thylakoids of PS II mutants of algae and vascular plants as a result of either chloroplast or nuclear gene mutations. (rupress.org)
Following insertion into isolated thylakoids, both the precursor and the mature form of subunit II were confined to the PSI complex. (tau.ac.il)
These results suggest that in vivo the precursor of subunit II is inserted and embedded in the thylakoids, as part of the PSI complex. (tau.ac.il)

In this work we have investigated the effect of LHCI/LHCII substitution by comparing the light harvesting and excitation energy transfer efficiency properties of PSI complexes isolated from ΔLhca mutants and from the wild type, as well as the consequences for plant growth. (nature.com)
These are organized into monomers (Lhcb4-6) and trimers (Lhcb1-3, also known as LHCII complexes), with the monomers located in between the core complex and the more peripheral trimers. (nature.com)
Phosphorylation governs the association of the mobile part of the light-harvesting antenna LHCII with either photosystem I or photosystem II. (unige.ch)
Here we identify a phosphatase of Arabidopsis thaliana, called PPH1, which is specifically required for the dephosphorylation of light-harvesting complex II (LHCII). (unige.ch)
Photosynthetic efficiency relies on precise spatial organization of PSII and its associated light-harvesting complex II (LHCII), both of which are concentrated in the grana stacks. (nersc.gov)
To do this they created a nanoscale computational model of LHCII and PSII and used it to analyze the protein organization. (nersc.gov)
Both trimeric light-harvesting complex II (LHCII) and monomeric LHC proteins have been indicated as site(s) of the heat-dissipative reactions. (lu.se)
Here, we report on the construction of a mutant lacking all monomeric LHC proteins but retaining LHCII trimers. (lu.se)
2. Carotenoid-to-chlorophyll energy transfer in recombinant major light-harvesting complex (LHCII) of higher plants. (nih.gov)
3. Energy transfer in light-harvesting complexes LHCII and CP29 of spinach studied with three pulse echo peak shift and transient grating. (nih.gov)

Ultrafast Membrane Protein Dynamics Revealed by X-Ray Scattering with a Femtosecond Free-Electron Laser. (asu.edu)
8. Energy transfer pathways in the minor antenna complex CP29 of photosystem II: a femtosecond study of carotenoid to chlorophyll transfer on mutant and WT complexes. (nih.gov)
19. Femtosecond time-resolved absorption spectroscopy of main-form and high-salt peridinin-chlorophyll a-proteins at low temperatures. (nih.gov)

We also seek to solve the structure of oxidized and reduced CSK proteins using cryo-electron microscopy. (purdue.edu)
Here, we report the structure of the photosystem I reaction center of A. marina determined by cryo-electron microscopy at 2.5 Å resolution. (researchsquare.com)

To do this, they over-expressed in tobacco plants the three main genes controlling NPQ: two encoding the enzymes violaxanthin de-epoxidase and zeaxanthin epoxidase, and one encoding the protein PsbS-a subunit of the photosystem II antenna complex. (the-scientist.com)
LOCUS AF025877 1998 bp DNA PLN 14-OCT-1997 DEFINITION Chlamydomonas reinhardtii photosystem II complex subunit J (psbJ) gene, complete cds. (bio.net)

Complete view of cyanobacterial, trimeric photosystem I from the stromal side of the membrane. (esrf.fr)
It regulates a gene which encodes an abundant chloroplast protein located on the stromal side of the Photosystem I complex. (igem.org)

Under iron-deficient growth conditions, CP43' associates with photosystem I (PSI) to form a complex that consists of a ring of 18 or more CP43' molecules around a PSI trimer, which significantly increases the light-harvesting system of PSI. (wikipedia.org)
In a new study, researchers from Arizona State University (ASU), Deutsches Elektronen-Synchrotron (DESY) and Stanford Linear Accelerator Laboratory (SLAC) describe a simple way to determine the 3-dimensional structures of proteins and other molecules, many of which are inaccessible by existing methods. (foresight.org)
Green plants perform the photooxidation of water molecules within a complex of proteins called Photosystem II, in which manganese-containing enzymes serve as the catalyst. (azooptics.com)
Effects of ascorbate and electron donors on the reduction of the O 2 molecules by the components of acceptor side of photosystem I was analyzed. (tau.ac.il)
Opioid receptors are proteins found on the surface of cells in the nervous and digestive systems that bind opioid proteins, molecules that naturally occur in the body and play a role in regulating pain, pleasure, mood, addiction, and digestion. (nih.gov)

4. Excitation energy transfer in the peridinin-chlorophyll a-protein complex modeled using configuration interaction. (nih.gov)
16. Efficient pathways of excitation energy transfer from delocalized S2 excitons in the peridinin-chlorophyll a-protein complex. (nih.gov)
18. Quantum mechanical analysis of excitation energy transfer couplings in photosystem II. (nih.gov)

These dimers are served by a closely interacting array of Chl a and β-carotene pigments which are bound to plastid-encoded proteins in the so-called core complexes. (nature.com)
The multi-protein complex photosystem II (PS II) harvests photons and transfers their energy through its bound pigments to its reaction center, and ultimately to photosystem I (PSI) through the electron transport chain. (jove.com)
The pigments responsible for caputirng the light energy in photosystems include chlorophyll a , chlorophyll b, and carotenoids. (jove.com)
PSII is a large complex containing dozens of proteins and hundreds of chlorophylls and other pigments," she said. (nersc.gov)
Photosystem is the form of pigments on the thylakoid membrane1. (e-wit.pl)

The ability of plants to adapt to changing light conditions depends on a protein kinase network in the chloroplast that leads to the reversible phosphorylation of key proteins in the photosynthetic membrane. (unige.ch)
Using biochemical and biophysical approaches we investigate the role of protein phosphorylation and oxidative protein modification in PS II disassembly. (purdue.edu)

The linear electron transport begins with water splitting at the level of photosystem II (PSII) and ends at photosystem I (PSI) with the reduction of NADP + by ferredoxin. (frontiersin.org)
b) manganese complexes can serve as suitable electron donors for light-induced NADP+ reduction catalyzed by D 1/D 2/cytochrome b 559 complexes and ferredoxin plus ferredoxin-NADP+ reductase under anaerobic conditions and c) the specific turnover rate of the system leading to NADP+ reduction is extremely, small. (elsevierpure.com)

These are connected in series by a cytochrome b6f complex for a linear electron transport from water to NADP+, producing ATP and NADPH. (purdue.edu)

Photosystem II light-harvesting proteins are the intrinsic transmembrane proteins CP43 (PsbC) and CP47 (PsbB) occurring in the reaction centre of photosystem II (PSII). (wikipedia.org)

Plants, algae and some bacteria use two photosystems, PSI with P700 and PSII with P680. (wikipedia.org)
P680 and P700 are the chlorophyll centres in photosystems I and II, respectively. (edinst.com)

This family also includes the iron-stress induced chlorophyll-binding protein CP43', encoded by the IsiA gene, which evolved in cyanobacteria from a PSII protein to cope with light limitations and stress conditions. (wikipedia.org)
LOCUS CRU68060 4307 bp DNA PLN 09-OCT-1997 DEFINITION Chlamydomonas reinhardtii actin-related protein (ACT2) gene, complete cds. (bio.net)

It is a high constitutive expression promoter that encodes for a ferrodoxin-binding protein of photosystem I. This pSAD promoter was submitted in 2014 by the Concordia team (BBa_K1547005). (igem.org)

PPH1, which belongs to the family of monomeric PP2C type phosphatases, is a chloroplast protein and is mainly associated with the stroma lamellae of the thylakoid membranes. (unige.ch)
Chlorophyll a/b light-harvesting complexes (chl a/b LHC) and photosystem II (PSII) cores were isolated from an octyl glucoside-containing sucrose gradient after solubilization of barley thylakoid membranes with Triton X-100 and octyl glucoside. (rupress.org)
FNR is recruited to thylakoid membranes via integral membrane thylakoid rhodanase-like protein TROL. (nature.com)

It uses light energy derived from LIGHT-HARVESTING PROTEIN COMPLEXES to drive electron transfer reactions that result in either the reduction of NADP to NADPH or the transport of PROTONS across the membrane. (bvsalud.org)

and far-right panel, green fluorescence from CRR1-GFP fusion protein. (purdue.edu)
1 At room temperature the main contribution to fluorescence comes from PSII, the most widely studied photosystem. (edinst.com)
13. Stepwise two-photon excited fluorescence from higher excited states of chlorophylls in photosynthetic antenna complexes. (nih.gov)
14. Monitoring fluorescence of individual chromophores in peridinin-chlorophyll-protein complex using single molecule spectroscopy. (nih.gov)
15. Carotenoid-chlorophyll coupling and fluorescence quenching in aggregated minor PSII proteins CP24 and CP29. (nih.gov)

Dr. Brian Kobilka, a grantee of the Common Fund Structural Biology program, has been awarded the Nobel Prize in Chemistry along with Dr. Robert Lefkowitz for their groundbreaking studies of G-protein coupled receptors (GPCRs). (nih.gov)
A major goal of the Structural Biology program is to determine the unique three-dimensional structure of membrane proteins such as GPCRs, in order to inform the design of therapeutics that specifically fit inside the target protein, thereby improving drug efficacy and reducing side effects. (nih.gov)
Structural Biology researchers publish methods and tools to aid in protein structure determination! (nih.gov)
The Structural Biology Program has published a special METHODS (link is external) issue on "Membrane Protein Technologies for Structural Biology. (nih.gov)
Membrane Protein Technologies for Structural Biology. (nih.gov)

Nature's Way Chlorofresh is a liquid chlorophyllin complex that supports antioxidant pathways and detoxification processes and helps neutralize free. (johnharvards.com)
5. Effect of protein matrix on CP29 spectra and energy transfer pathways. (nih.gov)
Quantitative proteomics and a newly developed proteomic profiling technique that identifies low abundance proteins were employed to examine the full complement of expressed proteins and consequently the metabolic pathways utilized by the diatom under the two Fe conditions. (nih.gov)
Given sufficient time to acclimate to Fe limitation, T. pseudonana up-regulates proteins involved in pathways associated with intracellular protein recycling, thereby decreasing dependence on extracellular nitrogen (N), C and Fe. (nih.gov)

9. Spectroscopic study of the light-harvesting CP29 antenna complex of photosystem II--part I. (nih.gov)
20. Towards a structure-based exciton Hamiltonian for the CP29 antenna of photosystem II. (nih.gov)

Reconstitution of light-harvesting complexes and photosystem II cores into galactolipid and phospholipid liposomes. (rupress.org)
Freeze-fracture electron microscopy of the chl a/b LHC after reconstitution into digalactosyldiglyceride (DG) or phosphatidylcholine (PC) vesicles showed that the protein particles (approximately 7.5 +/- 1.6 nm) were approximately 99 and 90% randomly dispersed, respectively, in the liposomes. (rupress.org)

The new approach taken by the Japanese researchers cleverly connects photosystem I (PSI) from the blue-green algae Thermosynechococcus elongatus with a synthetic apparatus. (sciencedaily.com)
There are two types of photosystems in plants and algae. (purdue.edu)
One such mystery is how Photosystem II, a protein complex in plants, algae and cyanobacteria, harvests energy from sunlight and uses it to split water, producing the oxygen we breathe. (lightsources.org)
Overall, the lab focuses on elucidating the structure and function of the cytochrome b 6 f complex-an integral membrane protein that mediates electron flow between photosystem II and photosystem I in order to establish a proton gradient to be used for the synthesis of ATP in photosynthetic plants, bacteria and algae. (purdue.edu)

A large multisubunit protein complex that is found in the THYLAKOID MEMBRANE . (bvsalud.org)

The capability of different manganese complexes to act as PS II electron donors in D 1/D2/ cytochrome b559 complexes has been analyzed by measuring actinic light-induced absorption changes at 680 nm (650 nm) and 340 nm, reflecting the photoaccumulation of Pheophytin - (Pheo-) and the reduction of NADP+, respectively. (elsevierpure.com)

Photosystem II protein PsbC InterPro: IPR005869 Light-harvesting complex Barber J (August 2002). (wikipedia.org)
The HCF136 protein is produced already in dark-grown seedlings and its levels do not increase dramatically during light-induced greening. (nih.gov)
Light-harvesting complexes (LHCs) are major constituents of the antenna systems in higher plant photosystems. (nature.com)
In eukaryotic photosynthetic organisms, two photosystems, namely PSI) and PSII, undergo light-driven charge separation. (nature.com)
Light dependent reactions consist of photosystem II and I. Each of these separate reactions processes the inputs of the reaction one by one, generating the products. (fountainmagazine.com)
These two proteins emerge as key players in the adaptation of the photosynthetic apparatus to changes in light quality and quantity. (unige.ch)
It uses light energy derived from LIGHT-HARVESTING PROTEIN COMPLEXES to catalyze the splitting of WATER into DIOXYGEN and of reducing equivalents of HYDROGEN . (nih.gov)
GPCRs are proteins located in cell membranes that transmit important information about the environment outside the cell, including light, smell, taste, hormone levels, and neurotransmitters. (nih.gov)
Reaction Center Photosystem I Reaction Center Light Light Materials made and used 6CO 2 + 6H 2 O + sunlight g C 6 H 12 O 6 + 6O 2 Reactants used in Photosystem II: Products made in Photosystem II: Reactants used in Photosystem I: Products made in Photosystem I: The photosystems would not function properly if _____ was not available. (e-wit.pl)

To resolve the molecular basis for the concurrent absence of the PS II polypeptides, protein synthesis rates and mRNA levels were measured in mutants of Chlamydomonas reinhardtii that lack PS II. (rupress.org)

Cofactors of the antenna system (chlorophylls green, ring substituents omitted for clarity, carotenoids yellow) and of the electron transfer chain (blue and Fe4S4 cluster as yellow and blue spheres) in one monomer of photosystem I. (esrf.fr)

This transition balances excitation energy pressure between the photosystems, restoring the plastoquinone/PQH 2 ratio. (nature.com)
Our recent research reveals CSK to be an iron-sulfur protein, containing a [3Fe-4S] cluster with which it perceives the redox state of the photosynthetic electron carrier plastoquinone (PQ). (purdue.edu)

this fact was interpreted as a consequence of the increase in the apparent rate constant of the reaction of the O 2 reduction by components of acceptor side of photosystem I. (tau.ac.il)

The chosen target of the new study is a critical enzyme known as photosystem II. (foresight.org)

The recent crystal structure of photosystem I (PSI) from Thermosynechococcus elongatus shows two nearly symmetric branches of electron transfer cofactors including the primary electron donor, P 700 , and a sequence of electron acceptors, A, A 0 and A 1 , bound to the PsaA and PsaB heterodimer. (elsevierpure.com)

Over-reduction of PET chain can damage protein complexes and result in production of the excess amounts of reactive oxygen species (ROS) 6 . (nature.com)

Product of Photosystem II Reactant of The Calvin Cycle (Dark Reactions) Oxygen (O2) Product of Photosystem II. (e-wit.pl)

We conclude that non-photochemical quenching is catalysed by two independent mechanisms, with the fastest activated response catalysed within monomeric LHC proteins depending on both zeaxanthin and lutein and on the formation of a radical cation. (lu.se)

Anatomy5

Organisms16

Chemicals and Drugs43

Analytical, Diagnostic and Therapeutic Techniques and Equipment10

Phenomena and Processes21

Disciplines and Occupations1

Technology, Industry, Agriculture3

Information Science3

Health Care1

Photosynthesis13

Pigment-protein complexes2

Biogenesis3

Chloroplasts2

Subunits8

Electrons8

Chlorophyll-protein complexes3

Thylakoids3

LHCII10

Femtosecond3

Cryo-electron m2

Subunit2

Stromal2

Molecules5

Excitation energy transfer3

Pigments5

Phosphorylation2

Ferredoxin2

Cytochrome b6f co1

Reaction centre1

P6802

Gene2

PsaD1

Thylakoid membranes3

NADP1

Fluorescence5

Structural Biology5

Pathways4

CP292

Reconstitution2

Algae4

Multisubunit1

Electron donors1

Light9

Chlamydomonas1

Chlorophylls1

Plastoquinone2

Acceptor1

Enzyme1

Elongatus1

Reduction1

Reactions1

Monomeric1