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Photosystem I

Structural and functional organization of the FSI complex (CCI not shown): P700 (P 700 ) - a special pair; A 0 is chlorophyll a 695 ; A 1 is phylloquinone; F x , F a , F b - iron-sulfur clusters (the figure does not show a pair of additional chlorophylls a).

Photosystem I (the first photosystem , photosystem one , PSI), or plastocyanine-ferredoxine-oxidoreductase is the second functional complex of the electron transport chain ( ETC ) of chloroplasts . It receives an electron from plastocyanin and, absorbing light energy , forms a strong P 700 reducing agent, capable of reducing NADP + through a chain of electron carriers. Thus, with the participation of PSI, an electron source ( NADPH ) is synthesized for subsequent carbon reduction reactions in chloroplasts in the Calvin cycle . In addition, PSI can carry out cyclic electron transport coupled with ATP synthesis, providing additional ATP synthesis in chloroplasts [1] .

Discovery History

Non-cyclic electron transport begins with the fact that the manganese cluster of photosystem II oxidizes water , restoring the pool of plastoquinones . Next, the cytochrome b 6 f complex oxidizes plastoquinones, and the electron is transferred through plastocyanin to photosystem I, where it is used for the synthesis of NADPH . The violation of the formal logic in the names of photosystems is due to the fact that photosystem I was discovered earlier than photosystem II .

The first data indicating the existence of PSI appeared in the 1950s, but at that time no one could still appreciate the significance of these discoveries [2] . The idea of ​​the existence of two photosystems in chloroplasts arose already in the 1940s on the basis of experiments by R. Emerson's laboratory, which discovered the effect of a decrease in the quantum yield of photosynthesis when chloroplasts were illuminated with monochromatic red light (λ> 680 nm), which excites only PSI, and the quantum gain effect output when adding backlight with a wavelength of about 650 nm, which excited PSII (the so-called Emerson effect ). We should also mention the light-induced EPR signal discovered by Komonner in 1956, which was called signal I. By pure chance, signal I and signal II came from PSI and PSII, respectively [2] . Only in 1960, Louis Duisens proposed the concept of photosystem I and photosystem II, and in the same year, Fay Bendall and Robert Hill organized the results of previous discoveries in the coherent theory of sequential photosynthesis reactions [2] . The hypothesis of Hill and Bendall was later confirmed in the experiments of Duensens and Witt in 1961 [2] .

After this, systematic attempts began to physically isolate photosystem I, to determine its three-dimensional structure and fine structure. In 1966, a boom in research in this area began: Anderson and Bordman subjected the chloroplast membranes to ultrasound followed by digitonin treatment, Vernon used X-100 Triton , and Ogawa used dodecyl sulfate . However, the first extracts obtained contained impurities of light-collecting complexes, as well as cytochromes f and b 6 . It took a long time to figure out that the extracts obtained were a mixture [2] .

In 1968, Reed and Clayton were able to isolate the reaction center of photosystem I from purple bacteria , which greatly spurred the study of oxygenic photosynthesis. However, the question remained open: which of the selected was the true reaction center, what were the antenna complexes, and what were the additional subunits. For a long time, the efficient isolation of the reaction center of photosystem I remained an unresolved problem. In the end, it turned out that it was easiest to do this for cyanobacteria , since they did not have external antennas integrated into the membrane. After numerous attempts with different species, it turned out that the most promising species in this regard are representatives of Synechocystis and Synechococcus , since photosystem I isolated from Thermosynechococcus elongatus gave a very stable reaction center suitable for crystallization and X-ray diffraction studies [2] .

Differences from photosystem II

The main function of photosystem II is the generation of a strong oxidizing agent, which initiates the oxidation of water and the transfer of its electrons to the membrane carrier. The main function of photosystem I is to saturate these low - level electrons with energy in order to restore NADP + using them. Since the energy of the overall process is too large to be carried out within the framework of one reaction center , two photosystems appeared in the course of evolution that separately carry out different parts of this reaction. Their specific functions determine the features of their structure. So, photosystem I is symmetrical, that is, two branches of electron transport work in it, which makes it much faster, while photosystem II is asymmetric and has only one working branch, which slows down the transport of electrons, but makes it more controllable. Both photosystems differ significantly in the structure of antennas, additional subunits, methods of regulation, and their position in the membrane [3] . So, photosystem I has an integrated antenna, the chlorophylls of which are located directly on the main proteins of the complex — A and B, while in photosystem II they are carried out on the outer proteins CP47 and CP43. In the number of additional small regulatory subunits, PS II significantly exceeds PS I, which is associated with the need for fine regulation of the process of water oxidation, which is potentially extremely dangerous for the cell. This also explains the heterogeneous distribution of photosystems in the thylakoid membrane : while PS I is located mainly in the marginal, end and stromal membranes, PS II is almost completely in the region of paired membranes, which provides the cell with additional protection against the active oxygen species produced by it [4 ] .

The main difference between photosystem II and photosystem I is the presence of a large lumen-facing domain that contains a manganese cluster and the protective proteins surrounding it. It is here that the process of photochemical oxidation of water occurs, accompanied by the release of oxygen and protons [3] .

Structural organization of the photosystem I

Photosystem I
  Plant Photosystem I
Identifiers
Cipher cf1.97.1.12
Enzyme bases
IntenzIntenz view
BRENDABRENDA entry
ExpasyNiceZyme view
Metacycmetabolic pathway
KeggKEGG entry
PRIAMprofile
PDB structuresRCSB PDB PDBe PDBj PDBsum
Search
PMCarticles
PubMedarticles
NCBINCBI proteins
PsaA_PsaB
 
The structure of Photosystem I from cyanobacteria. The integral part (core) and proteins of the external antenna are shown.
Identifiers
SymbolPsaA_PsaB
PfamPF00223
InterproIPR001280
PROSITEPDOC00347
SCOP1jb0
SUPERFAMILY1jb0
Tcdb5.B.4
OPM superfamily2
OPM protein1jb0
Available protein structures
Pfamthe structure
PDBRCSB PDB ; PDBe ; PDBj
PDBsum3D model

Photosystem I consists of the following protein subunits and cofactors [5] [6] [1] :

SubunitsDescription
A83 kDa , 751 amino acid residues
B82.5 kDa, 735 amino acid residues
C8.9 kDa, electron transfer from P 700 to ferredoxin
D19 kDa, provides a link to ferredoxin
E7.5 kDa, provides a link with ferredoxin
F19 kDa, interacts with plastocyanin
G8 kDa, only in plants
H10 kDa, in plants prevents the formation of PSI trimers, provides interaction with the light-harvesting complex II
I5 kDa, in plants interacts with PsaH, binds to light-harvesting complex II; in cyanobacteria plays an important role in the formation of FSI trimers
J5 kDa, carries three chlorophyll molecules and performs a structural function
K8.5 kDa, carries two chlorophyll molecules and performs a structural function
L16 kDa, in cyanobacteria they participate in the formation of the PSI trimer; in plants, it binds to the light-harvesting complex II
M3.5 kDa, only in cyanobacteria ; located in the FSI contact area in the trimer
N9 kDa, in plants and algae
Oonly in plants ; unknown function
X4 kDa, only in cyanobacteria
Pigments
Chlorophyll a95 molecules in the antenna system
Chlorophyll a2 molecules of additional chlorophyll a
Chlorophyll a 0Chlorophyll a 695 - primary electron acceptor
Chlorophylls a and a 'special pair P 700
β-carotene22 molecules
Coenzymes / Cofactors
F aFe 4 S 4 iron-sulfur cluster (ETC)
F bFe 4 S 4 iron-sulfur cluster (ETC)
F xFe 4 S 4 iron-sulfur cluster (ETC)
FerredoxinElectron carrier
PlastocyaninSoluble protein containing copper atom
Q K -APhylloquinone - electron acceptor in the ETZ (subunit A)
Q K -BPhylloquinone - electron acceptor in the ETZ (subunit B)
Ca 2+calcium ion
Mg 2+magnesium ion

The main function of PSI is the transfer of light energy to an electron, electron transfer from plastocyanin to ferredoxin [7] . PSI contains over 110 cofactors , significantly more than photosystem II [8] . Each of these components has a wide range of functions. The main components of the FSI electron transport chain are the main donor of excited P 700 electrons (chlorophyll dimer ) and five carriers: A 0 ( chlorophyll a ), A 1 ( phylloquinone ) and three Fe 4 S 4 iron-sulfur clusters: F x , F a , and F b [9] .

Structurally, PSI is a heterodimer of two integral protein complexes - A and B (in all plants, the chloroplast genes PsaA and PsaB are encoded ). Proteins A and B add the P700 dimer, one molecule of chlorophyll a monomer (Chl 695 ) - the primary electron acceptor A 0 , one additional chlorophyll a and one phylloquinone molecule (A 1 ). Two sets of additional chlorophylls a, primary electron acceptors and phylloquinones form two almost symmetrical branches of electron transport from P700 to F x . Unlike the reaction centers of green and purple bacteria and PSII, where only one of the two branches functions, both branches of electron transport are active in PSI, although they are not identical [1]. Protein A is homologous to proteins D 1 + CP43 (molecular weight of protein A corresponds to the sum of the molecular weights of proteins D 1 and CP43) from photosystem II, and protein B is homologous to proteins D 2 + CP47, respectively [10] .

Both subunits contain 11 . The iron-containing F x cluster is linked by four cysteines , two of which are located on subunit A, and two more on subunit B. In both proteins, cysteines are located at the proximal end, in a loop between the ninth and tenth transmembrane segments. In all likelihood, the so-called leucine zipper motif is located below cysteines, which makes a significant contribution to the dimerization of proteins A and B [11] . The final electron acceptors F A and F B are located on subunit C [12] [13] .

It should be emphasized that electron transfer is carried out in accordance with the thermodynamic potential . The increase in redox potentials in the acceptor chain provides a rapid decrease in energy, which prevents the electron from returning to the pigment and a waste of electronic excitation energy. Due to this, the excitation energy is effectively used for charge separation [14] .

Plastocyanin

 
Plastocyanin structure [15]

Plastocyanin is a small, mobile protein with a molecular weight of about 10.5 kDa. The cysteine and methionine residues are attached to its central Cu atom, and two histidine residues stabilize it on the side. With a reversible change in the valence of Cu 2+ ↔ Cu +1, plastocyanin either absorbs one electron or gives it up. Plastocyanin is an analogue of cytochrome c , which performs a similar function in the respiratory chain of mitochondria [6] .

It receives an electron from the cytochrome b 6 f complex , oxidizing cytochrome f and transferring it directly to the reaction center P 700 of photosystem I. There is a group of amino acids carrying a negative charge on the outer side of the protein [16] . Presumably, they bind to the positively charged luminal domain of the F subunit, but the binding mechanism is not well understood and remains unclear [17] .

In some algae and cyanobacteria, with a lack of copper in the medium, plastocyanin is not formed; instead, it is synthesized and functions as cytochrome c-553 [18] .

  • Plastocyanin (PC) gives one electron to oxidized P 700 + and restores it to its original state:
P700++PC(Cu+one)→P700+PC(Cu+2){\ displaystyle {\ mathsf {P_ {700} ^ {+} + PC _ {(Cu ^ {+ 1})} \ rightarrow P_ {700} + PC _ {(Cu ^ {+ 2})}}}}  

Special pair P 700

P 700 (in the English literature P700) is a dimer of chlorophyll a and chlorophyll a 'in which the ketoester group in the V ring is in the cis position relative to the plane of the molecule, with an absorption maximum of 700 nm [19] . The presence of a cis- ketoester group makes it possible to form a dimer from two chlorophylls through the formation of hydrogen bonds . P 700 receives energy from antenna complexes and uses it to raise electrons to a higher level. Further, the electron in the course of the redox reaction goes to the chain of carriers. In the oxidized state, the redox potential of P 700 is +0.52 V , and in the photoexcited state it becomes −1.2 V , that is, a powerful reducing agent is formed, which ensures the reduction of NADP + [20] [21] .

  • In accordance with the following equation, P 700 absorbs a quantum of light and passes into a photoexcited state, as a result of which one of its electrons passes from the main sublevel S 0 to the first singlet sublevel S 1 :
hν+P700→P700Sone∗{\ displaystyle {\ mathsf {{\ mathit {h \ nu}} + P_ {700} \ rightarrow P_ {700 \, _ {S_ {1}}} ^ {*}}}}  

Chlorophyll A 0

A 0 is the first electron acceptor in photosystem I. It is here that the primary photochemical separation of charges occurs between the photoexcited P 700 * and A 0 . Its absorption maximum is 695 nm (Chl a 695 ), which is explained by its interaction with the surrounding amino acid residues [19] . Its redox potential in the reduced state is −1.1 V [1] .

  • The photo-excited P 700 * gives one electron to chlorophyll A 0 , as a result of which the separation of charges occurs, and a primary radical pair is formed:
P700Sone∗+A0→P700++A0-{\ displaystyle {\ mathsf {P_ {700 \, _ {S_ {1}}} ^ {*} + A_ {0} \ rightarrow P_ {700} ^ {+} + A_ {0} ^ {-}}} }  

Phylloquinone A 1

The next acceptor is Phylloquinone A 1 , also known as Vitamin K 1 . Like chlorophyll, it possesses a phytol tail [22] , and approximately corresponds to plastoquinone Q A of photosystem II. Absorbing an electron, it forms semiquinone , a radical that restores F x , transfers it to F b and then to F a [22] [23] .

A0-+Aone→A0+Aone⋅{\ displaystyle {\ mathsf {A_ {0} ^ {-} + A_ {1} \ rightarrow A_ {0} + A_ {1} \ cdot}}}  

Iron-sulfur clusters

The iron-sulfur clusters FSI are in the form of a cube with four iron atoms and four sulfur atoms making up its eight vertices. All three clusters are bound to PSI proteins through cysteine ​​residues [24] . F x (E o '= −0.70 V) oxidizes the reduced A 1 . Further transport is carried out by iron-sulfur clusters F a and F b , characterized by low redox potentials (-0.59 and −0.55 V, respectively). Many experiments revealed a mismatch between different theories describing the location and operation of iron-sulfur clusters [24] . However, most of the results allow us to draw some general conclusions. First, F x , F a , and F b form a triangle , and F a is closer to F x than F b [24] . Secondly, electron transport begins with F x through F a to F b , or through F a to F b . There is still debate about which of the two clusters carries out electron transfer to ferredoxin [24] .

Ferredoxin

Ferredoxin is a water-soluble protein with a molecular weight of 11 kDa and containing a Fe 2 S 2 center [25] . It is noteworthy that it is a one-electron redox system, that is, it carries only one electron obtained by it from iron-sulfur clusters. It is restored by PSI on the stromal side of the membrane and in the reduced state is a strong reducing agent (E o '= –0.6 V), due to which it can be an electron carrier for various reactions occurring in the chloroplast. So, ferredoxin supplies electrons for the reduction of nitrites ( nitrite reductase ) and the assimilation of sulfur ( sulfite reductase ) in the chloroplast. He also supplies electrons for fixing atmospheric nitrogen ( nitrogenase ) in bacteria . It restores thioredoxin , a low molecular weight sulfur-containing protein that is involved in the redox regulation of chloroplasts, activating key enzymes of the Calvin cycle. In non-cyclic electron transport, ferredoxin interacts with ferredoxin-NADP (+) reductase , which reduces NADP + to NADPH (E o '= −0.32 V) in the chloroplast stroma [25] .

Light-gathering complex

 
FSI and CCI

Light harvesting complexes consist of chlorophyll a and b molecules and carotenoids connected to proteins [20] . These pigments, excited, transfer the energy of photons to the reaction center of the photosystem according to the Förster mechanism . Unlike the PSI reaction center, light-harvesting complexes can absorb in almost the entire range of the visible spectrum [26] . Antenna complexes are subdivided into internal, or integral, antennas directly connected to the photosystem complex, and peripheral mobile light-collecting complexes (CCI). So, proteins A and B attach the pigments of the internal FSI antenna: about 95 molecules of chlorophyll a and 22 molecules of β-carotene, 5 of which are in cis conformation. Small subunits J, K, L, M, and X participate in coordinating at least ten chlorophylls of the internal antenna. The pigments of the internal antenna are arranged in the form of a cylinder surrounding all the components of the electron transport chain of photosystem I. This distinguishes PSI from PSII, where pigments of the internal antennas are located on individual proteins CP43 and CP77 [1] . The external light-collecting complex CCI (LHCI) contains 80-120 chlorophyll molecules a and b, carotenoids, and consists of four subunits: Lhca1, Lhca2, Lhca3 and Lhca4 - with molecular weights of 17-24 kDa. Relatively recently, two additional subunits, Lhca5 and Lhca6, were discovered, however, their concentration in the thylakoid membrane is extremely low, and the genes encoding them are practically not expressed [27] [28] .

Cyclic Electron Transport

 
Non-cyclic electron transport

With too much light and / or closed stomata (starvation by CO 2 ), the plastoquinone pool is re- restored and, as a result, the NADP + pool is re-restored. With a lack of CO 2, NADPH cannot be consumed in the Calvin cycle , which means that the substrate for not enough. Ultimately, this leads to the fact that PSI has nowhere to dump excited electrons, and this in turn can lead to damage to the photosynthetic apparatus, oxidation of membranes and the formation of reactive oxygen species [6] . Under these conditions, in order to prevent oxidative stress and protect against photodamage, plants switch to cyclic electron transport. It is believed that reduced ferredoxin is a catalyst for cyclic transport [29] [30] .

Cyclic Photophosphorylation

At first, the electron somehow moves from the reduced ferredoxin to the plastoquinone pool. The exact mechanism of this process is not known. It is believed that this reaction is carried out by a special enzyme, ferredoxin-plastoquinone-oxidoreductase. Then, from plastoquinone through the cytochrome b 6 f -complex and plastocyanin, the electron again enters the PSI. In this case, the proton is injected into the thylakoid cavity and ATP is synthesized. Recently, ferredoxin-NADP + reductase, which can form a complex with the cytochrome b 6 f complex, has been recently considered as the most likely candidate for the role of ferredoxin-plastoquinone-oxidoreductase. Presumably, it can transfer electrons from ferredoxins directly to ubiquinone bound by the cytochrome b 6 f complex via a special heme c n [31] [32] . A large amount of data also speaks in favor of the formation of a supercomplex from a cytochrome b 6 f complex, PSI, ferredoxin-NADP + reductase, and the transmembrane protein PGRL1. The formation and decay of such a complex is believed to switch the electron flow regime from noncyclic to cyclic and vice versa [33] [34] .

Another enzyme that is possibly involved in this process is the NADH dehydrogenase complex of chloroplasts , similar to the NADH dehydrogenase complex of mitochondria and homologous to bacterial complex I [35] [36] . It oxidizes ferredoxin and dumps electrons on plastoquinone, preventing oxidative stress. The NADH dehydrogenase complex of chloroplasts forms a supercomplex with two PSIs using the proteins Lhca5 and Lhca6 [28] . The proton gradient created as a result of cyclic photophosphorylation on the thylakoid membrane is used by carrier proteins for incorporation of proteins from the stroma into the membrane [37] [38] .

Pseudocyclic transport

With a very active reduction of the pool of ferredoxins, their electrons are dumped onto O 2 with the formation of H 2 O (the so-called Mehler reaction ). It is similar to cyclic transport in that NADPH is not synthesized, but only ATP . However, under the conditions of the Mehler reaction, the ATP / ADP ratio is very large, so the amount of ADP present is not enough for ATP synthesis, and, as a result, a very high proton gradient is created on the thylakoid membrane. As a result of the reaction, the formation of the superoxide anion radical O 2 - · occurs, which is converted to O 2 and H 2 O 2 under the influence of the superoxide dismutase enzyme, and the peroxide is converted into water by the ascorbate peroxidase enzyme [6] .

Fdred+O2→Fdox+O2-⋅{\ displaystyle {\ mathsf {Fd_ {red} + O_ {2} \ rightarrow Fd_ {ox} + O_ {2} ^ {-} \ cdot}}}  

Another enzyme involved in pseudocyclic transport is terminal chloroplast oxidase , homologous to alternative plant mitochondria oxidase . It oxidizes a pool of plastoquinones with oxygen, forming water and dissipating energy in the form of heat [39] .

Thylakoid membrane localization

 
Placing photosynthetic complexes in the thylakoid membrane

Photosystem I is located in stromal thylakoids (32%), as well as in marginal (36%) and end (32%) areas of gran. This arrangement is due to the density of its surface charge and electrostatic repulsion forces with other complexes [40] .

In cyanobacteria and prochlorophytes, photosystem I is able to form trimers . This contributes to an increase in the absorption spectrum at great depths, as well as a more efficient redistribution of the excitation energy and protection from photo damage [41] . It should be noted that in eukaryotes, photosystem I lost this ability due to the presence of the H subunit, as well as a mutation in the L. subunit. Instead of eukaryotic trimerization, it interacts with the L and G subunits with large membrane light harvesting complexes that are not present in prokaryotes [42] .

Ycf4 Protein

The transmembrane protein Ycf4, found in the thylakoid membrane, is vital for the functioning of photosystem I. It participates in the assembly of the complex components; without it, photosynthesis becomes ineffective [43] .

Green Serobacteria and FSI Evolution

Molecular biological data support the fact that PSI probably evolved from the photosystem of green sulfur bacteria . The reaction centers of green sulfur bacteria, cyanobacteria, algae, and higher plants differ, however, domains that perform similar functions have a similar structure [44] . Thus, in all three systems, the redox potential is sufficient for the reduction of ferredoxin [44] . All three electron transport chains contain iron – sulfur proteins [44] . Finally, all three photosystems are a dimer of two hydrophobic proteins on which redox centers and pigments of an integrated antenna are fixed [44] . In turn, the photosystem of green sulfur bacteria contains the same cofactors as the electron transport chain of photosystem I [44] .

Gallery

  •  

    The position of chlorophylls and cofactors in photosystem I.

  •  

    Photosystem I Trimer

  •  

    ETC photosystem I

  •  

    Photosystem I and the reaction center of the bacterium.

  •  

    Model photosystem I.

See also

  • Cytochrome b6f complex
  • Terminal oxidase
  • Photosystem II
  • Photosynthesis

Notes

  1. ↑ 1 2 3 4 5 Ermakov, 2005 , p. 173-175.
  2. ↑ 1 2 3 4 5 6 Fromme P., Mathis P. Unraveling the photosystem I reaction center: a history, or the sum of many efforts (Eng.) // Photosyn. Res. : journal. - 2004. - Vol. 80 , no. 1-3 . - P. 109-124 . - DOI : 10.1023 / B: PRES.0000030657.88242.e1 . - PMID 16328814 . Archived December 22, 2015.
  3. ↑ 1 2 Ermakov, 2005 , p. 121.
  4. ↑ Ravi Danielsson, Marjaana Suorsa, Virpi Paakkarinen, Per-Åke Albertsson, Stenbjörn Styring, Eva-Mari Aro and Fikret Mamedov. Dimeric and Monomeric Organization of Photosystem II (Eng.) // The Journal of Biological Chemistry : journal. - 2006 .-- May ( no. 281 ). - P. 14241-14249 . - DOI : 10.1074 / jbc.M600634200 .
  5. ↑ Saenger W., Jordan P., Krauss N. The assembly of protein subunits and cofactors in photosystem I (English) // Curr. Opin. Struct. Biol. : journal. - 2002 .-- April ( vol. 12 , no. 2 ). - P. 244-254 . - DOI : 10.1016 / S0959-440X (02) 00317-2 . - PMID 11959504 .
  6. ↑ 1 2 3 4 Strasbourg, 2008 , p. 117.
  7. ↑ Golbeck JH Structure, function and organization of the Photosystem I reaction center complex (Eng.) // Biochim. Biophys. Acta : journal. - 1987. - Vol. 895 , no. 3 . - P. 167-204 . - DOI : 10.1016 / s0304-4173 (87) 80002-2 . - PMID 3333014 .
  8. ↑ HongQi Yu ', Ingo Gortjohann, Yana Bukman, Craig Yolley', Devendra K. Chauhan, Alexander Melkozerov and Petra Fromme. Structure and funcnions of photosystems I and II (neopr.) .
  9. ↑ Jagannathan, Bharat; Golbeck, John. Photosynthesis: Microbial (Neopr.) // Encyclopedia of Microbiology, 3rd Ed. - 2009 .-- S. 325—341 . - DOI : 10.1016 / B978-012373944-5.00352-7 .
  10. ↑ Heldt, 2011 , p. 99.
  11. ↑ Webber AN, Malkin R. Photosystem I reaction-center proteins contain leucine zipper motifs. A proposed role in dimer formation (Eng.) // FEBS Lett. : journal. - 1990 .-- May ( vol. 264 , no. 1 ). - P. 1-4 . - DOI : 10.1016 / 0014-5793 (90) 80749-9 . - PMID 2186925 .
  12. ↑ Jagannathan, Bharat; Golbeck, John. Breaking biological symmetry in membrane proteins: The asymmetrical orientation of PsaC on the pseudo-C2 symmetric Photosystem I core (English) // Cell. Mol. Life Sci. : journal. - 2009. - Vol. 66 , no. 7 . - P. 1257-1270 . - DOI : 10.1007 / s00018-009-8673-x .
  13. ↑ Jagannathan, Bharat; Golbeck, John. Understanding of the Binding Interface between PsaC and the PsaA / PsaB Heterodimer in Photosystem I // Biochemistry: journal. - 2009. - Vol. 48 . - P. 5405-5416 . - DOI : 10.1021 / bi900243f .
  14. ↑ Ermakov, 2005 , p. 157.
  15. ↑ PDB 3BQV (neopr.) .
  16. ↑ Frazão C., Sieker L., Sheldrick G., Lamzin V., LeGall J., Carrondo MA Ab initio structure solution of a dimeric cytochrome c3 from Desulfovibrio gigas containing disulfide bridges (Eng.) // J. Biol. Inorg. Chem. : journal. - 1999 .-- April ( vol. 4 , no. 2 ). - P. 162-165 . - DOI : 10.1007 / s007750050299 . - PMID 10499086 . Archived October 15, 2000.
  17. ↑ Hope AB Electron transfers amongst cytochrome f, plastocyanin and photosystem I: kinetics and mechanisms (Eng.) // Biochim. Biophys. Acta : journal. - 2000 .-- January ( vol. 1456 , no. 1 ). - P. 5-26 . - DOI : 10.1016 / S0005-2728 (99) 00101-2 . - PMID 10611452 .
  18. ↑ Zhang L1, McSpadden B., Pakrasi HB, Whitmarsh J. Copper-mediated regulation of cytochrome c553 and plastocyanin in the cyanobacterium Synechocystis 6803 (Eng.) // The journal of biological chemistry : journal. - 1992 .-- September ( vol. 267 , no. 27 ). - P. 19054-19059 . - PMID 1326543 .
  19. ↑ 1 2 Rutherford AW, Heathcote P. Primary Photochemistry in Photosystem-I (neopr.) // Photosyn. Res .. - 1985. - T. 6 , No. 4 . - S. 295-316 . - DOI : 10.1007 / BF00054105 .
  20. ↑ 1 2 Zeiger, Eduardo; Taiz, Lincoln. Ch. 7: Topic 7.8: Photosystem I // Plant physiology. - 4th. - Sunderland, Mass: Sinauer Associates, 2006. - ISBN 0-87893-856-7 .
  21. ↑ Shubin VV, Karapetyan NV, Krasnovsky AA Molecular Arrangement of Pigment-Protein Complex of Photosystem I (Eng.) // Photosyn. Res. : journal. - 1986. - Vol. 9 , no. 1-2 . - P. 3-12 . - DOI : 10.1007 / BF00029726 .
  22. ↑ 1 2 Itoh, Shigeru, Msayo Iwaki. Vitamin K 1 (Phylloquinone) Restores the Turnover of FeS centers of Ether-extracted Spinach PS I Particles. (English) // FEBS Lett. : journal. - 1989. - Vol. 243 , no. 1 . - P. 47-52 . - DOI : 10.1016 / 0014-5793 (89) 81215-3 .
  23. ↑ Palace GP, Franke JE, Warden JT Is phylloquinone an obligate electron carrier in photosystem I? (English) // FEBS Lett. : journal. - 1987 .-- May ( vol. 215 , no. 1 ). - P. 58-62 . - DOI : 10.1016 / 0014-5793 (87) 80113-8 . - PMID 3552735 .
  24. ↑ 1 2 3 4 Vassiliev IR, Antonkine ML, Golbeck JH Iron-sulfur clusters in type I reaction centers (English) // Biochim. Biophys. Acta : journal. - 2001. - October ( vol. 1507 , no. 1-3 ). - P. 139-160 . - DOI : 10.1016 / S0005-2728 (01) 00197-9 . - PMID 11687212 .
  25. ↑ 1 2 Forti, Georgio, Paola Maria Giovanna Grubas. Two Sites of Interaction of Ferredoxin with thylakoids (Eng.) // FEBS Lett. : journal. - 1985. - Vol. 186 , no. 2 . - P. 149-152 . - DOI : 10.1016 / 0014-5793 (85) 80698-0 .
  26. ↑ “The Photosynthetic Process” Archived copy (neopr.) . Date of treatment May 5, 2009. Archived February 19, 2009.
  27. ↑ Robert Lucinski, Volkmar HR Schmid, Stefan Jansson, Frank Klimmek. Lhca5 interaction with plant photosystem I (English) // FEBS letters : journal. - 2006. - Vol. 580 , no. 27 . - P. 6485-6488 . - DOI : 10.1016 / j.febslet.2006.10.063 .
  28. ↑ 1 2 Lianwei Peng, Hiroshi Yamamoto, Toshiharu Shikanai. Structure and biogenesis of the chloroplast NAD (P) H dehydrogenase complex. (English) // Biochimica et Biophysica Acta (BBA): journal. - 2011. - Vol. 1807 , no. 8 . - P. 945-953 . - DOI : 10.1016 / j.bbabio.2010.10.01.015 .
  29. ↑ Krendeleva T. E., Kukarskih G. P., Timofeev K. N., Ivanov B. N., Rubin A. B. Ferredoxin-dependent cyclic electron transport in isolated thylakoids occurs with the participation of ferredoxin-NADP reductase. Doklady of the Academy of Sciences, 2001.379 (5): p. 1-4.
  30. ↑ Kovalenko I.B., Ustinin D.M., Grachev N.E., Krendeleva T.E., Kukarskih G.P., Timofeev K.N., Riznichenko G.Yu., Grachev E.A., Rubin A.B. Experimental and theoretical study of cyclic electron transport processes around photosystem 1 (rus.) // Biophysics: Journal. - 2003. - T. 48 , No. 4 . - S. 656-665 .
  31. ↑ Cramer WA .; Zhang H .; Yan j .; Kurisu G .; Smith JL. Transmembrane traffic in the cytochrome b6f complex. (Eng.) // Annu Rev Biochem : journal. - 2006. - Vol. 75 . - P. 769-790 . - DOI : 10.1146 / annurev.biochem.75.103004.142756 . - PMID 16756511 .
  32. ↑ Cramer WA .; Yan J .; Zhang H .; Kurisu G .; Smith JL. Structure of the cytochrome b6f complex: new prosthetic groups, Q-space, and the 'hors d'oeuvres hypothesis' for assembly of the complex. (English) // Photosynth Res: journal. - 2005. - Vol. 85 , no. 1 . - P. 133-143 . - DOI : 10.1007 / s11120-004-2149-5 . - PMID 15977064 .
  33. ↑ Masakazu Iwai, Kenji Takizawa, Ryutaro Tokutsu, Akira Okamuro, Yuichiro Takahashi & Jun Minagawa. Isolation of the elusive supercomplex that drives cyclic electron flow in photosynthesis (Eng.) // Nature: journal. - 2010 .-- 22 April ( vol. 464 ). - P. 1210-1213 . - DOI : 10.1038 / nature08885 .
  34. ↑ Hiroko Takahashi, Sophie Clowez, Francis-André Wollman, Olivier Vallon & Fabrice Rappaport. Cyclic electron flow is redox-controlled but independent of state transition (English) // Nature Communications : journal. - Nature Publishing Group , 2013 .-- 13 June ( vol. 4 ). - DOI : 10.1038 / ncomms2954 .
  35. ↑ Lianwei Peng, Hideyuki Shimizu, Toshiharu Shikanai ,. The Chloroplast NAD (P) H Dehydrogenase Complex Interacts with Photosystem I in Arabidopsis. (Eng.) // J Biol Chem. : journal. - 2008 .-- Vol. 283 , no. 50 . - P. 34873—34879. . - DOI : 10.1074 / jbc.M803207200 .
  36. ↑ Yamori W., Sakata N., Suzuki Y., Shikanai T., Makino A. Cyclic electron flow around photosystem I via chloroplast NAD(P)H dehydrogenase (NDH) complex performs a significant physiological role during photosynthesis and plant growth at low temperature in rice. (англ.) // Plant J. : journal. - 2011. - Vol. 68 , no. 6 . — P. 966—976 . — DOI : 10.1111/j.1365-313X.2011.04747.x .
  37. ↑ Chaddock, AM; Mant, A.; Karnauchov, I.; Brink, S.; Herrmann, RG; Klösgen, RB; Robinson, C. A new type of signal peptide: central role of a twin-arginine motif in transfer signals for the delta pH-dependent thylakoidal protein translocase. (англ.) // EMBO J. : journal. - 1995. - Vol. 14 , no. 12 . — P. 2715—2722 . — PMID 7796800 .
  38. ↑ Kenneth Cline and Hiroki Mori. Thylakoid ΔpH-dependent precursor proteins bind to a cpTatC–Hcf106 complex before Tha4-dependent transport. (англ.) // J Cell Biol. : journal. — 2001. — 20 August ( vol. 154 , no. 4 ). — P. 719—730 . — DOI : 10.1083/jcb.200105149 .
  39. ↑ McDonald AE, Ivanov AG, Bode R., Maxwell DP, Rodermel SR, Hüner NP Flexibility in photosynthetic electron transport: the physiological role of plastoquinol terminal oxidase (PTOX) (англ.) // Biochim. Biophys. Acta : journal. — 2011. — August ( vol. 1807 , no. 8 ). — P. 954—967 . — DOI : 10.1016/j.bbabio.2010.10.024 . — PMID 21056542 .
  40. ↑ Ермаков, 2005 , с. 123.
  41. ↑ Navassard V. Karapetyan, Alfred R. Holzwarth, Matthias Rögner. The photosystem I trimer of cyanobacteria: molecular organization, excitation dynamics and physiological significance (англ.) // FEBS letters : journal. - 1999. - Vol. 460 , no. 3 . — P. 395—400 . — DOI : 10.1016/S0014-5793(99)01352-6 .
  42. ↑ Adam Ben-Shema, Felix Frolowb, Nathan Nelsona,. Evolution of photosystem I – from symmetry through pseudosymmetry to asymmetry (англ.) // FEBS letters : journal. — 30 April 2004. — Vol. 565 , no. 3 . — P. 274—280 . — DOI : 10.1016/S0014-5793(04)00360-6 .
  43. ↑ Boudreau E., Takahashi Y., Lemieux C., Turmel M., Rochaix JD The chloroplast ycf3 and ycf4 open reading frames of Chlamydomonas reinhardtii are required for the accumulation of the photosystem I complex. (англ.) // EMBO J : journal. - 1997. - Vol. 16 , no. 20 . — P. 6095—6104 . — DOI : 10.1093/emboj/16.20.6095 . — PMID 9321389 .
  44. ↑ 1 2 3 4 5 Lockau, Wolfgang, Wolfgang Nitschke. Photosystem I and its Bacterial Counterparts (англ.) // Physiologia Plantarum : journal. - 1993. - Vol. 88 , no. 2 . — P. 372—381 . — DOI : 10.1111/j.1399-3054.1993.tb05512.x .

Literature

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Links

  • Информационная система «Фотосинтетическая мембрана»
  • «Циклический и нециклический поток электронов.» в онлайн энциклопедии Физиология растений
Источник — https://ru.wikipedia.org/w/index.php?title=Фотосистема_I&oldid=100966674


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