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Literature summary for 1.97.1.12 extracted from

  • Milanovsky, G.; Petrova, A.; Cherepanov, D.; Semenov, A.
    Kinetic modeling of electron transfer reactions in photosystem I complexes of various structures with substituted quinone acceptors (2017), Photosynth. Res., 133, 185-199 .
    View publication on PubMed

KM Value [mM]

KM Value [mM] KM Value Maximum [mM] Substrate Comment Organism Structure
additional information
-
additional information Michaelis-Menten kinetics, three-state electron transport recombinantion kinetics, and kinetic modeling, interaction of PS I with external acceptors, methylviologen, and oxygen, detailed overview Synechocystis sp. PCC 6803

Localization

Localization Comment Organism GeneOntology No. Textmining
thylakoid membrane
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Synechocystis sp. PCC 6803 42651
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Natural Substrates/ Products (Substrates)

Natural Substrates Organism Comment (Nat. Sub.) Natural Products Comment (Nat. Pro.) Rev. Reac.
reduced plastocyanin + oxidized ferredoxin + hv Synechocystis sp. PCC 6803
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oxidized plastocyanin + reduced ferredoxin
-
?

Organism

Organism UniProt Comment Textmining
Synechocystis sp. PCC 6803 P29254 AND P29255 AND P32422 psaA, psaB, and psaC
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Substrates and Products (Substrate)

Substrates Comment Substrates Organism Products Comment (Products) Rev. Reac.
additional information upon light excitation, the excited singlet state of the primary electron donor, P700 delivers an electron to the primary Chl acceptor A0A/ A0B forming the charge-separated state P700 +A0-. The electron is then transferred in sequence to A1A/ A1B, to the iron-sulfur cluster FX, and ultimately to FA/FB. The side production of superoxide radical in the A1-site by oxygen reduction via the Mehler reaction might comprise about 0.3% of the total electron flow in photosystem I, PS I. Interaction of PS I with external acceptors, methylviologen, 2,3-dichloro-naphthoquinone and oxygen, overview. Analysis of PS I complexes containing various quinones in the A1-binding site, i.e. phylloquinone PhQ, plastoquinone-9 PQ and 2,3-dichloro-naphthoquinone, as well as FX-core complexes, depleted of terminal iron-sulfur FA/FB clusters Synechocystis sp. PCC 6803 ?
-
?
reduced plastocyanin + oxidized ferredoxin + hv
-
Synechocystis sp. PCC 6803 oxidized plastocyanin + reduced ferredoxin
-
?

Subunits

Subunits Comment Organism
More the membrane-embedded core of each PS I monomer is formed by the two largest subunits, PsaA and PsaB, which bind electron transport cofactors arranged in two symmetrical branches, A and B, extending from P700, a pair of chlorophyll a molecules located on the lumenal side, to the [4Fe-4S] cluster FX, placed on the opposite stromal side of the complex Synechocystis sp. PCC 6803

Synonyms

Synonyms Comment Organism
PS I
-
Synechocystis sp. PCC 6803

Cofactor

Cofactor Comment Organism Structure
phylloquinone
-
Synechocystis sp. PCC 6803
plastoquinone
-
Synechocystis sp. PCC 6803
[4Fe-4S]-center cluster Fx Synechocystis sp. PCC 6803

General Information

General Information Comment Organism
additional information the membrane-embedded core of each PS I monomer is formed by the two largest subunits, PsaA and PsaB, which bind electron transport cofactors arranged in two symmetrical branches, A and B, extending from P700, a pair of chlorophyll a molecules located on the lumenal side, to the [4Fe-4S] cluster FX, placed on the opposite stromal side of the complex. Each of the two branches, related by a pseudo-C2 rotation axis which passes through P700 and FX, carries two electronically coupled Chl a molecules (termed A0A or A0B) and one phylloquinone A1A or A1B Synechocystis sp. PCC 6803
physiological function photosystem I (PS I) is a key pigment-protein complex of the electron transfer (ET) chain of oxygenic photosynthetic organisms. It includes both a large antenna system for harvesting solar energy and a photochemical reaction center catalyzing charge separation across the membrane. PS I is the key element of the energy-transducing pathways because the electron flow in thylakoids is controlled by the redox states of cofactors in the acceptor part of PS I Synechocystis sp. PCC 6803