- EMDB-12697: Structure of a Minimal Photosystem I -
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基本情報
登録情報
データベース: EMDB / ID: EMD-12697
タイトル
Structure of a Minimal Photosystem I
マップデータ
試料
複合体: Minimal Photosystem I
タンパク質・ペプチド: x 7種
リガンド: x 8種
キーワード
Photosystem I / excitation energy transfer / cyanobacteria / minimal structure / PHOTOSYNTHESIS
機能・相同性
機能・相同性情報
plasma membrane-derived photosystem I / photosystem I reaction center / photosystem I / photosystem I / plasma membrane-derived thylakoid membrane / chlorophyll binding / photosynthetic electron transport in photosystem I / photosynthesis / 4 iron, 4 sulfur cluster binding / electron transfer activity ...plasma membrane-derived photosystem I / photosystem I reaction center / photosystem I / photosystem I / plasma membrane-derived thylakoid membrane / chlorophyll binding / photosynthetic electron transport in photosystem I / photosynthesis / 4 iron, 4 sulfur cluster binding / electron transfer activity / oxidoreductase activity / magnesium ion binding / metal ion binding 類似検索 - 分子機能
Photosystem I reaction center subunit PsaK / Photosystem I reaction centre subunit PsaK / Photosystem I PsaM, reaction centre superfamily / Photosystem I PsaM, reaction centre / Photosystem I protein M (PsaM) / Photosystem I reaction centre subunit PsaK superfamily / Photosystem I psaG and psaK proteins signature. / Photosystem I reaction center subunit V/PsaK / : / Photosystem I psaG / psaK ...Photosystem I reaction center subunit PsaK / Photosystem I reaction centre subunit PsaK / Photosystem I PsaM, reaction centre superfamily / Photosystem I PsaM, reaction centre / Photosystem I protein M (PsaM) / Photosystem I reaction centre subunit PsaK superfamily / Photosystem I psaG and psaK proteins signature. / Photosystem I reaction center subunit V/PsaK / : / Photosystem I psaG / psaK / Photosystem I PsaD / Photosystem I, reaction centre subunit PsaD superfamily / PsaD / Photosystem I PsaE, reaction centre subunit IV / Photosystem I reaction centre subunit IV / PsaE / Photosystem I protein PsaC / Photosystem I PsaA / Photosystem I PsaB / Photosystem I PsaA/PsaB, conserved site / Photosystem I psaA and psaB proteins signature. / Photosystem I PsaA/PsaB / Photosystem I PsaA/PsaB superfamily / Photosystem I psaA/psaB protein / Electron transport accessory-like domain superfamily / 4Fe-4S dicluster domain / 4Fe-4S ferredoxin, iron-sulphur binding, conserved site / 4Fe-4S ferredoxin-type iron-sulfur binding region signature. / 4Fe-4S ferredoxin-type iron-sulfur binding domain profile. / 4Fe-4S ferredoxin-type, iron-sulphur binding domain 類似検索 - ドメイン・相同性
Photosystem I reaction center subunit IV / Photosystem I reaction center subunit II / Photosystem I P700 chlorophyll a apoprotein A1 / Photosystem I P700 chlorophyll a apoprotein A2 / Photosystem I iron-sulfur center / Photosystem I reaction center subunit XII / Photosystem I reaction center subunit PsaK 2 類似検索 - 構成要素
ジャーナル: J Am Chem Soc / 年: 2021 タイトル: Two-Dimensional Electronic Spectroscopy of a Minimal Photosystem I Complex Reveals the Rate of Primary Charge Separation. 著者: Parveen Akhtar / Ido Caspy / Paweł J Nowakowski / Tirupathi Malavath / Nathan Nelson / Howe-Siang Tan / Petar H Lambrev / 要旨: Photosystem I (PSI), found in all oxygenic photosynthetic organisms, uses solar energy to drive electron transport with nearly 100% quantum efficiency, thanks to fast energy transfer among antenna ...Photosystem I (PSI), found in all oxygenic photosynthetic organisms, uses solar energy to drive electron transport with nearly 100% quantum efficiency, thanks to fast energy transfer among antenna chlorophylls and charge separation in the reaction center. There is no complete consensus regarding the kinetics of the elementary steps involved in the overall trapping, especially the rate of primary charge separation. In this work, we employed two-dimensional coherent electronic spectroscopy to follow the dynamics of energy and electron transfer in a monomeric PSI complex from PCC 6803, containing only subunits A-E, K, and M, at 77 K. We also determined the structure of the complex to 4.3 Å resolution by cryoelectron microscopy with refinements to 2.5 Å. We applied structure-based modeling using a combined Redfield-Förster theory to compute the excitation dynamics. The absorptive 2D electronic spectra revealed fast excitonic/vibronic relaxation on time scales of 50-100 fs from the high-energy side of the absorption spectrum. Antenna excitations were funneled within 1 ps to a small pool of chlorophylls absorbing around 687 nm, thereafter decaying with 4-20 ps lifetimes, independently of excitation wavelength. Redfield-Förster energy transfer computations showed that the kinetics is limited by transfer from these red-shifted pigments. The rate of primary charge separation, upon direct excitation of the reaction center, was determined to be 1.2-1.5 ps. This result implies activationless electron transfer in PSI.