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IPR008797 is a Oxygen-evolving enhancer protein 3.
<p>In PSII, the oxygen-evolving complex (OEC) is responsible for catalysing the splitting of water to O(2) and 4H+. The OEC is composed of a cluster of manganese, calcium and chloride ions bound to extrinsic proteins. In cyanobacteria there are five extrinsic proteins in OEC (PsbO, PsbP-like, PsbQ-like, PsbU and PsbV), while in plants there are only three (PsbO, PsbP and PsbQ), PsbU and PsbV having been lost during the evolution of green plants [[cite:PUB00015369]].</p> <p>This family represents the PSII OEC protein PsbQ from cyanobacteria and plants. Both PsbQ and PsbP ([interpro:IPR002683]) are regulators that are necessary for the biogenesis of optically active PSII. The crystal structure of PsbQ from spinach revealed a 4-helical bundle polypeptide. The distribution of positive and negative charges on the protein surface might explain the ability of PsbQ to increase the binding of chloride and calcium ions and make them available to PSII [[cite:PUB00015372]].</p> <p>Oxygenic photosynthesis uses two multi-subunit photosystems (I and II) located in the cell membranes of cyanobacteria and in the thylakoid membranes of chloroplasts in plants and algae. Photosystem II (PSII) has a P680 reaction centre containing chlorophyll 'a' that uses light energy to carry out the oxidation (splitting) of water molecules, and to produce ATP via a proton pump. Photosystem I (PSI) has a P700 reaction centre containing chlorophyll that takes the electron and associated hydrogen donated from PSII to reduce NADP+ to NADPH. Both ATP and NADPH are subsequently used in the light-independent reactions to convert carbon dioxide to glucose using the hydrogen atom extracted from water by PSII, releasing oxygen as a by-product [[cite:PUB00152828]].</p> <p>PSII is a multisubunit protein-pigment complex containing polypeptides both intrinsic and extrinsic to the photosynthetic membrane [[cite:PUB00152828], [cite:PUB00015357], [cite:PUB00015358], [cite:PUB00097583]]. Within the core of the complex, the chlorophyll and β-carotene pigments are mainly bound to the antenna proteins CP43 (PsbC) and CP47 (PsbB), which pass the excitation energy on to the reaction centre proteins D1 (Qb, PsbA) and D2 (Qa, PsbD) that bind all the redox-active cofactors involved in the energy conversion process. The PSII oxygen-evolving complex (OEC) oxidises water to provide protons for use by PSI, and consists of OEE1 (PsbO), OEE2 (PsbP) and OEE3 (PsbQ). The remaining subunits in PSII are of low molecular weight (less than 10kDa), and are involved in PSII assembly, stabilisation, dimerisation, and photo-protection [[cite:PUB00015359]].</p>
This description is obtained from EB-eye REST.
GO predictions are based solely on the InterPro-to-GO mappings published by EMBL-EBI, which are in turn based on the mapping of predicted domains to the InterPro dataset. The InterPro-to-GO mapping was last updated on , while the GO metadata was last updated on .
| GO term | Namespace | Name | Definition | Relationships |
|---|---|---|---|---|
| Molecular function | Calcium ion binding | Interacting selectively and non-covalently with calcium ions (Ca2+). | ||
| Cellular component | Photosystem II | A photosystem that contains a pheophytin-quinone reaction center with associated accessory pigments and electron carriers. In cyanobacteria and chloroplasts, in the presence of light, PSII functions as a water-plastoquinone oxidoreductase, transferring electrons from water to plastoquinone, whereas other photosynthetic bacteria carry out anoxygenic photosynthesis and oxidize other compounds to re-reduce the photoreaction center. | ||
| Cellular component | Photosystem II oxygen evolving complex | A complex, composed of a cluster of manganese, calcium and chloride ions bound to extrinsic proteins, that catalyzes the splitting of water to O2 and 4 H+. In cyanobacteria there are five extrinsic proteins in OEC (PsbO, PsbP-like, PsbQ-like, PsbU and PsbV), while in plants there are only three (PsbO, PsbP and PsbQ). | ||
| Biological process | Photosynthesis | The synthesis by organisms of organic chemical compounds, especially carbohydrates, from carbon dioxide (CO2) using energy obtained from light rather than from the oxidation of chemical compounds. | ||
| Cellular component | Extrinsic component of membrane | The component of a membrane consisting of gene products and protein complexes that are loosely bound to one of its surfaces, but not integrated into the hydrophobic region. |
| Transcript | Name | Description | Predicted domains | Domain count |
|---|---|---|---|---|
| – | PREDICTED: oxygen-evolving enhancer protein 3-1, chloroplastic-like [Glycine max] gi|356569902|ref|XP_003553133.1| | 7 | ||
| – | PREDICTED: psbQ-like protein 3, chloroplastic-like isoform X1 [Cicer arietinum] gi|502129935|ref|XP_004500474.1| | 7 | ||
| – | PREDICTED: psbQ-like protein 3, chloroplastic-like isoform X1 [Cicer arietinum] gi|502129935|ref|XP_004500474.1| | 7 | ||
| – | PREDICTED: LOW QUALITY PROTEIN: psbQ-like protein 1, chloroplastic-like [Cicer arietinum] gi|502093977|ref|XP_004490109.1| | 9 | ||
| – | PREDICTED: oxygen-evolving enhancer protein 3, chloroplastic-like [Cicer arietinum] gi|502173623|ref|XP_004515373.1| | 8 | ||
| – | PREDICTED: oxygen-evolving enhancer protein 3-1, chloroplastic-like [Glycine max] gi|356543952|ref|XP_003540422.1| | 8 | ||
| – | Photosynthetic NDH subcomplex L 2; TAIR: AT1G14150.1 PsbQ-like 2; Swiss-Prot: sp|Q9XI73|PNSL2_ARATH Photosynthetic NDH subunit of lumenal location 2, chloroplastic; TrEMBL-Plants: tr|I3SD98|I3SD98_LOTJA Uncharacterized protein; Found in the gene: LotjaGi2g1v0301400 | 9 | ||
| – | Photosynthetic NDH subcomplex L 3; TAIR: AT3G01440.1 PsbQ-like 1; Swiss-Prot: sp|Q9SGH4|PNSL3_ARATH Photosynthetic NDH subunit of lumenal location 3, chloroplastic; TrEMBL-Plants: tr|I3SQW5|I3SQW5_LOTJA Uncharacterized protein; Found in the gene: LotjaGi3g1v0234900 | 8 | ||
| – | Photosynthetic NDH subcomplex L 3; TAIR: AT3G01440.1 PsbQ-like 1; Swiss-Prot: sp|Q9SGH4|PNSL3_ARATH Photosynthetic NDH subunit of lumenal location 3, chloroplastic; TrEMBL-Plants: tr|I3SQW5|I3SQW5_LOTJA Uncharacterized protein; Found in the gene: LotjaGi3g1v0234900 | 7 | ||
| – | Oxygen-evolving enhancer protein 3-2, chloroplastic; TAIR: AT2G01918.1 PsbQ-like 3; Swiss-Prot: sp|Q2V4B2|PQL3_ARATH PsbQ-like protein 3, chloroplastic; TrEMBL-Plants: tr|C6TCX0|C6TCX0_SOYBN Putative uncharacterized protein; Found in the gene: LotjaGi6g1v0049100 | 7 |
A list of co-occurring predicted domains within the L. japonicus gene space:
| Predicted domain | Source | Observations | Saturation (%) |
|---|---|---|---|
| SSF101112 | SUPERFAMILY | 1 | 10.00 |