Summary: Photosystem I reaction centre subunit VIII
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This is the Wikipedia entry entitled "Sea anemone neurotoxin". More...
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Sea anemone neurotoxin Edit Wikipedia article
Structure of the neurotoxin ATX Ia from Anemonia sulcata.
|Antihypertensive protein BDS-I/II|
Structure of the antihypertensive and antiviral protein BDS-I from the sea anemone Anemonia sulcata.
Sea anemone neurotoxin is the name given to neurotoxins produced by sea anemones with related structure and function. Sea anemone neurotoxins can be divided in two functional groups that either specifically target the sodium channel or the potassium channel.
A number of proteins belong to the sodium channel toxin family, including calitoxin and anthopleurin. The neurotoxins bind specifically to the sodium channel, thereby delaying its inactivation during signal transduction, resulting in strong stimulation of mammalian cardiac muscle contraction. Calitoxin 1 has been found in neuromuscular preparations of crustaceans, where it increases transmitter release, causing firing of the axons. Three disulfide bonds are present in this protein.
This family also includes the antihypertensive and antiviral proteins BDS-I ( ) and BDS-II ( ) expressed by Anemonia viridis (previously Anemonia sulcata). BDS-I is organised into a triple-stranded antiparallel beta-sheet, with an additional small antiparallel beta-sheet at the N-terminus. Both peptides are known to specifically block the Kv3.4 potassium channel, and thus bring about a decrease in blood pressure. Moreover, they inhibit the cytopathic effects of mouse hepatitis virus strain MHV-A59 on mouse liver cells, by an unknown mechanism.
- Widmer H, Billeter M, Wüthrich K (1989). "Three-dimensional structure of the neurotoxin ATX Ia from Anemonia sulcata in aqueous solution determined by nuclear magnetic resonance spectroscopy". Proteins. 6 (4): 357–71. doi:10.1002/prot.340060403. PMID 2576133.
- Driscoll PC, Gronenborn AM, Beress L, Clore GM (March 1989). "Determination of the three-dimensional solution structure of the antihypertensive and antiviral protein BDS-I from the sea anemone Anemonia sulcata: a study using nuclear magnetic resonance and hybrid distance geometry-dynamical simulated annealing". Biochemistry. 28 (5): 2188–98. doi:10.1021/bi00431a033. PMID 2566326.
- Norton TR (1981). "Cardiotonic polypeptides from Anthopleura xanthogrammica (Brandt) and A. elegantissima (Brandt)". Fed. Proc. 40 (1): 21–5. PMID 6108877.
- Yasunobu KT, Norton TR, Reimer NS, Yasunobu CL (1985). "Amino acid sequence of the Anthopleura xanthogrammica heart stimulant, anthopleurin-B". J. Biol. Chem. 260 (15): 8690–3. PMID 4019448.
- Scanlon MJ, Pallaghy PK, Norton RS, Monks SA (1995). "Solution structure of the cardiostimulant polypeptide anthopleurin-B and comparison with anthopleurin-A". Structure. 3 (8): 791–803. doi:10.1016/s0969-2126(01)00214-3. PMID 7582896.
- Clore GM, Driscoll PC, Gronenborn AM, Beress L (1989). "Determination of the three-dimensional solution structure of the antihypertensive and antiviral protein BDS-I from the sea anemone Anemonia sulcata: a study using nuclear magnetic resonance and hybrid distance geometry-dynamical simulated annealing". Biochemistry. 28 (5): 2188–2198. doi:10.1021/bi00431a033. PMID 2566326.
- Lazdunski M, Schweitz H, Diochot S, Beress L (1998). "Sea anemone peptides with a specific blocking activity against the fast inactivating potassium channel Kv3.4". J. Biol. Chem. 273 (12): 6744–6749. doi:10.1074/jbc.273.12.6744. PMID 9506974.
- Schweitz, Hugues; Bruhn, Thomas; Guillemare, Eric; Moinier, Danielle; Lancelin, Jean-Marc; Béress, László; Lazdunski, Michel (1995-10-20). "Kalicludines and Kaliseptine TWO DIFFERENT CLASSES OF SEA ANEMONE TOXINS FOR VOLTAGE-SENSITIVE K+ CHANNELS". Journal of Biological Chemistry. 270 (42): 25121–25126. doi:10.1074/jbc.270.42.25121. ISSN 0021-9258. PMID 7559645.
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Photosystem I reaction centre subunit VIII Provide feedback
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External database links
This tab holds annotation information from the InterPro database.
InterPro entry IPR001302
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.
This entry represents subunit VIII (PsaI) of the photosystem I (PSI) reaction centre. PSI is located, along with photosystem II (PSII), in the thylakoid photosynthetic membranes of plants, green algae and cyanobacteria. The crystal structure of PSI from the thermophilic cyanobacterium Synechococcus elongatus (Thermosynechococcus elongatus) has 12 protein subunits and 127 cofactors comprising 96 chlorophylls, 2 phylloquinones, 3 4Fe4S clusters, 22 carotenoids, 4 lipids, and a putative calcium ion [PUBMED:11418848]. PsaI consists of a single transmembrane helix, and has a crucial role in aiding normal structural organisation of PsaL within the PSI complex and the absence of PsaI alters PsaL organisation, leading to a small, but physiologically significant, defect in PSI function [PUBMED:7608190]. PsaL encodes a subunit of PSI and is necessary for trimerisation of PSI. PsaL may constitute the trimer-forming domain in the structure of PSI [PUBMED:8262256].
The mapping between Pfam and Gene Ontology is provided by InterPro. If you use this data please cite InterPro.
|Cellular component||photosystem I (GO:0009522)|
|Biological process||photosynthesis (GO:0015979)|
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1Cannot generate PP/Heatmap alignments for seeds; no PP data available
Key: available, not generated, — not available.
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|Seed source:||Pfam-B_528 (release 2.1)|
|Number in seed:||26|
|Number in full:||115|
|Average length of the domain:||25.00 aa|
|Average identity of full alignment:||56 %|
|Average coverage of the sequence by the domain:||60.29 %|
|HMM build commands:||
build method: hmmbuild -o /dev/null HMM SEED
search method: hmmsearch -Z 26740544 -E 1000 --cpu 4 HMM pfamseq
|Family (HMM) version:||17|
|Download:||download the raw HMM for this family|
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There are 4 interactions for this family. More...
We determine these interactions using iPfam, which considers the interactions between residues in three-dimensional protein structures and maps those interactions back to Pfam families. You can find more information about the iPfam algorithm in the journal article that accompanies the website.
For those sequences which have a structure in the Protein DataBank, we use the mapping between UniProt, PDB and Pfam coordinate systems from the PDBe group, to allow us to map Pfam domains onto UniProt sequences and three-dimensional protein structures. The table below shows the structures on which the PSI_8 domain has been found. There are 15 instances of this domain found in the PDB. Note that there may be multiple copies of the domain in a single PDB structure, since many structures contain multiple copies of the same protein sequence.
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