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7  structures 29  species 0  interactions 33  sequences 3  architectures

Family: Toxin_9 (PF02819)

Summary: Spider toxin

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This is the Wikipedia entry entitled "Spider toxin". More...

Spider toxin Edit Wikipedia article

Spider toxin
Solution structure of omega-agatoxin-Aa4a from Agelenopsis aperta.[1]
Pfam clanCL0083
OPM superfamily112
OPM protein1agg
Delta Atracotoxin
OPM protein1vtx
Spider toxin CSTX family
Spider potassium channel inhibitory toxin
Pfam clanCL0083
OPM superfamily112
OPM protein1qk6

Spider toxins are a family of proteins produced by spiders which function as neurotoxins. The mechanism of many spider toxins is through blockage of calcium channels.

A remotely related group of atracotoxins operate by opening sodium channels. δ-Atracotoxin from the venom of the Sydney funnel-web spider produces potentially fatal neurotoxic symptoms in primates by slowing the inactivation of voltage-gated sodium channels.[2] The structure of atracotoxin comprises a core beta region containing a triple-stranded a thumb-like extension protruding from the beta region and a C-terminal helix. The beta region contains a cystine knot motif, a feature seen in other neurotoxic polypeptides[2] and other spider toxins, of the CSTX family.

Spider potassium channel inhibitory toxins is another group of spider toxins. A representative of this group is hanatoxin, a 35 amino acid peptide toxin which was isolated from Chilean rose tarantula (Grammostola rosea, syn. G. spatulata) venom. It inhibits the drk1 voltage-gated potassium channel by altering the energetics of gating.[3] See also Huwentoxin-1 InterProIPR013140.

See also


  1. ^ PDB: 1IVA​; Reily MD, Holub KE, Gray WR, Norris TM, Adams ME (December 1994). "Structure-activity relationships for P-type calcium channel-selective omega-agatoxins". Nat. Struct. Biol. 1 (12): 853–6. doi:10.1038/nsb1294-853. PMID 7773772.
  2. ^ a b Mackay JP, King GF, Fletcher JI, Chapman BE, Howden ME (1997). "The structure of versutoxin (delta-atracotoxin-Hv1) provides insights into the binding of site 3 neurotoxins to the voltage-gated sodium channel". Structure. 5 (11): 1525–1535. doi:10.1016/S0969-2126(97)00301-8. PMID 9384567.
  3. ^ Shimada I, Sato K, Takahashi H, Kim JI, Min HJ, Swartz KJ (2000). "Solution structure of hanatoxin1, a gating modifier of voltage-dependent K(+) channels: common surface features of gating modifier toxins". J. Mol. Biol. 297 (3): 771–780. doi:10.1006/jmbi.2000.3609. PMID 10731427.

Further reading

  • Kim JI, Konishi S, Iwai H, Kohno T, Gouda H, Shimada I, Sato K, Arata Y (July 1995). "Three-dimensional solution structure of the calcium channel antagonist omega-agatoxin IVA: consensus molecular folding of calcium channel blockers". J. Mol. Biol. 250 (5): 659–71. doi:10.1006/jmbi.1995.0406. PMID 7623383.
This article incorporates text from the public domain Pfam and InterPro: IPR008017

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Spider toxin Provide feedback

This family of spider neurotoxins are thought to be calcium ion channel inhibitors.

Literature references

  1. Kim JI, Konishi S, Iwai H, Kohno T, Gouda H, Shimada I, Sato K, Arata Y; , J Mol Biol 1995;250:659-671.: Three-dimensional solution structure of the calcium channel antagonist omega-agatoxin IVA: consensus molecular folding of calcium channel blockers. PUBMED:7623383 EPMC:7623383

External database links

This tab holds annotation information from the InterPro database.

InterPro entry IPR004169

This family contains spider toxins that include the omega-Aga-IVB, a P-type calcium channel antagonist from venom of the funnel web spider, Agelenopsis aperta [ PUBMED:8241166 , PUBMED:8232218 ], as well as purotoxin-1 (PT1), a spider peptide venom of the Central Asian spider Geolycosa sp., which specifically exerts inhibitory action on P2X3 purinoreceptors at nanomolar concentrations [ PUBMED:20437566 ]. These spider toxins, which are ion channel blockers, share a common structural motif composed of a triple-stranded antiparallel beta-sheet, stabilized by internal disulfide bonds known as cystine knots [ PUBMED:7703698 ].

Gene Ontology

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Domain organisation

Below is a listing of the unique domain organisations or architectures in which this domain is found. More...

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Pfam Clan

This family is a member of clan Omega_toxin (CL0083), which has the following description:

This clan contains a set of related small protein toxins and what appears to be the functionally distinct Albumin I domain. All members of this clan have a knottin-like fold. Additional information about this clan may be found from [1].

The clan contains the following 36 members:

ACI44 Agouti Albumin_I Albumin_I_a Antifungal_pept Antimicrobial25 Argos Atracotoxin CART CBM_1 Chi-conotoxin Conotoxin DUF5637 LEAP-2 Mu-conotoxin Omega-toxin Tachystatin_A Tachystatin_B Toxin_11 Toxin_12 Toxin_16 Toxin_18 Toxin_20 Toxin_21 Toxin_22 Toxin_23 Toxin_24 Toxin_27 Toxin_28 Toxin_30 Toxin_35 Toxin_7 Toxin_9 Tryp_inh UPF0506 Viral_cys_rich


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Curation and family details

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Seed source: Homstrad
Previous IDs: spidertoxin;
Type: Family
Sequence Ontology: SO:0100021
Author: Griffiths-Jones SR
Number in seed: 6
Number in full: 33
Average length of the domain: 38.70 aa
Average identity of full alignment: 58 %
Average coverage of the sequence by the domain: 32.88 %

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HMM build commands:
build method: hmmbuild -o /dev/null HMM SEED
search method: hmmsearch -Z 57096847 -E 1000 --cpu 4 HMM pfamseq
Model details:
Parameter Sequence Domain
Gathering cut-off 21.3 21.3
Trusted cut-off 21.3 21.4
Noise cut-off 21.2 21.2
Model length: 44
Family (HMM) version: 17
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Species distribution

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Archea Archea Eukaryota Eukaryota
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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 Toxin_9 domain has been found. There are 7 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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