Summary: Scorpion calcine family
The Pfam group coordinates the annotation of Pfam families in Wikipedia, but we have not yet assigned a Wikipedia article to this family. If you think that a particular Wikipedia article provides good annotation, please let us know.
This tab holds the annotation information that is stored in the Pfam database. As we move to using Wikipedia as our main source of annotation, the contents of this tab will be gradually replaced by the Wikipedia tab.
Scorpion calcine family Provide feedback
This family consists of the calcine family of scorpion toxins. The calcine family consists of Maurocalcine and Imperatoxin. These toxins have been shown to be potent effector of ryanodyne-sensitive calcium channel from skeletal muscles. These toxins are thus useful for dihydropyridine receptor/ryanodyne receptor interaction studies [1,2].
Mosbah A, Kharrat R, Fajloun Z, Renisio JG, Blanc E, Sabatier JM, El Ayeb M, Darbon H; , Proteins 2000;40:436-442.: A new fold in the scorpion toxin family, associated with an activity on a ryanodine-sensitive calcium channel. PUBMED:10861934 EPMC:10861934
Nabhani T, Zhu X, Simeoni I, Sorrentino V, Valdivia HH, Garcia J; , Biophys J 2002;82:1319-1328.: Imperatoxin a enhances Ca(2+) release in developing skeletal muscle containing ryanodine receptor type 3. PUBMED:11867448 EPMC:11867448
External database links
This tab holds annotation information from the InterPro database.
InterPro entry IPR012632
Toxins of the scorpion calcine family bind directly to ryanodine receptors (RyRs), intracellular channel targets of the endoplasmic reticulum, and induce long lasting channel openings in a mode of smaller conductance. They have the ability to translocate into cells by crossing the plasma membrane [PUBMED:10075681, PUBMED:10713267, PUBMED:15653689].
Toxins of scorpion calcine family are highly basic 33-amino acid peptides that present three disulphide bridges (C1-C4, C2-C5, and C3-C6) and fold along a knottin or inhibitor cystine knot motif (http://knottin.cbs.cnrs.fr) [PUBMED:10075681, PUBMED:10713267, PUBMED:15653689]. Their three dimensional structure consists of a compact disulphide-bonded core from which emerge loops and the N terminus. The main element of regular secondary structure is a double-stranded antiparallel beta-sheet. A third peripheral extended strand is almost perpendicular to the double-stranded antiparallel beta-sheet [PUBMED:10713267, PUBMED:10861934]. Scorpion calcine mimic the activating segment of the dihydropyridine receptor II-III loop, which interacts with a region of the ryanodine receptor [PUBMED:10075681, PUBMED:10713267, PUBMED:12429019].
This family includes:
- Imperatoxin-A (IpTx A) from Pandinus imperator (Emperor scorpion).
- Opicalcin-1 and -2 from Opistophthalmus carinatus (African yellow leg scorpion).
- Maurocalcin (MCa) from Scorpio maurus palmatus (Chactoid scorpion).
|Cellular component||extracellular region (GO:0005576)|
|Molecular function||calcium channel inhibitor activity (GO:0019855)|
|Biological process||pathogenesis (GO:0009405)|
- the number of sequences which exhibit this architecture
a textual description of the architecture, e.g. Gla, EGF x 2, Trypsin.
This example describes an architecture with one
Gladomain, followed by two consecutive
EGFdomains, and finally a single
- the UniProt description of the protein sequence
- the number of residues in the sequence
- the Pfam graphic itself.
Loading domain graphics...
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 .
The clan contains the following 19 members:Agouti Albumin_I Conotoxin Mu-conotoxin Omega-toxin Tachystatin_B Toxin_11 Toxin_12 Toxin_16 Toxin_18 Toxin_21 Toxin_22 Toxin_23 Toxin_24 Toxin_27 Toxin_30 Toxin_7 Toxin_9 UPF0506
We make a range of alignments for each Pfam-A family:
- the curated alignment from which the HMM for the family is built
- the alignment generated by searching the sequence database using the HMM
- Representative Proteomes (RPs) at 15%, 35%, 55% and 75% co-membership thresholds
- alignment generated by searching the NCBI sequence database using the family HMM
- alignment generated by searching the metagenomics sequence database using the family HMM
You can see the alignments as HTML or in three different sequence viewers:
- Pfam viewer
- an HTML-based viewer that uses DAS to retrieve alignment fragments on request
1Cannot generate PP/Heatmap alignments for seeds; no PP data available
Key: available, not generated, — not available.
Format an alignment
If you find these logos useful in your own work, please consider citing the following article:
Note: You can also download the data file for the tree.
Curation and family details
|Seed source:||Short protein clustering|
|Number in seed:||2|
|Number in full:||5|
|Average length of the domain:||33.00 aa|
|Average identity of full alignment:||83 %|
|Average coverage of the sequence by the domain:||60.66 %|
|HMM build commands:||
build method: hmmbuild -o /dev/null HMM SEED
search method: hmmsearch -Z 23193494 -E 1000 --cpu 4 HMM pfamseq
|Family (HMM) version:||6|
|Download:||download the raw HMM for this family|
Weight segments by...
Change the size of the sunburst
selected sequences to HMM
a FASTA-format file
- 0 sequences
- 0 species
How the sunburst is generated
Colouring and labels
Anomalies in the taxonomy tree
Missing taxonomic levels
Unmapped species names
Too many species/sequences
The tree shows the occurrence of this domain across different species. More...
You can use the tree controls to manipulate how the interactive tree is displayed:
- show/hide the summary boxes
- highlight species that are represented in the seed alignment
- expand/collapse the tree or expand it to a given depth
- select a sub-tree or a set of species within the tree and view them graphically or as an alignment
- save a plain text representation of the tree
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_27 domain has been found. There are 1 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 seqence.
Loading structure mapping...