P08815 (KAX21_CENNO) Reviewed, UniProtKB/Swiss-Prot
Last modified
November 16, 2011.
Version 75.
History...
Names·Attributes·General annotation·Ontologies·Sequence annotation·Sequences·References·Cross-refs·Entry info·DocumentsCustomize order
Names·Attributes·General annotation·Ontologies·Sequence annotation·Sequences·References·Cross-refs·Entry info·DocumentsCustomize orderNames and origin
| Protein names | Recommended name: Potassium channel toxin alpha-KTx 2.1 Alternative name(s): Noxiustoxin Short name=NTx Toxin II.11 |
| Organism | Centruroides noxius (Mexican scorpion) |
| Taxonomic identifier | 6878 [NCBI] |
| Taxonomic lineage | Eukaryota › Metazoa › Arthropoda › Chelicerata › Arachnida › Scorpiones › Buthida › Buthoidea › Buthidae › Centruroides |
Protein attributes
| Sequence length | 39 AA. |
| Sequence status | Complete. |
| Protein existence | Evidence at protein level |
General annotation (Comments)
| Function | Blocks voltage-gated non-inactivating potassium channels and unblocks inactivating potassium channels blocked by alpha-dendrotoxin in synaptosomes. Also displaces the alpha-dendrotoxin homolog dendrotoxin I from its receptor on brain synaptic membranes. |
| Subcellular location | |
| Tissue specificity | Expressed by the venom gland. |
| Domain | The N-terminus is probably essential for channel affinity. |
| Miscellaneous | Is more effective than NTX2. |
| Sequence similarities | Belongs to the short scorpion toxin superfamily. Potassium channel inhibitor family. Alpha-KTx 2 subfamily. |
Ontologies
| Keywords | |
|---|---|
| Cellular component | Secreted |
| Molecular function | Ionic channel inhibitor Neurotoxin Potassium channel inhibitor Toxin |
| PTM | Amidation Disulfide bond |
| Technical term | 3D-structure Direct protein sequencing |
| Gene Ontology (GO) | |
| Biological process | pathogenesis Inferred from electronic annotation. Source: InterPro |
| Cellular component | extracellular region Inferred from electronic annotation. Source: UniProtKB-SubCell |
| Molecular function | potassium channel inhibitor activity Inferred from electronic annotation. Source: UniProtKB-KW |
| Complete GO annotation... | |
Sequence annotation (Features)
| Feature key | Position(s) | Length | Description | Graphical view | Feature identifier | |||||||||||
Molecule processing | ||||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Peptide | 1 – 39 | 39 | Potassium channel toxin alpha-KTx 2.1 | PRO_0000044905 | ||||||||||||
Regions | ||||||||||||||||
| Region | 26 – 34 | 9 | Interaction with Ca(2+)-activated K(+) channels Potential | |||||||||||||
Sites | ||||||||||||||||
| Site | 28 | 1 | Basic residue of the functional dyad By similarity | |||||||||||||
| Site | 37 | 1 | Aromatic residue of the functional dyad By similarity | |||||||||||||
Amino acid modifications | ||||||||||||||||
| Modified residue | 39 | 1 | Asparagine amide | |||||||||||||
| Disulfide bond | 7 ↔ 29 | Ref.4 | ||||||||||||||
| Disulfide bond | 13 ↔ 34 | Ref.4 | ||||||||||||||
| Disulfide bond | 17 ↔ 36 | Ref.4 | ||||||||||||||
Secondary structure | ||||||||||||||||
Helix Strand Turn | ||||||||||||||||
| Turn | 14 – 16 | 3 | ||||||||||||||
| Helix | 17 – 20 | 4 | ||||||||||||||
| Beta strand | 27 – 30 | 4 | ||||||||||||||
| Beta strand | 33 – 36 | 4 | ||||||||||||||
Sequences
References
| [1] | "The primary structure of noxiustoxin. A K channel blocking peptide, purified from the venom of the scorpion Centruroides noxius Hoffmann." Possani L.D., Martin B.M., Svendsen I. Carlsberg Res. Commun. 47:285-289(1982) Cited for: PROTEIN SEQUENCE. Tissue: Venom. |
| [2] | "Synthetic peptides corresponding to the sequence of noxiustoxin indicate that the active site of this K+ channel blocker is located on its amino-terminal portion." Gurrola G.B., Molinar-Rode R., Sitges M., Bayon A., Possani L.D. J. Neural Transm. 77:11-20(1989) [PubMed: 2746197] [Abstract] Cited for: SYNTHESIS OF 1-9 AND 30-39. |
| [3] | "Structure revision of the scorpion toxin noxiustoxin through total chemical synthesis." Nutt R.F., Arison B.H., Smith J.S. (In) Schneider C.H., Eberles A.N. (eds.); Peptides 1992, pp.101-102, Escom Science Publishers, Leiden (1993) Cited for: SYNTHESIS, AMIDATION. |
| [4] | "Determination of the three-dimensional solution structure of noxiustoxin: analysis of structural differences with related short-chain scorpion toxins." Dauplais M., Gilquin B., Possani L.D., Gurrola-Briones G., Roumestand C., Menez A. Biochemistry 34:16563-16573(1995) [PubMed: 8527429] [Abstract] Cited for: STRUCTURE BY NMR, DISULFIDE BONDS. |
Cross-references
3D structure databases | |||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| PDBe RCSB PDB PDBj |
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| ProteinModelPortal | P08815. | ||||||||||||
| SMR | P08815. Positions 1-39. | ||||||||||||
| ModBase | Search... | ||||||||||||
Protocols and materials databases | |||||||||||||
| StructuralBiologyKnowledgebase | Search... | ||||||||||||
Family and domain databases | |||||||||||||
| InterPro | IPR001947. Scorpion_toxinS. [Graphical view] | ||||||||||||
| Pfam | PF00451. Toxin_2. 1 hit. [Graphical view] | ||||||||||||
| PRINTS | PR00286. CHARYBDTOXIN. | ||||||||||||
| ProDom | PD003586. Scorpion_toxinS. 1 hit. [Graphical view] [Entries sharing at least one domain] | ||||||||||||
| PROSITE | PS01138. SCORP_SHORT_TOXIN. 1 hit. [Graphical view] | ||||||||||||
| ProtoNet | Search... | ||||||||||||
Entry information
| Entry name | KAX21_CENNO | ||||||||
| Accession | Primary (citable) accession number: P08815 | ||||||||
| Entry history |
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| Entry status | Reviewed (UniProtKB/Swiss-Prot) | ||||||||
| Annotation program | Animal Toxin Annotation Program | ||||||||
Relevant documents
| Scorpion potassium channel toxins Nomenclature of scorpion potassium channel toxins and list of entries |
| PDB cross-references Index of Protein Data Bank (PDB) cross-references |
| SIMILARITY comments Index of protein domains and families |

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