UniProtKB - Q9TXD1 (KAX24_CENNO)
Protein
Potassium channel toxin alpha-KTx 2.4
Gene
N/A
Organism
Centruroides noxius (Mexican scorpion)
Status
Functioni
Blocks voltage-gated non-inactivating potassium channels (Kv) and unblocks inactivating potassium channels blocked by alpha-dendrotoxin in synaptosomes. It is not toxic to mice and crustaceans, but has a paralysing effect on crickets.1 Publication
Miscellaneous
NTX2 has a thousandfold less affinity than NTX, for the potassium channels (Kv) of synaptosomes. In addition, it shows a lower potency (over two logarithm units) than noxiustoxin (AC P08815) in producing 50% blockade of the probability of opening small conductance calcium-activated potassium (KCa) (obtained from cultured bovine aortic endothelial cells).1 Publication
Sites
Feature key | Position(s) | DescriptionActions | Graphical view | Length |
---|---|---|---|---|
Sitei | 27 | Basic residue of the functional dyadBy similarity | 1 | |
Sitei | 36 | Aromatic residue of the functional dyadBy similarity | 1 |
GO - Molecular functioni
- ion channel inhibitor activity Source: InterPro
- toxin activity Source: UniProtKB-KW
Keywordsi
Molecular function | Ion channel impairing toxin, Neurotoxin, Potassium channel impairing toxin, Toxin, Voltage-gated potassium channel impairing toxin |
Names & Taxonomyi
Protein namesi | Recommended name: Potassium channel toxin alpha-KTx 2.4Alternative name(s): Noxiustoxin-21 Publication Short name: NTx21 Publication |
Organismi | Centruroides noxius (Mexican scorpion) |
Taxonomic identifieri | 6878 [NCBI] |
Taxonomic lineagei | Eukaryota › Metazoa › Ecdysozoa › Arthropoda › Chelicerata › Arachnida › Scorpiones › Buthida › Buthoidea › Buthidae › Centruroides |
Subcellular locationi
Extracellular region or secreted
- Secreted 1 Publication
Extracellular region or secreted
- extracellular region Source: UniProtKB-SubCell
Keywords - Cellular componenti
SecretedPTM / Processingi
Molecule processing
Feature key | Position(s) | DescriptionActions | Graphical view | Length |
---|---|---|---|---|
PeptideiPRO_0000044906 | 1 – 38 | Potassium channel toxin alpha-KTx 2.41 PublicationAdd BLAST | 38 |
Amino acid modifications
Feature key | Position(s) | DescriptionActions | Graphical view | Length |
---|---|---|---|---|
Disulfide bondi | 7 ↔ 28 | By similarity | ||
Disulfide bondi | 13 ↔ 33 | By similarity | ||
Disulfide bondi | 17 ↔ 35 | By similarity |
Keywords - PTMi
Disulfide bondExpressioni
Tissue specificityi
Expressed by the venom gland.1 Publication
Structurei
3D structure databases
ProteinModelPortali | Q9TXD1 |
SMRi | Q9TXD1 |
ModBasei | Search... |
MobiDBi | Search... |
Family & Domainsi
Domaini
Has the structural arrangement of an alpha-helix connected to a beta-sheet by disulfide bonds (CSalpha/beta).By similarity
The N-terminus is probably essential for channel affinity.1 Publication
Sequence similaritiesi
Belongs to the short scorpion toxin superfamily. Potassium channel inhibitor family. Alpha-KTx 02 subfamily.Curated
Family and domain databases
Gene3Di | 3.30.30.10, 1 hit |
InterProi | View protein in InterPro IPR036574 Scorpion_toxin-like_sf IPR001947 Scorpion_toxinS_K_inh |
Pfami | View protein in Pfam PF00451 Toxin_2, 1 hit |
PRINTSi | PR00286 CHARYBDTOXIN |
ProDomi | View protein in ProDom or Entries sharing at least one domain PD003586 Scorpion_toxinS, 1 hit |
SUPFAMi | SSF57095 SSF57095, 1 hit |
PROSITEi | View protein in PROSITE PS01138 SCORP_SHORT_TOXIN, 1 hit |
i Sequence
Sequence statusi: Complete.
Similar proteinsi
Cross-referencesi
3D structure databases
ProteinModelPortali | Q9TXD1 |
SMRi | Q9TXD1 |
ModBasei | Search... |
MobiDBi | Search... |
Protocols and materials databases
Structural Biology Knowledgebase | Search... |
Family and domain databases
Gene3Di | 3.30.30.10, 1 hit |
InterProi | View protein in InterPro IPR036574 Scorpion_toxin-like_sf IPR001947 Scorpion_toxinS_K_inh |
Pfami | View protein in Pfam PF00451 Toxin_2, 1 hit |
PRINTSi | PR00286 CHARYBDTOXIN |
ProDomi | View protein in ProDom or Entries sharing at least one domain PD003586 Scorpion_toxinS, 1 hit |
SUPFAMi | SSF57095 SSF57095, 1 hit |
PROSITEi | View protein in PROSITE PS01138 SCORP_SHORT_TOXIN, 1 hit |
ProtoNeti | Search... |
Entry informationi
Entry namei | KAX24_CENNO | |
Accessioni | Q9TXD1Primary (citable) accession number: Q9TXD1 | |
Entry historyi | Integrated into UniProtKB/Swiss-Prot: | September 26, 2003 |
Last sequence update: | May 1, 2000 | |
Last modified: | November 22, 2017 | |
This is version 64 of the entry and version 1 of the sequence. See complete history. | ||
Entry statusi | Reviewed (UniProtKB/Swiss-Prot) | |
Annotation program | Animal Toxin Annotation Program |
Miscellaneousi
Keywords - Technical termi
Direct protein sequencingDocuments
- Scorpion potassium channel toxins
Nomenclature of scorpion potassium channel toxins and list of entries - SIMILARITY comments
Index of protein domains and families