P01489 · SCX4_LEIQU
- ProteinAlpha-toxin Lqq4
- StatusUniProtKB reviewed (Swiss-Prot)
- Amino acids
- Protein existenceEvidence at protein level
- Annotation score5/5
Function
function
Alpha toxins bind voltage-independently at site-3 of sodium channels (Nav) and inhibit the inactivation of the activated channels, thereby blocking neuronal transmission. Both native and recombinant (non-amidated) toxins inhibit inactivation of Nav1.2/SCN2A (EC50=31.2-36.6 nM), Nav1.6/SCN8A (EC50=6.9-8.9 nM), and Nav1.7/SCN9A (EC50=182.0-260.1 nM).
Miscellaneous
Exists in 4 forms, due to cis-trans isomerization at 17-Cys-Gly-18 and 56-Val-Pro-57. The trans-C17-G18/trans-V56-P57 conformation form is the most abundant (46%), followed by trans-C17-G18/cis-V56-P57 (33%), cis-C17-G18/trans-V56-P57 (14%), and cis-C17-G18/cis-V56-P57 (7%).
GO annotations
all annotations | all molecular function | virus receptor activity | dna binding | rna binding | cytoskeletal motor activity | catalytic activity | gtpase activity | structural molecule activity | transporter activity | cytoskeletal protein binding | lipid binding | cyclase activity | antioxidant activity | oxidoreductase activity | transferase activity | hydrolase activity | lyase activity | isomerase activity | ligase activity | protein tag activity | cargo receptor activity | histone binding | protein folding chaperone | translation regulator activity | nutrient reservoir activity | receptor ligand activity | molecular transducer activity | molecular adaptor activity | toxin activity | cell adhesion mediator activity | molecular function regulator activity | virus coreceptor activity | catalytic activity, acting on a protein | catalytic activity, acting on dna | catalytic activity, acting on rna | molecular carrier activity | transcription regulator activity | general transcription initiation factor activity | molecular sensor activity | molecular sequestering activity | atp-dependent activity | other molecular function | all biological process | mitotic cell cycle | cytokinesis | cytoplasmic translation | immune system process | muscle system process | circulatory system process | renal system process | respiratory system process | carbohydrate metabolic process | generation of precursor metabolites and energy | dna replication | dna repair | dna recombination | chromatin organization | dna-templated transcription | regulation of dna-templated transcription | trna metabolic process | protein folding | protein glycosylation | amino acid metabolic process | modified amino acid metabolic process | lipid metabolic process | vitamin metabolic process | sulfur compound metabolic process | intracellular protein transport | nucleocytoplasmic transport | autophagy | inflammatory response | mitochondrion organization | cytoskeleton organization | microtubule-based movement | peroxisome organization | lysosome organization | chromosome segregation | cell adhesion | establishment or maintenance of cell polarity | programmed cell death | photosynthesis | mrna metabolic process | snrna metabolic process | vesicle-mediated transport | reproductive process | digestive system process | signaling | cell differentiation | protein catabolic process | extracellular matrix organization | regulatory ncrna-mediated gene silencing | telomere organization | cell junction organization | wound healing | ribosome biogenesis | cilium organization | anatomical structure development | cell motility | nervous system process | endocrine process | protein maturation | transmembrane transport | nucleobase-containing small molecule metabolic process | hepaticobiliary system process | membrane organization | protein-containing complex assembly | cell wall organization or biogenesis | nitrogen cycle metabolic process | protein localization to plasma membrane | defense response to other organism | detoxification | meiotic nuclear division | mitotic nuclear division | mitochondrial gene expression | carbohydrate derivative metabolic process | other biological process | all cellular component | nuclear chromosome | extracellular region | extracellular space | cell wall | nucleus | nuclear envelope | nucleoplasm | chromosome | nucleolus | mitochondrion | lysosome | endosome | vacuole | peroxisome | endoplasmic reticulum | golgi apparatus | lipid droplet | microtubule organizing center | cytosol | ribosome | cytoskeleton | plasma membrane | cilium | plastid | thylakoid | external encapsulating structure | extracellular matrix | cytoplasmic vesicle | organelle | other cellular component | |||
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Aspect | Term | |
---|---|---|
Cellular Component | extracellular region | |
Molecular Function | sodium channel inhibitor activity | |
Molecular Function | toxin activity | |
Biological Process | defense response |
Keywords
- Molecular function
Names & Taxonomy
Protein names
- Recommended nameAlpha-toxin Lqq4
- Alternative names
Organism names
- Taxonomic lineageEukaryota > Metazoa > Ecdysozoa > Arthropoda > Chelicerata > Arachnida > Scorpiones > Buthida > Buthoidea > Buthidae > Leiurus
Accessions
- Primary accessionP01489
Subcellular Location
PTM/Processing
Features
Showing features for chain, disulfide bond, modified residue.
Type | ID | Position(s) | Description | |||
---|---|---|---|---|---|---|
Chain | PRO_0000066781 | 1-65 | Alpha-toxin Lqq4 | |||
Sequence: GVRDAYIADDKNCVYTCGSNSYCNTECTKNGAESGYCQWLGKYGNACWCIKLPDKVPIRIPGKCR | ||||||
Disulfide bond | 13↔64 | |||||
Sequence: CVYTCGSNSYCNTECTKNGAESGYCQWLGKYGNACWCIKLPDKVPIRIPGKC | ||||||
Disulfide bond | 17↔37 | |||||
Sequence: CGSNSYCNTECTKNGAESGYC | ||||||
Disulfide bond | 23↔47 | |||||
Sequence: CNTECTKNGAESGYCQWLGKYGNAC | ||||||
Disulfide bond | 27↔49 | |||||
Sequence: CTKNGAESGYCQWLGKYGNACWC | ||||||
Modified residue | 65 | Arginine amide | ||||
Sequence: R |
Post-translational modification
The recombinant toxin which is used for activity tests is not amidated (PubMed:37501371).
However, C-terminal amidation does not appear to play an important role in activity, since the non-amidated recombinant toxin and the native toxin (which is amidated) show similar activities on all sodium channels tested
However, C-terminal amidation does not appear to play an important role in activity, since the non-amidated recombinant toxin and the native toxin (which is amidated) show similar activities on all sodium channels tested
Keywords
- PTM
Expression
Tissue specificity
Expressed by the venom gland.
Structure
Family & Domains
Features
Showing features for domain, region.
Type | ID | Position(s) | Description | |||
---|---|---|---|---|---|---|
Domain | 3-65 | LCN-type CS-alpha/beta | ||||
Sequence: RDAYIADDKNCVYTCGSNSYCNTECTKNGAESGYCQWLGKYGNACWCIKLPDKVPIRIPGKCR | ||||||
Region | 9-13 | Specificity module, loop 1 | ||||
Sequence: DDKNC | ||||||
Region | 40-44 | Specificity module, loop 2 | ||||
Sequence: LGKYG | ||||||
Region | 57-65 | Specificity module, loop 3 | ||||
Sequence: PIRIPGKCR |
Domain
Has the structural arrangement of an alpha-helix connected to antiparallel beta-sheets by disulfide bonds (CS-alpha/beta).
Sequence similarities
Belongs to the long (4 C-C) scorpion toxin superfamily. Sodium channel inhibitor family. Alpha subfamily.
Family and domain databases
Sequence
- Sequence statusComplete
- Length65
- Mass (Da)7,202
- Last updated1986-07-21 v1
- Checksum882102EC1C2B89F6
Mass Spectrometry
Keywords
- Technical term