We will be switching to the new UniProt website on Tuesday, June 28. Please explore and share your feedback.
Take me to UniProt BETA
UniProtKB - P17728 (SCXA_LEIHE)
Protein
Alpha-insect toxin LqhaIT
Gene
N/A
Organism
Leiurus hebraeus (Deathstalker scorpion) (Leiurus quinquestriatus hebraeus)
Status
Functioni
Alpha toxins bind voltage-independently at site-3 of sodium channels (Nav) and inhibit the inactivation of the activated channels, thereby blocking neuronal transmission. The dissociation is voltage-dependent. This toxin is active on insects. It is also highly toxic to crustaceans and has a measurable but low toxicity to mice.
Miscellaneous
The binding sites for this contractive toxin differ from those shared by the excitatory and depressant insect toxins.
Caution
The mutagenesis studies described in PubMed:8756487 and PubMed:9169449 are made with the sequence from PubMed:2383565 (see the sequence conflict in position 83-85).Curated
GO - Molecular functioni
- sodium channel inhibitor activity Source: InterPro
- toxin activity Source: UniProtKB-KW
GO - Biological processi
- defense response Source: InterPro
- modulation by symbiont of host nervous system process Source: InterPro
Keywordsi
Molecular function | Ion channel impairing toxin, Neurotoxin, Toxin, Voltage-gated sodium channel impairing toxin |
Names & Taxonomyi
Protein namesi | Recommended name: Alpha-insect toxin LqhaITAlternative name(s): Lqh-alpha-IT Short name: Alpha-IT |
Organismi | Leiurus hebraeus (Deathstalker scorpion) (Leiurus quinquestriatus hebraeus) |
Taxonomic identifieri | 6884 [NCBI] |
Taxonomic lineagei | Eukaryota › Metazoa › Ecdysozoa › Arthropoda › Chelicerata › Arachnida › Scorpiones › Buthida › Buthoidea › Buthidae › Leiurus › |
Subcellular locationi
Extracellular region or secreted
Extracellular region or secreted
- extracellular region Source: UniProtKB-SubCell
Keywords - Cellular componenti
SecretedPathology & Biotechi
Toxic dosei
LD50 is 250 µg/kg by subcutaneous injection to mice.1 Publication
Mutagenesis
Feature key | Position(s) | DescriptionActions | Graphical view | Length |
---|---|---|---|---|
Mutagenesisi | 27 | K → A: 74% loss of toxicity and 39.4-fold decrease in affinity to cockroach neuronal receptor. 1 Publication | 1 | |
Mutagenesisi | 27 | K → D: 99.4% loss of toxicity and 1611-fold decrease in affinity to cockroach neuronal receptor. 95% loss of toxicity and 71.4-fold decrease in affinity to cockroach neuronal receptor; when associated with A-34. 99.6% loss of toxicity and 21303-fold decrease in affinity to cockroach neuronal receptor; when associated with D-28 and V-29. 1 Publication | 1 | |
Mutagenesisi | 28 | N → D: 99.6% loss of toxicity and 21303-fold decrease in affinity to cockroach neuronal receptor; when associated with D-27 and V-29. | 1 | |
Mutagenesisi | 29 | Y → S: 90% loss of toxicity and 114.3-fold decrease in affinity to cockroach neuronal receptor. 1 Publication | 1 | |
Mutagenesisi | 29 | Y → V: 99.6% loss of toxicity and 21303-fold decrease in affinity to cockroach neuronal receptor; when associated with D-27 and D-28. 1 Publication | 1 | |
Mutagenesisi | 29 | Y → W: 57% loss of toxicity and 3.7-fold decrease in affinity to cockroach neuronal receptor. 1 Publication | 1 | |
Mutagenesisi | 34 | E → A: 77% loss of toxicity and 0.6-fold decrease in affinity to cockroach neuronal receptor; 95% loss of toxicity and 71.4-fold decrease in affinity to cockroach neuronal receptor; when associated with D-27. 1 Publication | 1 | |
Mutagenesisi | 36 | F → G: 86% loss of toxicity and 160-fold decrease in affinity to cockroach neuronal receptor. 1 Publication | 1 | |
Mutagenesisi | 37 | R → A: 78% loss of toxicity and 231.4-fold decrease in affinity to cockroach neuronal receptor. 1 Publication | 1 | |
Mutagenesisi | 37 | R → K: 59% loss of toxicity and 0.46-fold decrease in affinity to cockroach neuronal receptor; when associated with N-38. 1 Publication | 1 | |
Mutagenesisi | 38 | D → H: 75% loss of toxicity and 6-fold decrease in affinity to cockroach neuronal receptor. 1 Publication | 1 | |
Mutagenesisi | 38 | D → N: 15% increase in toxicity and 1.2-fold decrease in affinity to cockroach neuronal receptor; 59% loss of toxicity and 0.46-fold decrease in affinity to cockroach neuronal receptor; when associated with K-37. 1 Publication | 1 | |
Mutagenesisi | 59 | G → S: 36% loss of toxicity and 25.7-fold decrease in affinity to cockroach neuronal receptor; when associated with P-60. | 1 | |
Mutagenesisi | 60 | K → P: 36% loss of toxicity and 25.7-fold decrease in affinity to cockroach neuronal receptor; when associated with S-59. | 1 | |
Mutagenesisi | 68 | Y → I: 20% loss of toxicity to mice and 1.18-fold decrease in affinity to locust synaptosomal membranes; when associated with K-69. 540% loss of toxicity to mice and 1.08-fold decrease in affinity to locust synaptosomal membranes; when associated with K-69 and K-73. 1 Publication | 1 | |
Mutagenesisi | 69 | A → K: 20% loss of toxicity to mice and 1.18-fold decrease in affinity to locust synaptosomal membranes; when associated with I-68. 540% loss of toxicity to mice and 1.08-fold decrease in affinity to locust synaptosomal membranes; when associated with I-68 and K-73. 1 Publication | 1 | |
Mutagenesisi | 73 | N → K: 540% loss of toxicity to mice and 1.08-fold decrease in affinity to locust synaptosomal membranes; when associated with I-68 and K-69. 1 Publication | 1 | |
Mutagenesisi | 81 | K → L: 81% loss of toxicity and 220-fold decrease in affinity to cockroach neuronal receptor. 1 Publication | 1 | |
Mutagenesisi | 84 | R → A: 47% decrease in toxicity and 54.3-fold decrease in affinity to cockroach neuronal receptor. 1 Publication | 1 | |
Mutagenesisi | 84 | R → D: 95% decrease in toxicity and 2394-fold decrease in affinity to cockroach neuronal receptor. 1 Publication | 1 | |
Mutagenesisi | 84 | R → H: 220% decrease in toxicity and 0.3-fold decrease in affinity to cockroach neuronal receptor. 1 Publication | 1 | |
Mutagenesisi | 84 | R → N: 6% increase in toxicity and 58.6-fold decrease in affinity to cockroach neuronal receptor. 1 Publication | 1 |
PTM / Processingi
Molecule processing
Feature key | Position(s) | DescriptionActions | Graphical view | Length |
---|---|---|---|---|
Signal peptidei | 1 – 19 | 1 PublicationAdd BLAST | 19 | |
ChainiPRO_0000035296 | 20 – 85 | Alpha-insect toxin LqhaITAdd BLAST | 66 |
Amino acid modifications
Feature key | Position(s) | DescriptionActions | Graphical view | Length |
---|---|---|---|---|
Disulfide bondi | 31 ↔ 82 | PROSITE-ProRule annotation1 Publication | ||
Disulfide bondi | 35 ↔ 55 | PROSITE-ProRule annotation1 Publication | ||
Disulfide bondi | 41 ↔ 65 | PROSITE-ProRule annotation1 Publication | ||
Disulfide bondi | 45 ↔ 67 | PROSITE-ProRule annotation1 Publication |
Keywords - PTMi
Disulfide bondExpressioni
Tissue specificityi
Expressed by the venom gland.
Structurei
Secondary structure
Legend: HelixTurnBeta strandPDB Structure known for this area
Show more details3D structure databases
AlphaFoldDBi | P17728 |
SMRi | P17728 |
ModBasei | Search... |
PDBe-KBi | Search... |
Miscellaneous databases
EvolutionaryTracei | P17728 |
Family & Domainsi
Domains and Repeats
Feature key | Position(s) | DescriptionActions | Graphical view | Length |
---|---|---|---|---|
Domaini | 21 – 83 | LCN-type CS-alpha/betaPROSITE-ProRule annotationAdd BLAST | 63 |
Domaini
Has the structural arrangement of an alpha-helix connected to antiparallel beta-sheets by disulfide bonds (CS-alpha/beta).Curated
Sequence similaritiesi
Belongs to the long (4 C-C) scorpion toxin superfamily. Sodium channel inhibitor family. Alpha subfamily.Curated
Keywords - Domaini
SignalFamily and domain databases
CDDi | cd00107, Knot1, 1 hit |
Gene3Di | 3.30.30.10, 1 hit |
InterProi | View protein in InterPro IPR044062, LCN-type_CS_alpha_beta_dom IPR003614, Scorpion_toxin-like IPR036574, Scorpion_toxin-like_sf IPR018218, Scorpion_toxinL IPR002061, Scorpion_toxinL/defensin |
Pfami | View protein in Pfam PF00537, Toxin_3, 1 hit |
PRINTSi | PR00285, SCORPNTOXIN |
SMARTi | View protein in SMART SM00505, Knot1, 1 hit |
SUPFAMi | SSF57095, SSF57095, 1 hit |
PROSITEi | View protein in PROSITE PS51863, LCN_CSAB, 1 hit |
i Sequence
Sequence statusi: Complete.
: The displayed sequence is further processed into a mature form. Sequence processingi
P17728-1 [UniParc]FASTAAdd to basket
10 20 30 40 50
MNHLVMISLA LLLLLGVESV RDAYIAKNYN CVYECFRDAY CNELCTKNGA
60 70 80
SSGYCQWAGK YGNACWCYAL PDNVPIRVPG KCHRK
Experimental Info
Feature key | Position(s) | DescriptionActions | Graphical view | Length |
---|---|---|---|---|
Sequence conflicti | 83 – 85 | HRK → R AA sequence (PubMed:2383565).Curated | 3 |
Sequence databases
PIRi | A39306 |
Similar proteinsi
Cross-referencesi
Sequence databases
PIRi | A39306 |
3D structure databases
Select the link destinations: PDBei RCSB PDBi PDBji Links Updated | PDB entry | Method | Resolution (Å) | Chain | Positions | PDBsum |
1LQH | NMR | - | A | 20-82 | [»] | |
1LQI | NMR | - | A | 20-82 | [»] | |
2ASC | X-ray | 1.10 | A | 20-82 | [»] | |
2ATB | X-ray | 1.60 | A/B | 20-82 | [»] | |
2YEO | X-ray | 1.08 | A | 20-82 | [»] | |
AlphaFoldDBi | P17728 | |||||
SMRi | P17728 | |||||
ModBasei | Search... | |||||
PDBe-KBi | Search... |
Miscellaneous databases
EvolutionaryTracei | P17728 |
Family and domain databases
CDDi | cd00107, Knot1, 1 hit |
Gene3Di | 3.30.30.10, 1 hit |
InterProi | View protein in InterPro IPR044062, LCN-type_CS_alpha_beta_dom IPR003614, Scorpion_toxin-like IPR036574, Scorpion_toxin-like_sf IPR018218, Scorpion_toxinL IPR002061, Scorpion_toxinL/defensin |
Pfami | View protein in Pfam PF00537, Toxin_3, 1 hit |
PRINTSi | PR00285, SCORPNTOXIN |
SMARTi | View protein in SMART SM00505, Knot1, 1 hit |
SUPFAMi | SSF57095, SSF57095, 1 hit |
PROSITEi | View protein in PROSITE PS51863, LCN_CSAB, 1 hit |
MobiDBi | Search... |
Entry informationi
Entry namei | SCXA_LEIHE | |
Accessioni | P17728Primary (citable) accession number: P17728 | |
Entry historyi | Integrated into UniProtKB/Swiss-Prot: | August 1, 1990 |
Last sequence update: | March 1, 1992 | |
Last modified: | May 25, 2022 | |
This is version 126 of the entry and version 2 of the sequence. See complete history. | ||
Entry statusi | Reviewed (UniProtKB/Swiss-Prot) | |
Annotation program | Animal Toxin Annotation Program |
Miscellaneousi
Keywords - Technical termi
3D-structure, Direct protein sequencingDocuments
- PDB cross-references
Index of Protein Data Bank (PDB) cross-references - SIMILARITY comments
Index of protein domains and families