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Protein

M-theraphotoxin-Gr1a

Gene
N/A
Organism
Grammostola rosea (Chilean rose tarantula) (Grammostola spatulata)
Status
Reviewed-Annotation score: Annotation score: 4 out of 5-Experimental evidence at protein leveli

Functioni

This cationic hydrophobic peptide inhibits a lot of different channels and has an antimicrobial activity. It blocks mechanosensitive ion channels (also named stretch-activated channels or SACs), without having effect on whole-cell voltage-sensitive currents. Acts by partitioning into the membrane and perturbing the interface between the channel and the lipid bilayer without necessarily being in physical contact with the channel. Inhibits atrial fibrillation as well as the membrane motor of outer hair cells at low doses. It also binds to the voltage sensor of voltage-gated potassium channels from the archaebacterium Aeropyrum pernix (KvAP) without affecting channel gating. It has also a medium toxicity on a large spectra of sodium channels (Nav1.1/SCN1A, Nav1.2/SCN2A, Nav1.3/SCN3A, Nav1.4/SCN4A, Nav1.5/SCN5A, Nav1.6/SCN8A, Nav1.7/SCN9A), and also inhibits potassium channels Kv11.1/KCNH2 and Kv11.2/KCNH6. It also exhibits antimicrobial activities against the Gram-positive bacteria B.subtilis (MIC=0.5 µM), S.aureus (MIC=2-4 µM), and S.epidermidis (MIC=4-8 µM), and Gram-negative bacteria S.typhimurium (MIC=32.64 µM), P.aeruginosa (MIC=8-16 µM), and E.coli (MIC=8-16 µM).9 Publications

Miscellaneous

This toxin does not inhibit potassium channels Kv1.1/KCNA1 (IC50>85 µM), Kv1.4/KCNA4 (IC50>85 µM) and Kv11.3/KCNH7 (IC50=53 µM).

GO - Molecular functioni

GO - Biological processi

Keywordsi

Molecular functionAntibiotic, Antimicrobial, Ion channel impairing toxin, Potassium channel impairing toxin, Toxin, Voltage-gated potassium channel impairing toxin, Voltage-gated sodium channel impairing toxin

Names & Taxonomyi

Protein namesi
Recommended name:
M-theraphotoxin-Gr1a
Short name:
M-TRTX-Gr1a
Alternative name(s):
Toxin GsMTx-4
Short name:
GsMTx41 Publication
Short name:
MTx4
OrganismiGrammostola rosea (Chilean rose tarantula) (Grammostola spatulata)
Taxonomic identifieri432528 [NCBI]
Taxonomic lineageiEukaryotaMetazoaEcdysozoaArthropodaChelicerataArachnidaAraneaeMygalomorphaeTheraphosidaeGrammostola

Organism-specific databases

ArachnoServeriAS000068. M-theraphotoxin-Gr1a.

Subcellular locationi

GO - Cellular componenti

Keywords - Cellular componenti

Secreted

PTM / Processingi

Molecule processing

Feature keyPosition(s)DescriptionActionsGraphical viewLength
Signal peptidei1 – 21Sequence analysisAdd BLAST21
PropeptideiPRO_000003557522 – 464 PublicationsAdd BLAST25
ChainiPRO_000003557647 – 80M-theraphotoxin-Gr1aAdd BLAST34

Amino acid modifications

Feature keyPosition(s)DescriptionActionsGraphical viewLength
Disulfide bondi48 ↔ 632 PublicationsImported
Disulfide bondi55 ↔ 692 PublicationsImported
Disulfide bondi62 ↔ 762 PublicationsImported
Modified residuei80Phenylalanine amide2 Publications1

Keywords - PTMi

Amidation, Disulfide bond

Expressioni

Tissue specificityi

Expressed by the venom gland.

Structurei

Secondary structure

182
Legend: HelixTurnBeta strandPDB Structure known for this area
Show more details
Feature keyPosition(s)DescriptionActionsGraphical viewLength
Beta strandi51 – 54Combined sources4
Turni57 – 59Combined sources3
Beta strandi64 – 70Combined sources7
Turni71 – 74Combined sources4
Beta strandi75 – 78Combined sources4

3D structure databases

Select the link destinations:
PDBei
RCSB PDBi
PDBji
Links Updated
PDB entryMethodResolution (Å)ChainPositionsPDBsum
1LU8NMR-A47-80[»]
1TYKNMR-A47-80[»]
ProteinModelPortaliQ7YT39.
SMRiQ7YT39.
ModBaseiSearch...
MobiDBiSearch...

Miscellaneous databases

EvolutionaryTraceiQ7YT39.

Family & Domainsi

Domaini

The presence of a 'disulfide through disulfide knot' structurally defines this protein as a knottin.

Sequence similaritiesi

Belongs to the huwentoxin-1 family. MTx4 subfamily.Curated

Keywords - Domaini

Knottin, Signal

Family and domain databases

InterProiView protein in InterPro
IPR011696. Huwentoxin-1.
PfamiView protein in Pfam
PF07740. Toxin_12. 1 hit.

Sequencei

Sequence statusi: Complete.

Sequence processingi: The displayed sequence is further processed into a mature form.

Q7YT39-1 [UniParc]FASTAAdd to basket

« Hide

        10         20         30         40         50
MKTSVVFVIA GLALLSVVCY ASELKEQSSV NEVLSTIFHF EQPEERGCLE
60 70 80
FWWKCNPNDD KCCRPKLKCS KLFKLCNFSF GK
Length:82
Mass (Da):9,400
Last modified:October 1, 2003 - v1
Checksum:i1F92937F1D5DF979
GO

Experimental Info

Feature keyPosition(s)DescriptionActionsGraphical viewLength
Sequence conflicti80F → S AA sequence (PubMed:10779316).Curated1
Sequence conflicti80F → S AA sequence (Ref. 4) Curated1
Sequence conflicti81G → A AA sequence (PubMed:12082099).Curated1

Mass spectrometryi

Molecular mass is 4093.9 Da from positions 47 - 81. Determined by MALDI. 1 Publication

Sequence databases

Select the link destinations:
EMBLi
GenBanki
DDBJi
Links Updated
AY316118 mRNA. Translation: AAP79435.1.
PIRiA59371.

Similar proteinsi

Entry informationi

Entry nameiMTX4_GRARO
AccessioniPrimary (citable) accession number: Q7YT39
Secondary accession number(s): Q7M3T1
Entry historyiIntegrated into UniProtKB/Swiss-Prot: January 16, 2004
Last sequence update: October 1, 2003
Last modified: July 5, 2017
This is version 78 of the entry and version 1 of the sequence. See complete history.
Entry statusiReviewed (UniProtKB/Swiss-Prot)
Annotation programAnimal Toxin Annotation Program

Miscellaneousi

Keywords - Technical termi

3D-structure, Direct protein sequencing

Documents

  1. PDB cross-references
    Index of Protein Data Bank (PDB) cross-references
  2. SIMILARITY comments
    Index of protein domains and families