P81744 (TOG3B_AGEAP) Reviewed, UniProtKB/Swiss-Prot

Names and origin

Protein names	Recommended name: Omega-agatoxin-Aa3b Short name=Omega-AGTX-Aa3b Alternative name(s): Omega-agatoxin IIIB Short name=Omega-Aga-IIIB Omega-agatoxin-3B
Organism	Agelenopsis aperta (North American funnel-web spider) (Agelenopsis gertschi)
Taxonomic identifier	6908 [NCBI]
Taxonomic lineage	cellular organisms › Eukaryota › Opisthokonta › Metazoa › Eumetazoa › Bilateria › Protostomia › Ecdysozoa › Panarthropoda › Arthropoda › Chelicerata › Arachnida › Araneae › Araneomorphae › Entelegynae › RTA clade › Agelenidae › Agelenopsis

Protein attributes

Sequence length	76 AA.
Sequence status	Complete.
Protein existence	Evidence at protein level

General annotation (Comments)

Function	Omega-agatoxins are antagonists of voltage-gated calcium channels. This toxin blocks calcium channels in insect central neurons but not at peripheral neuromuscular junctions. In vertebrates, it is broadly active against all high-threshold Cav1/CACNA1 channels and Cav2.2/CACNA1B channels. Ref.1
Subcellular location	Secreted.
Tissue specificity	Expressed by the venom gland.
Domain	The presence of a 'disulfide through disulfide knot' structurally defines this protein as a knottin Probable.
Miscellaneous	This toxin does not inhibit Cav3 (T-type) channels.
Sequence similarities	Belongs to the omega-agatoxin superfamily. Type II/III omega-agatoxin family.

Ontologies

Keywords
Cellular component	Secreted
Domain	Knottin
Molecular function	Calcium channel inhibitor Ion channel impairing toxin Neurotoxin Presynaptic neurotoxin Toxin
PTM	Disulfide bond
Technical term	Direct protein sequencing
Gene Ontology (GO)
Cellular_component	other organism presynaptic membrane Inferred from electronic annotation. Source: UniProtKB-KW
Molecular_function	calcium 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
	Chain	1 – 76	76	Omega-agatoxin-Aa3b		PRO_0000087607
Amino acid modifications
	Disulfide bond	2 ↔ 19		Probable
	Disulfide bond	9 ↔ 25		Probable
	Disulfide bond	16 ↔ 52		Probable
	Disulfide bond	18 ↔ 40		Probable
	Disulfide bond	27 ↔ 38		Probable
	Disulfide bond	59 ↔ 67		Probable
Natural variations
	Natural variant	29	1	N → S. Ref.1
	Natural variant	35	1	K → R. Ref.1

Sequences

	Sequence		Length	Mass (Da)
	P81744 [UniParc]. Last modified June 1, 2001. Version 1. Checksum: D5C63C3AE8C95BB8	FASTA	76	8,620
	10 20 30 40 50 60 SCIDFGGDCD GEKDDCQCCR SNGYCSCYNL FGYLKSGCKC EVGTSAEFRR ICRRKAKQCY 70 NSDPDKCVSV YKPKRR

References

[1]

"Type III omega-agatoxins: a family of probes for similar binding sites on L- and N-type calcium channels." Ertel E.A., Warren V.A., Adams M.E., Griffin P.R., Cohen C.J., Smith M.M. Biochemistry 33:5098-5108(1994) [PubMed] [Europe PMC] [Abstract] Cited for: PROTEIN SEQUENCE, VARIANTS SER-29 AND ARG-35, FUNCTION. Tissue: Venom.

Cross-references

Sequence databases
PIR	B54252. C54252. D54252.
3D structure databases
ModBase	Search...
Protocols and materials databases
StructuralBiologyKnowledgebase	Search...
Organism-specific databases
ArachnoServer	AS000179. omega-agatoxin-Aa3b.
Family and domain databases
InterPro	IPR005853. Omega-agatoxin_II/III_CS. IPR013605. Toxin_34. [Graphical view]
Pfam	PF08396. Toxin_34. 1 hit. [Graphical view]
PROSITE	PS60023. OMEGA_AGA_II_III. 1 hit. [Graphical view]
ProtoNet	Search...

Entry information

Entry name

TOG3B_AGEAP

Accession

Primary (citable) accession number: P81744

Entry history

Integrated into UniProtKB/Swiss-Prot:	June 1, 2001
Last sequence update:	June 1, 2001
Last modified:	April 3, 2013
This is version 51 of the entry and version 1 of the sequence. [Complete history]

Entry status

Reviewed (UniProtKB/Swiss-Prot)

Annotation program

Animal Toxin Annotation Program