Reviewed, UniProtKB/Swiss-Prot P0C182 (KAX1B_CENNO)

Names and origin

Protein names	Recommended name:     Potassium channel toxin alpha-KTx 1.11 Alternative name(s):     Slotoxin       Short name=SloTx
Organism	Centruroides noxius (Mexican scorpion)
Taxonomic identifier	6878 [NCBI]
Taxonomic lineage	Eukaryota › Metazoa › Arthropoda › Chelicerata › Arachnida › Scorpiones › Buthida › Buthoidea › Buthidae › Centruroides

Protein attributes

Sequence length	37 AA.
Sequence status	Complete.
Sequence processing	The displayed sequence is not processed.
Protein existence	Evidence at protein level.

General annotation (Comments)

Function	Reversibly blocks the high conductance calcium-activated potassium channels composed of only alpha subunits (KCNMA1 = Slo1). Unreversibly blocks the high conductance calcium-activated potassium channels composed of alpha and beta1 subunits (KCNMA1 and KCNMB1). Unreversibly and weakly blocks the high conductance calcium-activated potassium channels composed of alpha and beta4 (KCNMA1 and KCNMB4). No activity on other potassium channels such as slo, KCNA1, KCNH2, KCNJ12, Shaker-IR, nor voltage-independent/calcium-activated SK1, SK2 and SK3. Ref.1
Subcellular location	Secreted.
Tissue specificity	Expressed by the venom gland.
Sequence similarities	Belongs to the short scorpion toxin superfamily. Potassium channel inhibitor family. Alpha-KTx 1 subfamily.
Mass spectrometry	Molecular mass is 4082.82 Da from positions 1 - 37. Ref.1

Ontologies

Keywords
Cellular component	Secreted
Molecular function	Ionic channel inhibitor Neurotoxin Potassium channel inhibitor Toxin
PTM	Disulfide bond Pyrrolidone carboxylic acid
Technical term	Direct protein sequencing
Gene Ontology (GO)
Biological process	pathogenesis Inferred from electronic annotation. Source: UniProtKB-KW
Cellular component	extracellular region Inferred from electronic annotation. Source: UniProtKB-SubCell
Molecular function	potassium 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 – 37	37	Potassium channel toxin alpha-KTx 1.11		PRO_0000228823
Amino acid modifications
	Disulfide bond	7 ↔ 28		By similarity
	Disulfide bond	13 ↔ 33		By similarity
	Disulfide bond	17 ↔ 35		By similarity

Sequences

	Sequence		Length	Mass (Da)
	P0C182-1 [UniParc]. Last modified March 21, 2006. Version 1. Checksum: 87352585F8F85028	FASTA	37	4,092
	10 20 30 TFIDVDCTVS KECWAPCKAA FGVDRGKCMG KKCKCYV

References

[1]	"Slotoxin, alphaKTx1.11, a new scorpion peptide blocker of MaxiK channels that differentiates between alpha and alpha+beta (beta1 or beta4) complexes." Garcia-Valdes J., Zamudio F.Z., Toro L., Possani L.D. FEBS Lett. 505:369-373(2001) [PubMed: 11576530] [Abstract] Cited for: PROTEIN SEQUENCE, FUNCTION, MASS SPECTROMETRY. Tissue: Venom.
[2]	Erratum Garcia-Valdes J., Zamudio F.Z., Toro L., Possani L.D. FEBS Lett. 507:122-122(2001)

Cross-references

3D structure databases
ModBase	Search...
Family and domain databases
InterPro	IPR001947. Scorpion_toxinS. [Graphical view]
Pfam	PF00451. Toxin_2. 1 hit. [Graphical view]
PRINTS	PR00286. CHARYBDTOXIN.
ProDom	PD003586. Scorpion_toxinS. 1 hit. [Graphical view] [Entries sharing at least one domain]
PROSITE	PS01138. SCORP_SHORT_TOXIN. 1 hit. [Graphical view]
ProtoNet	Search...

Entry information

Entry name

KAX1B_CENNO

Accession

Primary (citable) accession number: P0C182

Entry history

Integrated into UniProtKB/Swiss-Prot:	March 21, 2006
Last sequence update:	March 21, 2006
Last modified:	June 16, 2009
This is version 16 of the entry and version 1 of the sequence. [Complete history]

Entry status

Reviewed (UniProtKB/Swiss-Prot)

Annotation project

Tox-Prot (Toxin Annotation Project)