P81761 (SCIT_MESTA) Reviewed, UniProtKB/Swiss-Prot

Names and origin

Protein names	Recommended name: Lepidopteran-selective toxin Alternative name(s): BTChl2 ButaIT
Organism	Mesobuthus tamulus (Eastern Indian scorpion) (Buthus tamulus)
Taxonomic identifier	34647 [NCBI]
Taxonomic lineage	cellular organisms › Eukaryota › Opisthokonta › Metazoa › Eumetazoa › Bilateria › Protostomia › Ecdysozoa › Panarthropoda › Arthropoda › Chelicerata › Arachnida › Scorpiones › Buthida › Buthoidea › Buthidae › Mesobuthus

Protein attributes

Sequence length	62 AA.
Sequence status	Complete.
Sequence processing	The displayed sequence is further processed into a mature form.
Protein existence	Evidence at protein level

General annotation (Comments)

Function	Blocks small-conductance chloride channels By similarity. Induces flaccid paralysis in H.virescens larvae. Is not toxic to S.falculata larvae or mice. Ref.2
Subcellular location	Secreted Ref.2.
Tissue specificity	Expressed by the venom gland. Ref.2
Domain	The presence of a 'disulfide through disulfide knot' structurally defines this protein as a knottin By similarity.
Sequence similarities	Belongs to the short scorpion toxin superfamily. Chloride channel inhibitor family.
Mass spectrometry	Molecular mass is 3856.7 Da from positions 25 - 61. Determined by ESI. Ref.2

Ontologies

Keywords
Cellular component	Secreted
Domain	Knottin Signal
Molecular function	Chloride channel inhibitor Ion channel impairing toxin Neurotoxin Toxin
PTM	Disulfide bond
Technical term	Direct protein sequencing
Gene Ontology (GO)
Biological_process	pathogenesis Inferred from direct assay Ref.2. Source: UniProtKB
Cellular_component	extracellular region Inferred from direct assay Ref.2. Source: UniProtKB
Molecular_function	chloride channel inhibitor activity Inferred from electronic annotation. Source: UniProtKB-KW potassium channel inhibitor activity Non-traceable author statement Ref.2. Source: UniProtKB
Complete GO annotation...

Sequence annotation (Features)

	Feature key	Position(s)	Length	Description	Graphical view	Feature identifier
Molecule processing
	Signal peptide	1 – 24	24	Ref.2
	Chain	25 – 61	37	Lepidopteran-selective toxin		PRO_0000035331
	Propeptide	62	1	Probable		PRO_0000035332
Amino acid modifications
	Disulfide bond	26 ↔ 43		By similarity
	Disulfide bond	29 ↔ 51		By similarity
	Disulfide bond	40 ↔ 56		By similarity
	Disulfide bond	44 ↔ 58		By similarity

Sequences

	Sequence		Length	Mass (Da)
	P81761 [UniParc]. Last modified September 26, 2003. Version 2. Checksum: 32E0B3AF2382597E	FASTA	62	6,656
	10 20 30 40 50 60 MKFLYGVILI ALFLTVMTAT LSEARCGPCF TTDPQTQAKC SECCGRKGGV CKGPQCICGI QY

References

[1]

"Insect toxin from Mesobuthus tamulus." Newton K.A., Armugam A., Strong P.N., Jeyaseelan K. Submitted (FEB-2002) to the EMBL/GenBank/DDBJ databases Cited for: NUCLEOTIDE SEQUENCE [MRNA]. Tissue: Venom gland.

[2]

"Isolation and characterization of a novel lepidopteran-selective toxin from the venom of South Indian red scorpion, Mesobuthus tamulus." Wudayagiri R., Inceoglu A.B., Herrmann R., Derbel M., Choudary P.V., Hammock B.D. BMC Biochem. 2:16-16(2001) [PubMed] [Europe PMC] [Abstract] Cited for: PROTEIN SEQUENCE OF 25-61, FUNCTION, SUBCELLULAR LOCATION, TISSUE SPECIFICITY, MASS SPECTROMETRY. Tissue: Venom.

Cross-references

Sequence databases
EMBL GenBank DDBJ	AF481881 mRNA. Translation: AAL87237.1.
3D structure databases
ProteinModelPortal	P81761.
SMR	P81761. Positions 26-59.
ModBase	Search...
Protocols and materials databases
StructuralBiologyKnowledgebase	Search...
Family and domain databases
InterPro	IPR003614. Scorpion_toxin-like. IPR007958. Scorpion_toxinS_Cl_inh. [Graphical view]
Pfam	PF05294. Toxin_5. 1 hit. [Graphical view]
SUPFAM	SSF57095. SSF57095. 1 hit.
PROSITE	PS51200. SHORT_SCORPION_CHLORIDE. 1 hit. [Graphical view]
ProtoNet	Search...

Entry information

Entry name

SCIT_MESTA

Accession

Primary (citable) accession number: P81761
Secondary accession number(s): Q8T0X4

Entry history

Integrated into UniProtKB/Swiss-Prot:	May 10, 2002
Last sequence update:	September 26, 2003
Last modified:	May 1, 2013
This is version 47 of the entry and version 2 of the sequence. [Complete history]

Entry status

Reviewed (UniProtKB/Swiss-Prot)

Annotation program

Animal Toxin Annotation Program