P81439 (EQST_ACTEQ) Reviewed, UniProtKB/Swiss-Prot

Names and origin

Protein names	Recommended name: Equistatin
Organism	Actinia equina (Beadlet anemone)
Taxonomic identifier	6106 [NCBI]
Taxonomic lineage	cellular organisms › Eukaryota › Opisthokonta › Metazoa › Eumetazoa › Cnidaria › Anthozoa › Hexacorallia › Actiniaria › Nynantheae › Actiniidae › Actinia

Protein attributes

Sequence length	199 AA.
Sequence status	Complete.
Protein existence	Evidence at protein level

General annotation (Comments)

Function	Potent inhibitor of papain-like cysteine proteinases.
Subcellular location	Secreted.
Sequence similarities	Belongs to the protease inhibitor I31 family. [View classification] Contains 3 thyroglobulin type-1 domains.

Ontologies

Keywords
Cellular component	Secreted
Domain	Repeat
Molecular function	Protease inhibitor Thiol protease inhibitor
PTM	Disulfide bond
Technical term	Direct protein sequencing
Gene Ontology (GO)
Cellular_component	extracellular region Inferred from electronic annotation. Source: UniProtKB-SubCell
Molecular_function	cysteine-type endopeptidase 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 – 199	199	Equistatin		PRO_0000195900
Regions
	Domain	2 – 63	62	Thyroglobulin type-1 1
	Domain	70 – 131	62	Thyroglobulin type-1 2
	Domain	135 – 199	65	Thyroglobulin type-1 3
Amino acid modifications
	Disulfide bond	5 ↔ 24		By similarity
	Disulfide bond	35 ↔ 42		By similarity
	Disulfide bond	44 ↔ 63		By similarity
	Disulfide bond	73 ↔ 92		By similarity
	Disulfide bond	103 ↔ 110		By similarity
	Disulfide bond	112 ↔ 131		By similarity
	Disulfide bond	138 ↔ 159		By similarity
	Disulfide bond	170 ↔ 177		By similarity
	Disulfide bond	179 ↔ 199		By similarity
Natural variations
	Natural variant	3	1	S → T.
	Natural variant	42	1	C → V.
	Natural variant	130	1	S → T.
	Natural variant	137	1	P → E.
	Natural variant	143 – 144	2	LQ → IK.
	Natural variant	156	1	V → L.
	Natural variant	184	1	G → D.

Sequences

	Sequence		Length	Mass (Da)
	P81439 [UniParc]. Last modified December 15, 1998. Version 1. Checksum: 87E44735F8171BFC	FASTA	199	21,755
	10 20 30 40 50 60 SLSKCQQLQA SANSGLIGAY VPQCKETGEF EEKQCWGSTG YCWCVDEDGK EILGTKIRGS 70 80 90 100 110 120 PDCSRRKAAL TLCQMMQAII VNVPGWCGPP SCKADGSFDE VQCCASNGEC YCVDKKGKEL 130 140 150 160 170 180 EGTRQKGRPS CERHLSPCEE ARLQAHSNSL RVGMFVPQCL EDGSYNPVQC WPSTGYCWCV 190 DEGGVKVPGS DVRFKRPTC

References

[1]	"Equistatin, a new inhibitor of cysteine proteinases from Actinia equina, is structurally related to thyroglobulin type-1 domain." Lenarcic B., Ritonja A., Strukelj B., Turk B., Turk V. J. Biol. Chem. 272:13899-13903(1997) [PubMed] [Europe PMC] [Abstract] Cited for: PROTEIN SEQUENCE.
[2]	Lenarcic B., Ritonja A., Strukelj B., Turk B., Turk V. J. Biol. Chem. 273:12682-12682(1998) Cited for: SEQUENCE REVISION.

Cross-references

3D structure databases
ProteinModelPortal	P81439.
ModBase	Search...
Protein family/group databases
MEROPS	I31.003.
Protocols and materials databases
StructuralBiologyKnowledgebase	Search...
Family and domain databases
Gene3D	4.10.800.10. 3 hits.
InterPro	IPR000716. Thyroglobulin_1. [Graphical view]
Pfam	PF00086. Thyroglobulin_1. 3 hits. [Graphical view]
SMART	SM00211. TY. 3 hits. [Graphical view]
SUPFAM	SSF57610. Thyroglobulin_1. 3 hits.
PROSITE	PS00484. THYROGLOBULIN_1_1. 2 hits. PS51162. THYROGLOBULIN_1_2. 3 hits. [Graphical view]
ProtoNet	Search...

Entry information

Entry name

EQST_ACTEQ

Accession

Primary (citable) accession number: P81439

Entry history

Integrated into UniProtKB/Swiss-Prot:	December 15, 1998
Last sequence update:	December 15, 1998
Last modified:	April 3, 2013
This is version 48 of the entry and version 1 of the sequence. [Complete history]

Entry status

Reviewed (UniProtKB/Swiss-Prot)