P16344 (ITR4_HETCR) Reviewed, UniProtKB/Swiss-Prot

Names and origin

Protein names	Recommended name: Kunitz-type trypsin inhibitor IV
Organism	Heteractis crispa (Leathery sea anemone) (Radianthus macrodactylus)
Taxonomic identifier	175771 [NCBI]
Taxonomic lineage	cellular organisms › Eukaryota › Opisthokonta › Metazoa › Eumetazoa › Cnidaria › Anthozoa › Hexacorallia › Actiniaria › Stichodactylidae › Heteractis

Protein attributes

Sequence length	56 AA.
Sequence status	Complete.
Protein existence	Evidence at protein level

General annotation (Comments)

Function	Inhibitor of trypsin.
Subcellular location	Secreted. Nematocyst.
Sequence similarities	Belongs to the cnidaria Kunitz-type proteinase inhibitor family. Contains 1 BPTI/Kunitz inhibitor domain.

Ontologies

Keywords
Cellular component	Nematocyst Secreted
Molecular function	Protease inhibitor Serine protease inhibitor
PTM	Disulfide bond
Technical term	Direct protein sequencing
Gene Ontology (GO)
Cellular_component	extracellular region Inferred from electronic annotation. Source: UniProtKB-SubCell nematocyst Inferred from electronic annotation. Source: UniProtKB-SubCell
Molecular_function	serine-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 – 56	56	Kunitz-type trypsin inhibitor IV		PRO_0000155418
Regions
	Domain	4 – 54	51	BPTI/Kunitz inhibitor
Sites
	Site	14 – 15	2	Reactive bond By similarity
Amino acid modifications
	Disulfide bond	4 ↔ 54		By similarity
	Disulfide bond	13 ↔ 37		By similarity
	Disulfide bond	29 ↔ 50		By similarity

Sequences

	Sequence		Length	Mass (Da)
	P16344 [UniParc]. Last modified August 1, 1990. Version 1. Checksum: 68374D2025B841C0	FASTA	56	6,172
	10 20 30 40 50 GSICLEPKVV GPCTAYFPRF YFDSETGKCT PFIYGGCEGN SYVDEKLHAC RAICRA

References

[1]	"Amino-acid sequence of trypsin inhibitor IV from Radiantis macrodactylus." Zykova T.A., Vinokurov L.M., Markova L.F., Kozlovskaya E.P., Elyakov G.B. Bioorg. Khim. 11:293-301(1985) Cited for: PROTEIN SEQUENCE.

Cross-references

Sequence databases
PIR	JN0380.
3D structure databases
ProteinModelPortal	P16344.
SMR	P16344. Positions 2-56.
ModBase	Search...
Protein family/group databases
MEROPS	I02.061.
Protocols and materials databases
StructuralBiologyKnowledgebase	Search...
Family and domain databases
Gene3D	4.10.410.10. 1 hit.
InterPro	IPR002223. Prot_inh_Kunz-m. [Graphical view]
Pfam	PF00014. Kunitz_BPTI. 1 hit. [Graphical view]
PRINTS	PR00759. BASICPTASE.
SMART	SM00131. KU. 1 hit. [Graphical view]
SUPFAM	SSF57362. Prot_inh_Kunz-m. 1 hit.
PROSITE	PS00280. BPTI_KUNITZ_1. False negative. PS50279. BPTI_KUNITZ_2. 1 hit. [Graphical view]
ProtoNet	Search...

Entry information

Entry name

ITR4_HETCR

Accession

Primary (citable) accession number: P16344

Entry history

Integrated into UniProtKB/Swiss-Prot:	August 1, 1990
Last sequence update:	August 1, 1990
Last modified:	March 6, 2013
This is version 62 of the entry and version 1 of the sequence. [Complete history]

Entry status

Reviewed (UniProtKB/Swiss-Prot)