P10292 (ITR4_CUCSA) Reviewed, UniProtKB/Swiss-Prot

Names and origin

Protein names	Recommended name: Trypsin inhibitor 4 Alternative name(s): CSTI-IV Trypsin inhibitor IV
Organism	Cucumis sativus (Cucumber)
Taxonomic identifier	3659 [NCBI]
Taxonomic lineage	cellular organisms › Eukaryota › Viridiplantae › Streptophyta › Streptophytina › Embryophyta › Tracheophyta › Euphyllophyta › Spermatophyta › Magnoliophyta › eudicotyledons › core eudicotyledons › rosids › fabids › Cucurbitales › Cucurbitaceae › Benincaseae › Cucumis

Protein attributes

Sequence length	30 AA.
Sequence status	Complete.
Protein existence	Evidence at protein level

General annotation (Comments)

Function	Inhibits trypsin.
Subcellular location	Secreted.
Domain	The presence of a 'disulfide through disulfide knot' structurally defines this protein as a knottin By similarity.
Sequence similarities	Belongs to the protease inhibitor I7 (squash-type serine protease inhibitor) family. [View classification]

Ontologies

Keywords
Cellular component	Secreted
Domain	Knottin
Molecular function	Protease inhibitor Serine protease inhibitor
PTM	Disulfide bond
Technical term	Direct protein sequencing
Gene Ontology (GO)
Biological_process	negative regulation of endopeptidase activity Inferred from electronic annotation. Source: GOC
Cellular_component	extracellular region 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
	Peptide	1 – 30	30	Trypsin inhibitor 4		PRO_0000044377
Sites
	Site	5 – 6	2	Reactive bond
Amino acid modifications
	Disulfide bond	3 ↔ 20		By similarity
	Disulfide bond	10 ↔ 22		By similarity
	Disulfide bond	16 ↔ 29		By similarity

Sequences

	Sequence		Length	Mass (Da)
	P10292 [UniParc]. Last modified July 1, 1989. Version 1. Checksum: 7A4B870E7D2A088F	FASTA	30	3,429
	10 20 30 MMCPRILMKC KHDSDCLPGC VCLEHIEYCG

References

[1]

"The squash family of serine proteinase inhibitors. Amino acid sequences and association equilibrium constants of inhibitors from squash, summer squash, zucchini, and cucumber seeds." Wieczorek M., Otlewski J., Cook J., Parks K., Leluk J., Wilimowska-Pelc A., Polanowski A., Wilusz T., Laskowski M. Jr. Biochem. Biophys. Res. Commun. 126:646-652(1985) [PubMed] [Europe PMC] [Abstract] Cited for: PROTEIN SEQUENCE. Tissue: Seed.

Cross-references

3D structure databases
ProteinModelPortal	P10292.
SMR	P10292. Positions 2-30.
ModBase	Search...
Protein family/group databases
MEROPS	I07.015.
Protocols and materials databases
StructuralBiologyKnowledgebase	Search...
Family and domain databases
InterPro	IPR000737. Prot_inh_squash. IPR011052. Proteinase_amylase_inhib_dom. [Graphical view]
Pfam	PF00299. Squash. 1 hit. [Graphical view]
PRINTS	PR00293. SQUASHINHBTR.
SMART	SM00286. PTI. 1 hit. [Graphical view]
SUPFAM	SSF57027. Prot_amyl_inhib. 1 hit.
PROSITE	PS00286. SQUASH_INHIBITOR. 1 hit. [Graphical view]
ProtoNet	Search...

Entry information

Entry name

ITR4_CUCSA

Accession

Primary (citable) accession number: P10292

Entry history

Integrated into UniProtKB/Swiss-Prot:	July 1, 1989
Last sequence update:	July 1, 1989
Last modified:	April 3, 2013
This is version 69 of the entry and version 1 of the sequence. [Complete history]

Entry status

Reviewed (UniProtKB/Swiss-Prot)

Annotation program

Plant Protein Annotation Program