P10295 (ITR2_MOMCH) Reviewed, UniProtKB/Swiss-Prot

Names and origin

Protein names	Recommended name: Trypsin inhibitor 2 Alternative name(s): MCTI-A MCTI-II Trypsin inhibitor II
Organism	Momordica charantia (Bitter gourd) (Balsam pear)
Taxonomic identifier	3673 [NCBI]
Taxonomic lineage	cellular organisms › Eukaryota › Viridiplantae › Streptophyta › Streptophytina › Embryophyta › Tracheophyta › Euphyllophyta › Spermatophyta › Magnoliophyta › eudicotyledons › core eudicotyledons › rosids › fabids › Cucurbitales › Cucurbitaceae › Momordiceae › Momordica

Protein attributes

Sequence length	28 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.
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	3D-structure 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 – 28

28

Trypsin inhibitor 2

PRO_0000044387

Sites

Site

5 – 6

2

Reactive bond

Amino acid modifications

Disulfide bond

3 ↔ 20

Ref.1

Disulfide bond

10 ↔ 22

Ref.1

Disulfide bond

16 ↔ 27

Ref.1

Secondary structure

1

.

.

.

28

Helix Strand Turn

Details...

Helix

13 – 15

3

Sequences

	Sequence		Length	Mass (Da)
	P10295 [UniParc]. Last modified July 1, 1989. Version 1. Checksum: 67E263D36974FEDF	FASTA	28	3,230
	10 20 RICPRIWMEC KRDSDCMAQC ICVDGHCG

References

[1]	"Amino acid sequences and disulfide bridges of serine proteinase inhibitors from bitter gourd (Momordica charantia LINN.) seeds." Hara S., Makino J., Ikenaka T. J. Biochem. 105:88-92(1989) [PubMed] [Europe PMC] [Abstract] Cited for: PROTEIN SEQUENCE, DISULFIDE BONDS. Tissue: Seed.
[2]	"Refined 1.6-A resolution crystal structure of the complex formed between porcine beta-trypsin and MCTI-A, a trypsin inhibitor of the squash family. Detailed comparison with bovine beta-trypsin and its complex." Huang Q., Liu S., Tang Y. J. Mol. Biol. 229:1022-1036(1993) [PubMed] [Europe PMC] [Abstract] Cited for: X-RAY CRYSTALLOGRAPHY (1.6 ANGSTROMS).
[3]	"Amino acid sequencing of a trypsin inhibitor by refined 1.6 A X-ray crystal structure of its complex with porcine beta-trypsin." Huang Q., Liu S., Tang Y., Zeng F., Qian R. FEBS Lett. 297:143-146(1992) [PubMed] [Europe PMC] [Abstract] Cited for: X-RAY CRYSTALLOGRAPHY (1.6 ANGSTROMS).
+	Additional computationally mapped references.

Cross-references

Sequence databases

PIR

JC2507.
JX0058.

3D structure databases

PDBe
RCSB PDB
PDBj

Entry	Method	Resolution (Å)	Chain	Positions	PDBsum
1F2S	X-ray	1.79	I	1-28	[»]

ModBase

Search...

Protein-protein interaction databases

MINT

MINT-108133.

Protein family/group databases

MEROPS

I07.008.

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...

Other

EvolutionaryTrace

P10295.

Entry information

Entry name

ITR2_MOMCH

Accession

Primary (citable) accession number: P10295

Entry history

Integrated into UniProtKB/Swiss-Prot:	July 1, 1989
Last sequence update:	July 1, 1989
Last modified:	April 3, 2013
This is version 74 of the entry and version 1 of the sequence. [Complete history]

Entry status

Reviewed (UniProtKB/Swiss-Prot)

Annotation program

Plant Protein Annotation Program