Reviewed, UniProtKB/Swiss-Prot P01074 (ITR1_CUCMA)

Names and origin

Protein names	Recommended name:     Trypsin inhibitor 1 Alternative name(s):     Trypsin inhibitor I     CMTI-I     ITD-I
Organism	Cucurbita maxima (Pumpkin) (Winter squash)
Taxonomic identifier	3661 [NCBI]
Taxonomic lineage	Eukaryota › Viridiplantae › Streptophyta › Embryophyta › Tracheophyta › Spermatophyta › Magnoliophyta › eudicotyledons › core eudicotyledons › rosids › eurosids I › Cucurbitales › Cucurbitaceae › Cucurbita

Protein attributes

Sequence length	29 AA.
Sequence status	Complete.
Sequence processing	The displayed sequence is not processed.
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)
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 – 29

29

Trypsin inhibitor 1

PRO_0000044376

Sites

Site

5 – 6

2

Reactive bond

Amino acid modifications

Disulfide bond

3 ↔ 20

Ref.2

Disulfide bond

10 ↔ 22

Ref.2

Disulfide bond

16 ↔ 28

Ref.2

Secondary structure

1

.

.

.

.

.

29

Helix Strand Turn

Details...

Helix

13 – 15

3

Beta strand

26 – 28

3

Sequences

	Sequence		Length	Mass (Da)
	P01074-1 [UniParc]. Last modified July 21, 1986. Version 1. Checksum: CD509120BA52C01F	FASTA	29	3,275
	10 20 RVCPRILMEC KKDSDCLAEC VCLEHGYCG

References

[1]	"Amino-acid sequence of two trypsin isoinhibitors, ITD I and ITD III from squash seeds (Cucurbita maxima)." Wilusz T., Wieczorek M., Polanowski A., Denton A., Cook J., Laskowski M. Jr. Hoppe-Seyler's Z. Physiol. Chem. 364:93-95(1983) [PubMed: 6840699] [Abstract] Cited for: PROTEIN SEQUENCE. Tissue: Seed.
[2]	"The refined 2.0 A X-ray crystal structure of the complex formed between bovine beta-trypsin and CMTI-I, a trypsin inhibitor from squash seeds (Cucurbita maxima). Topological similarity of the squash seed inhibitors with the carboxypeptidase A inhibitor from potatoes." Bode W., Greyling H.J., Huber R., Otlewski J., Wilusz T. FEBS Lett. 242:285-292(1989) [PubMed: 2914611] [Abstract] Cited for: X-RAY CRYSTALLOGRAPHY (2.0 ANGSTROMS).
[3]	"Determination of the complete three-dimensional structure of the trypsin inhibitor from squash seeds in aqueous solution by nuclear magnetic resonance and a combination of distance geometry and dynamical simulated annealing." Holak T.A., Gondol D., Otlewski J., Wilusz T. J. Mol. Biol. 210:635-648(1989) [PubMed: 2614837] [Abstract] Cited for: STRUCTURE BY NMR.
[4]	"Conservative mutation Met8 --> Leu affects the folding process and structural stability of squash trypsin inhibitor CMTI-I." Zhukov I., Jaroszewski L., Bierzynski A. Protein Sci. 9:273-279(2000) [PubMed: 10716179] [Abstract] Cited for: STRUCTURE BY NMR.
+	Additional computationally mapped references.

Cross-references

Sequence databases

PIR

TIPU. A01313.

3D structure databases

PDBPDBe

Entry	Method	Resolution (Å)	Chain	Positions	PDBsum
1CTI	NMR	-	A	1-29	[»]
1LU0	X-ray	1.03	A/B	1-29	[»]
1PPE	X-ray	2.00	I	1-29	[»]
2CTI	NMR	-	A	1-29	[»]
2STA	X-ray	1.80	I	1-29	[»]
2V1V	NMR	-	A	1-29	[»]
3CTI	NMR	-	A	1-29	[»]

ModBase

Search...

Protein family/group databases

MEROPS

I07.005.

Family and domain databases

InterPro

IPR000737. Prot_inh_squash.
[Graphical view]

Pfam

PF00299. Squash. 1 hit.
[Graphical view]

PRINTS

PR00293. SQUASHINHBTR.

ProDom

PD003401. Prot_inh_squash. 1 hit.
[Graphical view] [Entries sharing at least one domain]

SMART

SM00286. PTI. 1 hit.
[Graphical view]

PROSITE

PS00286. SQUASH_INHIBITOR. 1 hit.
[Graphical view]

ProtoNet

Search...

Other Resources

PMAP-CutDB

P01074.

Entry information

Entry name

ITR1_CUCMA

Accession

Primary (citable) accession number: P01074

Entry history

Integrated into UniProtKB/Swiss-Prot:	July 21, 1986
Last sequence update:	July 21, 1986
Last modified:	June 16, 2009
This is version 69 of the entry and version 1 of the sequence. [Complete history]

Entry status

Reviewed (UniProtKB/Swiss-Prot)

Annotation project

PPAP (Plant Proteome Annotation Project)