P01074 (ITR1_CUCMA) Reviewed, UniProtKB/Swiss-Prot

Names and origin

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

Protein attributes

Sequence length	29 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)
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 [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

PDBe
RCSB PDB
PDBj

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	[»]

ProteinModelPortal

P01074.

SMR

P01074. Positions 2-29.

ModBase

Search...

Protein family/group databases

MEROPS

I07.005.

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

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:	May 31, 2011
This is version 76 of the entry and version 1 of the sequence. [Complete history]

Entry status

Reviewed (UniProtKB/Swiss-Prot)

Annotation program

Plant Protein Annotation Program