P16589 (ITRP_HALRO) Reviewed, UniProtKB/Swiss-Prot

Names and origin

Protein names	Recommended name: Trypsin inhibitor Alternative name(s): ATI
Organism	Halocynthia roretzi (Sea squirt)
Taxonomic identifier	7729 [NCBI]
Taxonomic lineage	cellular organisms › Eukaryota › Opisthokonta › Metazoa › Eumetazoa › Bilateria › Deuterostomia › Chordata › Tunicata › Ascidiacea › Stolidobranchia › Pyuridae › Halocynthia

Protein attributes

Sequence length	55 AA.
Sequence status	Complete.
Protein existence	Evidence at protein level

General annotation (Comments)

Function	Potent inhibitor of trypsin.
Subcellular location	Secreted.
Sequence similarities	Contains 1 Kazal-like domain.

Ontologies

Keywords
Cellular component	Secreted
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

Chain

1 – 55

55

Trypsin inhibitor

PRO_0000073202

Regions

Domain

1 – 55

55

Kazal-like

Sites

Site

16 – 17

2

Reactive bond

Amino acid modifications

Disulfide bond

5 ↔ 40

Ref.2

Disulfide bond

12 ↔ 41

Ref.2

Disulfide bond

14 ↔ 37

Ref.2

Disulfide bond

23 ↔ 54

Ref.2

Secondary structure

1

.

.

.

.

.

.

.

.

.

55

Helix Strand Turn

Details...

Beta strand

8 – 10

3

Beta strand

22 – 25

4

Beta strand

31 – 34

4

Helix

36 – 42

7

Sequences

	Sequence		Length	Mass (Da)
	P16589 [UniParc]. Last modified August 1, 1990. Version 1. Checksum: 4121548DB33207C2	FASTA	55	6,078
	10 20 30 40 50 AHMDCTEFNP LCRCNKMLGD LICAVIGDAK EEHRNMCALC CEHPGGFEYS NGPCE

References

[1]	"Primary structure of ascidian trypsin inhibitors in the hemolymph of a solitary ascidian, Halocynthia roretzi." Kumazaki T., Hoshiba N., Yokosawa H., Ishii S. J. Biochem. 107:409-413(1990) [PubMed] [Europe PMC] [Abstract] Cited for: PROTEIN SEQUENCE. Tissue: Hemolymph.
[2]	"Disulfide bridge structure of ascidian trypsin inhibitor I: similarity to Kazal-type inhibitors." Kumazaki T., Ishii S. J. Biochem. 107:414-419(1990) [PubMed] [Europe PMC] [Abstract] Cited for: DISULFIDE BONDS.
[3]	"Solution structure of ascidian trypsin inhibitor determined by nuclear magnetic resonance spectroscopy." Hemmi H., Yoshida T., Kumazaki T., Nemoto N., Hasegawa J., Nishioka F., Kyogoku Y., Yokosawa H., Kobayashi Y. Biochemistry 41:10657-10664(2002) [PubMed] [Europe PMC] [Abstract] Cited for: STRUCTURE BY NMR.

Cross-references

3D structure databases

PDBe
RCSB PDB
PDBj

Entry	Method	Resolution (Å)	Chain	Positions	PDBsum
1IW4	NMR	-	A	1-55	[»]

ProteinModelPortal

P16589.

SMR

P16589. Positions 1-55.

ModBase

Search...

Protein family/group databases

MEROPS

I05.001.

Protocols and materials databases

StructuralBiologyKnowledgebase

Search...

Family and domain databases

InterPro

IPR002350. Kazal_dom.
[Graphical view]

PROSITE

PS51465. KAZAL_2. 1 hit.
[Graphical view]

ProtoNet

Search...

Other

EvolutionaryTrace

P16589.

Entry information

Entry name

ITRP_HALRO

Accession

Primary (citable) accession number: P16589

Entry history

Integrated into UniProtKB/Swiss-Prot:	August 1, 1990
Last sequence update:	August 1, 1990
Last modified:	May 1, 2013
This is version 58 of the entry and version 1 of the sequence. [Complete history]

Entry status

Reviewed (UniProtKB/Swiss-Prot)

Annotation program

Chordata Protein Annotation Program