Reviewed, UniProtKB/Swiss-Prot P01070 (ITRA_SOYBN)

Names and origin

Protein names

Recommended name:
    Trypsin inhibitor A
Alternative name(s):
    Kunitz-type trypsin inhibitor A

Gene names

Name:

KTI3

Organism

Glycine max (Soybean)

Taxonomic identifier

3847 [NCBI]

Taxonomic lineage

Eukaryota › Viridiplantae › Streptophyta › Embryophyta › Tracheophyta › Spermatophyta › Magnoliophyta › eudicotyledons › core eudicotyledons › rosids › eurosids I › Fabales › Fabaceae › Papilionoideae › Phaseoleae › Glycine

Protein attributes

Sequence length	216 AA.
Sequence status	Complete.
Sequence processing	The displayed sequence is further processed into a mature form.
Protein existence	Evidence at protein level.

General annotation (Comments)

Function	Inhibition of trypsin.
Miscellaneous	The sequence of variant A is shown. Electrophoresis identifies three genetically distinct variants, A, B, and C, that are inherited as codominant alleles.
Sequence similarities	Belongs to the protease inhibitor I3 (leguminous Kunitz-type inhibitor) family. [View classification]
Caution	Ref.4 sequence was originally thought to be rat caltrin. A number of peptide fragments were derived from a trypsin digest of caltrin and soybean trypsin inhibitor was used to stop the digestion. It appears that some of the inhibitor was also digested and sequenced.

Ontologies

Keywords
Domain	Signal
Molecular function	Protease inhibitor Serine protease inhibitor
PTM	Disulfide bond
Technical term	3D-structure Direct protein sequencing
Gene Ontology (GO)
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

Signal peptide

1 – 24

24

Ref.2 Ref.3 Ref.4

Chain

25 – 205

181

Trypsin inhibitor A

PRO_0000016889

Propeptide

206 – 216

11

PRO_0000016890

Sites

Site

87 – 88

2

Reactive bond for trypsin

Amino acid modifications

Disulfide bond

63 ↔ 110

Ref.5

Disulfide bond

160 ↔ 169

Ref.5

Natural variations

Natural variant

79

1

G → E in variant C.

Experimental info

Sequence conflict

25

1

D → S AA sequence Ref.4

Secondary structure

1

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216

Helix Strand Turn

Details...

Turn

30 – 32

3

Beta strand

39 – 46

8

Beta strand

53 – 56

4

Beta strand

66 – 69

4

Beta strand

80 – 83

4

Beta strand

85 – 87

3

Beta strand

97 – 101

5

Helix

108 – 110

3

Beta strand

118 – 120

3

Beta strand

126 – 130

5

Beta strand

140 – 146

7

Beta strand

155 – 161

7

Beta strand

170 – 176

7

Beta strand

178 – 180

3

Beta strand

183 – 188

6

Beta strand

195 – 199

5

Sequences

	Sequence		Length	Mass (Da)
	P01070-1 [UniParc]. Last modified May 1, 1992. Version 2. Checksum: 1251FE0DE46CCA96	FASTA	216	24,005
	10 20 30 40 50 60 MKSTIFFLFL FCAFTTSYLP SAIADFVLDN EGNPLENGGT YYILSDITAF GGIRAAPTGN 70 80 90 100 110 120 ERCPLTVVQS RNELDKGIGT IISSPYRIRF IAEGHPLSLK FDSFAVIMLC VGIPTEWSVV 130 140 150 160 170 180 EDLPEGPAVK IGENKDAMDG WFRLERVSDD EFNNYKLVFC PQQAEDDKCG DIGISIDHDD 190 200 210 GTRRLVVSKN KPLVVQFQKL DKESLAKKNH GLSRSE

References

[1]	"A frameshift mutation prevents Kunitz trypsin inhibitor mRNA accumulation in soybean embryos." Jofuku K.D., Schipper R.D., Goldberg R.B. Plant Cell 1:427-435(1989) [PubMed: 2562563] [Abstract] Cited for: NUCLEOTIDE SEQUENCE [MRNA].
[2]	"Studies on soybean trypsin inhibitors. 3. Amino-acid sequences of the carboxyl-terminal region and the complete amino-acid sequence of soybean trypsin inhibitor (Kunitz)." Koide T., Ikenaka T. Eur. J. Biochem. 32:417-431(1973) [PubMed: 4734969] [Abstract] Cited for: PROTEIN SEQUENCE OF 25-205 (VARIANT A).
[3]	"Comparative study on amino acid sequences of Kunitz-type soybean trypsin inhibitors, Tia, Tib, and Tic." Kim S.-H., Hara S., Hase S., Ikenaka T., Toda H., Kitamura K., Kaizuma N. J. Biochem. 98:435-448(1985) [PubMed: 3905784] [Abstract] Cited for: PROTEIN SEQUENCE OF 25-205 (VARIANT C), SEQUENCE REVISION (VARIANT A). Strain: cv. Raiden.
[4]	"Isolation and characterization of a 54-kilodalton precursor of caltrin, the calcium transport inhibitor protein from seminal vesicles of the rat." Coronel C.E., Novella M.L., Winnica D.E., Lardy H.A. Biol. Reprod. 48:1326-1333(1993) [PubMed: 8318586] [Abstract] Cited for: PROTEIN SEQUENCE OF 25-56.
[5]	"The amino acid sequences around the disulfide bonds of soybean trypsin inhibitor." Brown J.R., Lerman N., Bohak Z. Biochem. Biophys. Res. Commun. 23:561-565(1966) [PubMed: 6006643] [Abstract] Cited for: DISULFIDE BONDS.
[6]	"The reactive site of trypsin inhibitors." Ozawa K., Laskowski M. Jr. J. Biol. Chem. 241:3955-3961(1966) [PubMed: 5950769] [Abstract] Cited for: INHIBITORY SITE.
[7]	"Crystal structure of the complex of porcine trypsin with soybean trypsin inhibitor (Kunitz) at 2.6-A resolution." Sweet R.M., Wright H.T., Janin J., Chothia C.H., Blow D.M. Biochemistry 13:4212-4228(1974) [PubMed: 4472048] [Abstract] Cited for: X-RAY CRYSTALLOGRAPHY (2.6 ANGSTROMS).
[8]	"Structure of the Kunitz-type soybean trypsin inhibitor (STI): implication for the interactions between members of the STI family and tissue-plasminogen activator." de Meester P., Brick P., Lloyd L.F., Blow D.M., Onesti S. Acta Crystallogr. D 54:589-597(1998) [PubMed: 9761854] [Abstract] Cited for: X-RAY CRYSTALLOGRAPHY (2.5 ANGSTROMS).
[9]	"Kunitz-type soybean trypsin inhibitor revisited: refined structure of its complex with porcine trypsin reveals an insight into the interaction between a homologous inhibitor from Erythrina caffra and tissue-type plasminogen activator." Song H.K., Suh S.W. J. Mol. Biol. 275:347-363(1998) [PubMed: 9466914] [Abstract] Cited for: X-RAY CRYSTALLOGRAPHY (2.3 ANGSTROMS).

Cross-references

Sequence databases

EMBLGenBankDDBJ

S45092 mRNA. Translation: AAB23464.1.

PIR

JQ0968.

UniGene

Gma.29257

3D structure databases

PDBPDBe

Entry	Method	Resolution (Å)	Chain	Positions	PDBsum
1AVU	X-ray	2.30	A	25-205	[»]
1AVW	X-ray	1.75	B	25-201	[»]
1AVX	X-ray	1.90	B	25-201	[»]
1BA7	X-ray	2.50	A/B	25-205	[»]

ModBase

Search...

Protein-protein interaction databases

DIP

DIP:6101N.

Protein family/group databases

MEROPS

I03.001.

Family and domain databases

InterPro

IPR002160. Prot_inh_Kunz-lg.
[Graphical view]

Pfam

PF00197. Kunitz_legume. 1 hit.
[Graphical view]

PRINTS

PR00291. KUNITZINHBTR.

ProDom

PD000891. Prot_inh_Kunz-lg. 1 hit.
[Graphical view] [Entries sharing at least one domain]

SMART

SM00452. STI. 1 hit.
[Graphical view]

PROSITE

PS00283. SOYBEAN_KUNITZ. 1 hit.
[Graphical view]

ProtoNet

Search...

Entry information

Entry name

ITRA_SOYBN

Accession

Primary (citable) accession number: P01070
Secondary accession number(s): Q9QV66

Entry history

Integrated into UniProtKB/Swiss-Prot:	July 21, 1986
Last sequence update:	May 1, 1992
Last modified:	June 16, 2009
This is version 84 of the entry and version 2 of the sequence. [Complete history]

Entry status

Reviewed (UniProtKB/Swiss-Prot)

Annotation project

PPAP (Plant Proteome Annotation Project)