O46162 (SGP1_SCHGR) Reviewed, UniProtKB/Swiss-Prot

Names and origin

Protein names	Recommended name: Serine protease inhibitor I/II Cleaved into the following 2 chains: Protease inhibitor SGPI-1 Alternative name(s): Schistocerca gregaria trypsin inhibitor Short name=SGTI Protease inhibitor SGPI-2 Alternative name(s): Schistocerca gregaria chymotrypsin inhibitor Short name=SGCI
Organism	Schistocerca gregaria (Desert locust)
Taxonomic identifier	7010 [NCBI]
Taxonomic lineage	cellular organisms › Eukaryota › Opisthokonta › Metazoa › Eumetazoa › Bilateria › Protostomia › Ecdysozoa › Panarthropoda › Arthropoda › Mandibulata › Pancrustacea › Hexapoda › Insecta › Dicondylia › Pterygota › Neoptera › Orthopteroidea › Orthoptera › Caelifera › Acridomorpha › Acridoidea › Acrididae › Cyrtacanthacridinae › Schistocerca

Protein attributes

Sequence length	92 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	In vitro, SGPI-1/SGCI is active against alpha-chymotrypsin and trypsin while SGPI-2/SGTI is active against alpha-chymotrypsin and pancreatic elastase. Ref.2
Subcellular location	Secreted.
Tissue specificity	Expressed in hemolymph, ovaries, testes and fat body of adults but are absent in the gut. Also present in larval hemolymph and fat body. Ref.2
Sequence similarities	Belongs to the protease inhibitor I19 family. [View classification] Contains 2 pacifastin domains.

Ontologies

Keywords
Cellular component	Secreted
Domain	Repeat Signal
Molecular function	Protease inhibitor Serine protease inhibitor
PTM	Cleavage on pair of basic residues 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

Signal peptide

1 – 19

19

Ref.2

Peptide

20 – 54

35

Protease inhibitor SGPI-1 Ref.2

PRO_0000026710

Peptide

57 – 91

35

Protease inhibitor SGPI-2

PRO_0000026711

Regions

Domain

20 – 54

35

Pacifastin 1

Domain

57 – 92

36

Pacifastin 2

Sites

Site

48 – 49

2

Reactive bond

Site

86 – 87

2

Reactive bond

Amino acid modifications

Disulfide bond

23 ↔ 38

Disulfide bond

33 ↔ 51

Disulfide bond

36 ↔ 46

Disulfide bond

60 ↔ 75

Disulfide bond

70 ↔ 89

Disulfide bond

73 ↔ 84

Secondary structure

1

.

.

.

.

.

.

.

.

.

.

.

.

.

.

.

.

92

Helix Strand Turn

Details...

Beta strand

28 – 31

4

Beta strand

34 – 38

5

Beta strand

44 – 47

4

Turn

62 – 64

3

Beta strand

65 – 68

4

Beta strand

71 – 75

5

Beta strand

77 – 80

4

Beta strand

82 – 85

4

Sequences

	Sequence		Length	Mass (Da)
	O46162 [UniParc]. Last modified June 1, 1998. Version 1. Checksum: 9E5A228C767C657C	FASTA	92	9,842
	10 20 30 40 50 60 MKLALALCAA FLLVVLVQAE QECTPGQTKK QDCNTCNCTP TGVWACTRKG CPPHKREVTC 70 80 90 EPGTTFKDKC NTCRCGSDGK SAACTLKACP QK

References

[1]	"Cloning of two cDNAs encoding three small serine protease inhibiting peptides from the desert locust Schistocerca gregaria and analysis of tissue-dependent and stage-dependent expression." Vanden Broeck J., Chiou S.-J., Schoofs L., Hamdaoui A., Vandenbussche F., Simonet G., Wataleb S., De Loof A. Eur. J. Biochem. 254:90-95(1998) [PubMed] [Europe PMC] [Abstract] Cited for: NUCLEOTIDE SEQUENCE [MRNA]. Tissue: Ovary.
[2]	"Purification and characterization of a group of five novel peptide serine protease inhibitors from ovaries of the desert locust, Schistocerca gregaria." Hamdaoui A., Wataleb S., Devreese B., Chiou S.-J., Vanden Broeck J., Van Beeumen J., De Loof A., Schoofs L. FEBS Lett. 422:74-78(1998) [PubMed] [Europe PMC] [Abstract] Cited for: PROTEIN SEQUENCE OF 20-54 AND 57-91, FUNCTION, TISSUE SPECIFICITY. Tissue: Ovary.
[3]	"Structural and functional properties of a novel serine protease inhibiting peptide family in arthropods." Simonet G., Claeys I., Vanden Broeck J. Comp. Biochem. Physiol. 132B:247-255(2002) [PubMed] [Europe PMC] [Abstract] Cited for: STRUCTURE BY NMR OF 20-54 AND 57-91.
+	Additional computationally mapped references.

Cross-references

Sequence databases

EMBL
GenBank
DDBJ

Y09605 mRNA. Translation: CAA70818.1.

3D structure databases

PDBe
RCSB PDB
PDBj

Entry	Method	Resolution (Å)	Chain	Positions	PDBsum
1KGM	NMR	-	A	57-91	[»]
1KIO	NMR	-	A	57-91	[»]
1KJ0	NMR	-	A	20-54	[»]
2F91	X-ray	1.20	B	20-54	[»]
2XTT	X-ray	0.93	A	20-54	[»]
3TVJ	X-ray	1.28	I	57-85	[»]

ProteinModelPortal

O46162.

SMR

O46162. Positions 20-54, 57-91.

ModBase

Search...

Protein family/group databases

MEROPS

I19.001.

Protocols and materials databases

StructuralBiologyKnowledgebase

Search...

Family and domain databases

InterPro

IPR020862. Pacifastin_art.
IPR008037. Prot_inh_PMP.
IPR016307. Prtase-inh_pacifastin.
[Graphical view]

Pfam

PF05375. Pacifastin_I. 2 hits.
[Graphical view]

PIRSF

PIRSF001625. Prot_inhib_pacifastin. 1 hit.

SUPFAM

SSF57283. PMP_SGCI. 2 hits.

PROSITE

PS51446. PACIFASTIN. 2 hits.
[Graphical view]

ProtoNet

Search...

Other

EvolutionaryTrace

O46162.

Entry information

Entry name

SGP1_SCHGR

Accession

Primary (citable) accession number: O46162

Entry history

Integrated into UniProtKB/Swiss-Prot:	August 16, 2004
Last sequence update:	June 1, 1998
Last modified:	April 3, 2013
This is version 62 of the entry and version 1 of the sequence. [Complete history]

Entry status

Reviewed (UniProtKB/Swiss-Prot)