Reviewed, UniProtKB/Swiss-Prot P0C577 (VSPG_BITGA)

Names and origin

Protein names	Recommended name:     Thrombin-like enzyme gabonase     EC=3.4.21.55 Alternative name(s):     Venombin-AB
Organism	Bitis gabonica (Gaboon adder) (Gaboon viper)
Taxonomic identifier	8694 [NCBI]
Taxonomic lineage	Eukaryota › Metazoa › Chordata › Craniata › Vertebrata › Euteleostomi › Lepidosauria › Squamata › Scleroglossa › Serpentes › Colubroidea › Viperidae › Viperinae › Bitis

Protein attributes

Sequence length	19 AA.
Sequence status	Fragment.
Sequence processing	The displayed sequence is not processed.
Protein existence	Evidence at protein level.

General annotation (Comments)

Function	Thrombin-like snake venom serine protease. Releases both fibrinopeptides A and B from fibrinogen to form fibrin clots. Also activates factor XIII. The activity of the enzyme is stabilized by calcium ion.
Catalytic activity	Preferential cleavage: Arg-|-Xaa bonds in fibrinogen to form fibrin and release fibrinopeptides A and B.
Enzyme regulation	Inactivated by phenylmethanesulfonyl fluoride (PMF). Not inactivated by heparin, hirudin and antithrombin III.
Subcellular location	Secreted.
Tissue specificity	Expressed by the venom gland.
Post-translational modification	Glycosylated. Contains five disulfide bonds Probable.
Sequence similarities	Belongs to the peptidase S1 family. Snake venom subfamily. Contains 1 peptidase S1 domain.
biophysicochemical properties	Kinetic parameters: KM=0.12 mM for Tosyl-L-arginine methyl ester (TAME) KM=0.13 mM for Tosyl-Gly-Pro-Arg 4-nitroanilide KM=0.82 mM for H-D-Pro-hexahydrotyrosyl-Arg 4-nitroanilide KM=0.88 mM for H-D-Hexahydrotyrosyl-Ala-Arg 4-nitroanilide KM=2.72 mM for Tosyl-Gly-Pro-Lys 4-nitroanilide KM=3.4 mM for H-D-Phenylglycine-Phe-Arg 4-nitroanilide Temperature dependence: Optimum temperature is 30 degrees Celsius with tosyl-Arg-methyl ester (TAME) as substrate and 37 degrees Celsius with natural substrates.

Ontologies

Keywords
Biological process	Blood coagulation
Cellular component	Secreted
Ligand	Calcium
Molecular function	Hydrolase Protease Serine protease Toxin
PTM	Disulfide bond Glycoprotein
Technical term	Direct protein sequencing
Gene Ontology (GO)
Biological process	blood coagulation Inferred from electronic annotation. Source: UniProtKB-KW pathogenesis Inferred from electronic annotation. Source: UniProtKB-KW
Cellular component	extracellular region Inferred from electronic annotation. Source: UniProtKB-SubCell
Molecular function	calcium ion binding Inferred from electronic annotation. Source: UniProtKB-KW serine-type peptidase 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 – ›19	›19	Thrombin-like enzyme gabonase		PRO_0000295177
Regions
	Domain	1 – ›19	›19	Peptidase S1
Experimental info
	Non-terminal residue	19	1

Sequences

	Sequence		Length	Mass (Da)
	P0C577-1 [UniParc]. Last modified July 10, 2007. Version 1. Checksum: 4B7BA6C802F4E553	FASTA	19	2,017
	10 VVGGAECKID GHRCLALLY

References

[1]	"Thrombin-like enzyme from the venom of Bitis gabonica. Purification, properties, and coagulant actions." Pirkle H., Theodor I., Miyada D., Simmons G. J. Biol. Chem. 261:8830-8835(1986) [PubMed: 3522580] [Abstract] Cited for: PROTEIN SEQUENCE. Tissue: Venom.

Cross-references

3D structure databases
ModBase	Search...
Enzyme and pathway databases
BRENDA	3.4.21.55. 18552.
Family and domain databases
InterPro	IPR018114. Peptidase_S1/S6_AS. [Graphical view]
PROSITE	PS50240. TRYPSIN_DOM. Partial match. PS00134. TRYPSIN_HIS. Partial match. PS00135. TRYPSIN_SER. Partial match. [Graphical view]
ProtoNet	Search...

Entry information

Entry name

VSPG_BITGA

Accession

Primary (citable) accession number: P0C577

Entry history

Integrated into UniProtKB/Swiss-Prot:	July 10, 2007
Last sequence update:	July 10, 2007
Last modified:	June 16, 2009
This is version 10 of the entry and version 1 of the sequence. [Complete history]

Entry status

Reviewed (UniProtKB/Swiss-Prot)

Annotation project

Tox-Prot (Toxin Annotation Project)