Reviewed, UniProtKB/Swiss-Prot P20474 (PA21_BOTAS)

Names and origin

Protein names	Recommended name:     Phospholipase A2     EC=3.1.1.4 Alternative name(s):     Phosphatidylcholine 2-acylhydrolase     Myotoxin III       Short name=Myotoxin I
Organism	Bothrops asper (Terciopelo)
Taxonomic identifier	8722 [NCBI]
Taxonomic lineage	Eukaryota › Metazoa › Chordata › Craniata › Vertebrata › Euteleostomi › Lepidosauria › Squamata › Scleroglossa › Serpentes › Colubroidea › Viperidae › Crotalinae › Bothrops

Protein attributes

Sequence length	138 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	PA2 catalyzes the calcium-dependent hydrolysis of the 2-acyl groups in 3-sn-phosphoglycerides. Displays local myotoxic activity and induces a dose-dependent edema. Myotoxic activity is probably related to a molecular region different from the catalytic site, although enzymatic activity greatly enhances myotoxin action. Ref.2 Ref.3 Ref.5 Ref.6 Ref.7
Catalytic activity	Phosphatidylcholine + H2O = 1-acylglycerophosphocholine + a carboxylate.
Cofactor	Binds 1 calcium ion per subunit By similarity.
Subunit structure	Monomer. Ref.2
Subcellular location	Secreted.
Tissue specificity	Expressed by the venom gland.
Toxic dose	LD50 is 5.6 mg/kg (95ug/16-18g) by intravenous injection and 25 µg/kg (0.42ug/16-18g) by intracerebroventricular injection into mice. Ref.4
Sequence similarities	Belongs to the phospholipase A2 family. Group II subfamily.

Ontologies

Keywords
Biological process	Lipid degradation
Cellular component	Secreted
Domain	Signal
Ligand	Calcium Metal-binding
Molecular function	Hydrolase Myotoxin Toxin
PTM	Disulfide bond
Technical term	Direct protein sequencing
Gene Ontology (GO)
Biological process	lipid catabolic process Inferred from electronic annotation. Source: UniProtKB-KW pathogenesis Inferred from electronic annotation. Source: UniProtKB-KW phospholipid metabolic process Inferred from electronic annotation. Source: InterPro
Cellular component	extracellular region Inferred from electronic annotation. Source: UniProtKB-SubCell
Molecular function	calcium ion binding Inferred from electronic annotation. Source: UniProtKB-KW phospholipase A2 activity Inferred from electronic annotation. Source: EC
Complete GO annotation...

Sequence annotation (Features)

	Feature key	Position(s)	Length	Description	Graphical view	Feature identifier
Molecule processing
	Signal peptide	1 – 16	16	Ref.2
	Chain	17 – 138	122	Phospholipase A2		PRO_0000161617
Sites
	Active site	63	1	By similarity
	Active site	105	1	By similarity
	Metal binding	43	1	Calcium; via carbonyl oxygen By similarity
	Metal binding	45	1	Calcium; via carbonyl oxygen By similarity
	Metal binding	46	1	Calcium; via carbonyl oxygen By similarity
	Metal binding	64	1	Calcium By similarity
Amino acid modifications
	Disulfide bond	42 ↔ 131		By similarity
	Disulfide bond	44 ↔ 60		By similarity
	Disulfide bond	59 ↔ 111		By similarity
	Disulfide bond	65 ↔ 138		By similarity
	Disulfide bond	66 ↔ 104		By similarity
	Disulfide bond	73 ↔ 97		By similarity
	Disulfide bond	91 ↔ 102		By similarity

Sequences

	Sequence		Length	Mass (Da)
	P20474-1 [UniParc]. Last modified January 15, 2008. Version 2. Checksum: 822EAD31537AC536	FASTA	138	15,751
	10 20 30 40 50 60 MRTLWIMAVL LVGVEGSLIE FAKMILEETK RLPFPYYTTY GCYCGWGGQG QPKDATDRCC 70 80 90 100 110 120 FVHDCCYGKL SNCKPKTDRY SYSRKSGVII CGEGTPCEKQ ICECDKAAAV CFRENLRTYK 130 KRYMAYPDLL CKKPAEKC

References

[1]	"Cloning and cDNA sequence analysis of Lys(49) and Asp(49) basic phospholipase A(2) myotoxin isoforms from Bothrops asper." Lizano S., Lambeau G., Lazdunski M. Int. J. Biochem. Cell Biol. 33:127-132(2001) [PubMed: 11240369] [Abstract] Cited for: NUCLEOTIDE SEQUENCE [MRNA]. Tissue: Venom gland.
[2]	"The amino acid sequence of a myotoxic phospholipase from the venom of Bothrops asper." Kaiser I.I., Gutierrez J.M., Plummer D., Aird S.D., Odell G.V. Arch. Biochem. Biophys. 278:319-325(1990) [PubMed: 2327788] [Abstract] Cited for: PROTEIN SEQUENCE OF 17-138, FUNCTION, SUBUNIT. Tissue: Venom.
[3]	"Isolation of a myotoxin from Bothrops asper venom: partial characterization and action on skeletal muscle." Gutierrez J.M., Ownby C.L., Odell G.V. Toxicon 22:115-128(1984) [PubMed: 6426093] [Abstract] Cited for: FUNCTION.
[4]	"Pharmacological activities of a toxic phospholipase A isolated from the venom of the snake Bothrops asper." Gutierrez J.M., Lomonte B., Chaves F., Moreno E., Cerdas L. Comp. Biochem. Physiol. 84C:159-164(1986) [PubMed: 2873948] [Abstract] Cited for: LETHAL DOSE.
[5]	"Effects on cultured mammalian cells of myotoxin III, a phospholipase A2 isolated from Bothrops asper (terciopelo) venom." Butron E., Ghelestam M., Gutierrez J.M. Biochim. Biophys. Acta 1179:253-259(1993) [PubMed: 8218369] [Abstract] Cited for: FUNCTION.
[6]	"Effects of Bothrops asper (terciopelo) myotoxin III, a basic phospholipase A2, on liposomes and mouse gastrocnemius muscle." Bultron E., Gutierrez J.M., Thelestam M. Toxicon 31:217-222(1993) [PubMed: 8456450] [Abstract] Cited for: FUNCTION.
[7]	"Pharmacological modulation of edema induced by Lys-49 and Asp-49 myotoxic phospholipases A2 isolated from the venom of the snake Bothrops asper (terciopelo)." Chaves F., Leon G., Alvarado V.H., Gutierrez J.M. Toxicon 36:1861-1869(1998) [PubMed: 9839670] [Abstract] Cited for: FUNCTION.

Cross-references

Sequence databases
PIR	S09314.
3D structure databases
SMR	P20474. Positions 18-138.
ModBase	Search...
Phylogenomic databases
HOVERGEN	P20474.
Enzyme and pathway databases
BRENDA	3.1.1.4. 18616.
Family and domain databases
InterPro	IPR016090. Phospholipase_A2. IPR013090. Phospholipase_A2_AS. IPR001211. Phospholipase_A2_euk. [Graphical view]
Gene3D	G3DSA:1.20.90.10. Phospholipase_A2. 1 hit.
PANTHER	PTHR11716. Phospholipase_A2. 1 hit.
Pfam	PF00068. Phospholip_A2_1. 1 hit. [Graphical view]
PRINTS	PR00389. PHPHLIPASEA2.
SMART	SM00085. PA2c. 1 hit. [Graphical view]
PROSITE	PS00119. PA2_ASP. 1 hit. PS00118. PA2_HIS. 1 hit. [Graphical view]
ProtoNet	Search...

Entry information

Entry name

PA21_BOTAS

Accession

Primary (citable) accession number: P20474

Entry history

Integrated into UniProtKB/Swiss-Prot:	February 1, 1991
Last sequence update:	January 15, 2008
Last modified:	January 19, 2010
This is version 73 of the entry and version 2 of the sequence. [Complete history]

Entry status

Reviewed (UniProtKB/Swiss-Prot)

Annotation project

Tox-Prot (Toxin Annotation Project)