Reviewed, UniProtKB/Swiss-Prot Q3C2C2 (PA21_ACAPL)

Names and origin

Protein names	Recommended name:     Phospholipase A2 AP-PLA2-I     EC=3.1.1.4 Alternative name(s):     Phosphatidylcholine 2-acylhydrolase 2
Organism	Acanthaster planci (Crown-of-thorns starfish)
Taxonomic identifier	133434 [NCBI]
Taxonomic lineage	Eukaryota › Metazoa › Echinodermata › Eleutherozoa › Asterozoa › Asteroidea › Valvatacea › Valvatida › Acanthasteridae › Acanthaster

Protein attributes

Sequence length	159 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. Has hemorrhagic and capillary permeability-increasing activities and hence is considered to be deeply involved in the local inflammation. Shows hemolytic activity only in the presence of phosphatidylcholine (PC).
Catalytic activity	Phosphatidylcholine + H(2)O = 1-acylglycerophosphocholine + a carboxylate.
Cofactor	Binds 1 calcium ion per subunit By similarity.
Subunit structure	Homodimer.
Subcellular location	Secreted.
Tissue specificity	Expressed by the venom gland.
Sequence similarities	Belongs to the phospholipase A2 family. Group I subfamily.

Ontologies

Keywords
Biological process	Cytolysis Hemolysis Lipid degradation
Cellular component	Secreted
Domain	Signal
Ligand	Calcium Metal-binding
Molecular function	Hydrolase Toxin
Technical term	Direct protein sequencing
Gene Ontology (GO)
Biological process	cytolysis Inferred from electronic annotation. Source: UniProtKB-KW hemolysis by symbiont of host red blood cells Inferred from electronic annotation. Source: UniProtKB-KW lipid catabolic process Inferred from electronic annotation. Source: InterPro 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-KW
Molecular function	calcium ion binding Inferred from electronic annotation. Source: InterPro phospholipase A2 activity Inferred from electronic annotation. Source: InterPro
Complete GO annotation...

Sequence annotation (Features)

	Feature key	Position(s)	Length	Description	Graphical view	Feature identifier
Molecule processing
	Signal peptide	1 – 19	19	Potential
	Propeptide	20 – 23	4			PRO_0000272033
	Chain	24 – 159	136	Phospholipase A2 AP-PLA2-I		PRO_0000272034
Sites
	Active site	72	1	By similarity
	Active site	133	1	By similarity
	Metal binding	52	1	Calcium; via carbonyl oxygen By similarity
	Metal binding	54	1	Calcium; via carbonyl oxygen By similarity
	Metal binding	56	1	Calcium; via carbonyl oxygen By similarity
	Metal binding	73	1	Calcium By similarity
Amino acid modifications
	Disulfide bond	51 ↔ 159		By similarity
	Disulfide bond	53 ↔ 69		By similarity
	Disulfide bond	68 ↔ 139		By similarity
	Disulfide bond	75 ↔ 132		By similarity
	Disulfide bond	85 ↔ 125		By similarity
	Disulfide bond	110 ↔ 130		By similarity

Sequences

	Sequence		Length	Mass (Da)
	Q3C2C2-1 [UniParc]. Last modified November 22, 2005. Version 1. Checksum: A4F4DC8F7B0D6266	FASTA	159	17,830
	10 20 30 40 50 60 MNFLVVIVTT VSLAGAASAG EIQNLYQFGK MVMCLGNLNV LEGLEYNGYG CYCGRGGKGT 70 80 90 100 110 120 PLDDTDRCCK QHDECYERAT DEMGCWSIET YATTYDYTKS KVSGKCTIKC KLESDYSRFT 130 140 150 IRKKCKAFIC ECDRIGAQCF ADKRSTFNRS LISYTKDKC

References

[1]	"Molecular cloning of two toxic phospholipases A2 from the crown-of-thorns starfish Acanthaster planci venom." Ota E., Nagai H., Nagashima Y., Shiomi K. Comp. Biochem. Physiol. 143B:54-60(2006) [PubMed: 16275035] [Abstract] Cited for: NUCLEOTIDE SEQUENCE [MRNA], PROTEIN SEQUENCE OF 110-118 AND 127-156.
[2]	"Purification and properties of phospholipases A2 from the crown-of-thorns starfish (Acanthaster planci) venom." Shiomi K.A., Kazama A., Shimakura K., Nagashima Y. Toxicon 36:589-599(1998) [PubMed: 9643471] [Abstract] Cited for: PROTEIN SEQUENCE OF 24-85, FUNCTION. Tissue: Spine.

Cross-references

Sequence databases
EMBLGenBankDDBJ	AB211367 mRNA. Translation: BAE46765.1.
3D structure databases
ModBase	Search...
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.
ProDom	PD000303. PhospholipaseA2. 1 hit. [Graphical view] [Entries sharing at least one domain]
SMART	SM00085. PA2c. 1 hit. [Graphical view]
PROSITE	PS00119. PA2_ASP. False negative. PS00118. PA2_HIS. 1 hit. [Graphical view]
ProtoNet	Search...

Entry information

Entry name

PA21_ACAPL

Accession

Primary (citable) accession number: Q3C2C2

Entry history

Integrated into UniProtKB/Swiss-Prot:	January 9, 2007
Last sequence update:	November 22, 2005
Last modified:	November 25, 2008
This is version 21 of the entry and version 1 of the sequence. [Complete history]

Entry status

Reviewed (UniProtKB/Swiss-Prot)

Annotation project

Tox-Prot (Toxin Annotation Project)