P51972 (PA21_AGKPI) Reviewed, UniProtKB/Swiss-Prot

Names and origin

Protein names	Recommended name: Phospholipase A2 EC=3.1.1.4 Alternative name(s): APP-D-49 Phosphatidylcholine 2-acylhydrolase
Organism	Agkistrodon piscivorus piscivorus (Eastern cottonmouth)
Taxonomic identifier	8716 [NCBI]
Taxonomic lineage	Eukaryota › Metazoa › Chordata › Craniata › Vertebrata › Euteleostomi › Lepidosauria › Squamata › Scleroglossa › Serpentes › Colubroidea › Viperidae › Crotalinae › Agkistrodon

Protein attributes

Sequence length	123 AA.
Sequence status	Complete.
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.
Catalytic activity	Phosphatidylcholine + H2O = 1-acylglycerophosphocholine + a carboxylate.
Cofactor	Binds 1 calcium ion per subunit.
Subunit structure	Monomer or homodimer.
Subcellular location	Secreted.
Tissue specificity	Expressed by the venom gland.
Post-translational modification	Acylation causes dimerization.
Sequence similarities	Belongs to the phospholipase A2 family. Group II subfamily.

Ontologies

Keywords
Biological process	Lipid degradation
Cellular component	Secreted
Ligand	Calcium Metal-binding
Molecular function	Hydrolase
PTM	Disulfide bond Lipoprotein Palmitate
Technical term	3D-structure Direct protein sequencing
Gene Ontology (GO)
Biological process	lipid catabolic process 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: InterPro 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

Chain

1 – 123

123

Phospholipase A2

PRO_0000161605

Sites

Active site

47

1

By similarity

Active site

89

1

By similarity

Metal binding

27

1

Calcium; via carbonyl oxygen

Metal binding

29

1

Calcium; via carbonyl oxygen

Metal binding

31

1

Calcium; via carbonyl oxygen

Metal binding

48

1

Calcium

Amino acid modifications

Lipidation

7

1

N6-palmitoyl lysine Ref.2

Lipidation

10

1

N6-palmitoyl lysine Ref.2

Disulfide bond

26 ↔ 116

Disulfide bond

28 ↔ 44

Disulfide bond

43 ↔ 95

Disulfide bond

49 ↔ 123

Disulfide bond

50 ↔ 88

Disulfide bond

57 ↔ 81

Disulfide bond

75 ↔ 86

Secondary structure

1

.

.

.

.

.

.

.

.

.

.

.

.

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.

.

.

.

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.

.

.

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123

Helix Strand Turn

Details...

Helix

2 – 13

12

Helix

17 – 20

4

Beta strand

21 – 24

4

Turn

25 – 27

3

Beta strand

28 – 30

3

Helix

39 – 52

14

Turn

59 – 61

3

Beta strand

66 – 69

4

Beta strand

72 – 75

4

Helix

80 – 98

19

Helix

100 – 102

3

Helix

105 – 108

4

Helix

113 – 115

3

Sequences

	Sequence		Length	Mass (Da)
	P51972 [UniParc]. Last modified July 15, 1998. Version 2. Checksum: C39986552D990D72	FASTA	123	13,989
	10 20 30 40 50 60 NLFQFEKLIK KMTGKSGMLW YSAYGCYCGW GGQGRPKDAT DRCCFVHDCC YGKVTGCNPK 70 80 90 100 110 120 MDIYTYSVDN GNIVCGGTNP CKKQICECDR AAAICFRDNL KTYDSKTYWK YPKKNCKEES EPC

References

[1]	"An examination of structural interactions presumed to be of importance in the stabilization of phospholipase A2 dimers based upon comparative protein sequence analysis of a monomeric and dimeric enzyme from the venom of Agkistrodon p. piscivorus." Welches W., Reardon I.M., Heinrikson R.L. J. Protein Chem. 12:187-193(1993) [PubMed: 8489705] [Abstract] Cited for: PROTEIN SEQUENCE. Tissue: Venom.
[2]	"The chemical basis for interfacial activation of monomeric phospholipases A2. Autocatalytic derivatization of the enzyme by acyl transfer from substrate." Cho W., Tomasselli A.G., Heinrikson R.L., Kezdy F.J. J. Biol. Chem. 263:11237-11241(1988) [PubMed: 3403524] [Abstract] Cited for: PROTEIN SEQUENCE OF 1-23, PALMITOYLATION AT LYS-7 AND LYS-10. Tissue: Venom.
[3]	"A new class of phospholipases A2 with lysine in place of aspartate 49. Functional consequences for calcium and substrate binding." Maraganore J.M., Merutka G., Cho W., Welches W., Kezdy F.J., Heinrikson R.L. J. Biol. Chem. 259:13839-13843(1984) [PubMed: 6438084] [Abstract] Cited for: CHARACTERIZATION. Tissue: Venom.
[4]	"Structural aspects of interfacial adsorption. A crystallographic and site-directed mutagenesis study of the phospholipase A2 from the venom of Agkistrodon piscivorus piscivorus." Han S.K., Yoon E.T., Scott D.L., Sigler P.B., Cho W. J. Biol. Chem. 272:3573-3582(1997) [PubMed: 9013608] [Abstract] Cited for: X-RAY CRYSTALLOGRAPHY (1.6 ANGSTROMS). Tissue: Venom.
+	Additional computationally mapped references.

Cross-references

Sequence databases

PIR

B53872.

3D structure databases

PDBe
RCSB PDB
PDBj

Entry	Method	Resolution (Å)	Chain	Positions	PDBsum
1VAP	X-ray	1.60	A/B	1-123	[»]

ProteinModelPortal

P51972.

SMR

P51972. Positions 1-123.

ModBase

Search...

Protocols and materials databases

StructuralBiologyKnowledgebase

Search...

Phylogenomic databases

HOVERGEN

HBG008137.

Family and domain databases

InterPro

IPR016090. PLipase_A2.
IPR013090. PLipase_A2_AS.
IPR001211. PLipase_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]

SUPFAM

SSF48619. PhospholipaseA2. 1 hit.

PROSITE

PS00119. PA2_ASP. 1 hit.
PS00118. PA2_HIS. 1 hit.
[Graphical view]

ProtoNet

Search...

Entry information

Entry name

PA21_AGKPI

Accession

Primary (citable) accession number: P51972

Entry history

Integrated into UniProtKB/Swiss-Prot:	October 1, 1996
Last sequence update:	July 15, 1998
Last modified:	October 19, 2011
This is version 78 of the entry and version 2 of the sequence. [Complete history]

Entry status

Reviewed (UniProtKB/Swiss-Prot)

Annotation program

Chordata Protein Annotation Program