Q1RP79 (PA21P_VIPNI) Reviewed, UniProtKB/Swiss-Prot

Names and origin

Protein names	Recommended name: Phospholipase A2, chain HDP-1P EC=3.1.1.4 Alternative name(s): Heterodimeric neurotoxic phospholipases A2 basic subunit 1 Phosphatidylcholine 2-acylhydrolase
Organism	Vipera nikolskii (Nikolsky's adder)
Taxonomic identifier	110206 [NCBI]
Taxonomic lineage	Eukaryota › Metazoa › Chordata › Craniata › Vertebrata › Euteleostomi › Lepidosauria › Squamata › Scleroglossa › Serpentes › Colubroidea › Viperidae › Viperinae › Vipera

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. The monomeric form of HDP-1P affects neuromuscular transmission acting presynaptically. It has catalytic activity, anticoagulant activity and a ADP-induced platelet aggregation activity. The complex of HDP-1P and its inhibitor shows the same activities as the monomer, but with a lower potency. Ref.1
Catalytic activity	Phosphatidylcholine + H2O = 1-acylglycerophosphocholine + a carboxylate.
Cofactor	Binds 1 calcium ion per subunit By similarity.
Subunit structure	Heterodimer of a toxic basic protein having phospholipase A2 activity (chain HDP-1P) and a non-toxic acidic protein functioning as its inhibitor (chain HPD-1I).
Subcellular location	Secreted.
Tissue specificity	Expressed by the venom gland.
Sequence similarities	Belongs to the phospholipase A2 family. Group II subfamily.
Mass spectrometry	Molecular mass is 13798±1 Da from positions 17 - 138. Determined by MALDI. Ref.1

Ontologies

Keywords
Cellular component	Secreted
Domain	Signal
Ligand	Metal-binding
Molecular function	Hydrolase Neurotoxin Presynaptic neurotoxin Toxin
PTM	Disulfide bond
Technical term	3D-structure Direct protein sequencing
Gene Ontology (GO)
Biological process	lipid catabolic process Inferred from electronic annotation. Source: InterPro phospholipid metabolic process Inferred from electronic annotation. Source: InterPro
Cellular component	other organism presynaptic membrane 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: 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.1

Chain

17 – 138

122

Phospholipase A2, chain HDP-1P

PRO_5000079752

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

47

1

Calcium; via carbonyl oxygen By similarity

Metal binding

64

1

Calcium By similarity

Amino acid modifications

Disulfide bond

42 ↔ 131

Ref.2

Disulfide bond

44 ↔ 60

Ref.2

Disulfide bond

59 ↔ 111

Ref.2

Disulfide bond

65 ↔ 138

Ref.2

Disulfide bond

66 ↔ 104

Ref.2

Disulfide bond

73 ↔ 97

Ref.2

Disulfide bond

91 ↔ 102

Ref.2

Secondary structure

1

.

.

.

.

.

.

.

.

.

.

.

.

.

.

.

.

.

138

Helix Strand Turn

Details...

Helix

18 – 25

8

Helix

33 – 36

4

Helix

55 – 66

12

Turn

75 – 77

3

Helix

98 – 114

17

Helix

116 – 118

3

Helix

121 – 123

3

Helix

128 – 131

4

Sequences

	Sequence		Length	Mass (Da)
	Q1RP79 [UniParc]. Last modified May 16, 2006. Version 1. Checksum: 72D55BD516C3E5D9	FASTA	138	15,566
	10 20 30 40 50 60 MRILWIVAVC LIGVEGNLFQ FAKMINGKLG AFSVWNYISY GCYCGWGGQG TPKDATDRCC 70 80 90 100 110 120 FVHDCCYGRV RGCNPKLAIY AYSFKKGNIV CGKNNGCLRD ICECDRVAAN CFHQNQNTYN 130 KNYKFLSSSR CRQTSEQC

References

[1]

"Heterodimeric neurotoxic phospholipases A2 -- the first proteins from venom of recently established species Vipera nikolskii: implication of venom composition in viper systematics." Ramazanova A.S., Zavada L.L., Starkov V.G., Kovyazina I.V., Subbotina T.F., Kostyukhina E.E., Dementieva I.N., Ovchinnikova T.V., Utkin Y.N. Toxicon 51:524-537(2008) [PubMed: 18083205] [Abstract] Cited for: NUCLEOTIDE SEQUENCE [MRNA], PROTEIN SEQUENCE OF 17-32, FUNCTION, MASS SPECTROMETRY. Tissue: Venom and Venom gland.

[2]

"Crystal structures of phospholipases A2 from Vipera nikolskii venom revealing triton x-100 bound in hydrophobic channel." Gao W., Bi R.C. Submitted (SEP-2007) to the PDB data bank Cited for: X-RAY CRYSTALLOGRAPHY (2.2 ANGSTROMS) OF 17-138, DISULFIDE BONDS. Tissue: Venom.

Cross-references

Sequence databases

EMBL
GenBank
DDBJ

AM238698 mRNA. Translation: CAJ87658.1.

3D structure databases

PDBe
RCSB PDB
PDBj

Entry	Method	Resolution (Å)	Chain	Positions	PDBsum
2I0U	X-ray	2.20	A/E	17-138	[»]

ProteinModelPortal

Q1RP79.

SMR

Q1RP79. Positions 17-138.

ModBase

Search...

Protocols and materials databases

StructuralBiologyKnowledgebase

Search...

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

PA21P_VIPNI

Accession

Primary (citable) accession number: Q1RP79

Entry history

Integrated into UniProtKB/Swiss-Prot:	May 5, 2009
Last sequence update:	May 16, 2006
Last modified:	November 16, 2011
This is version 35 of the entry and version 1 of the sequence. [Complete history]

Entry status

Reviewed (UniProtKB/Swiss-Prot)

Annotation program

Chordata Protein Annotation Program

Annotation program

Animal Toxin Annotation Program