P22640 · PA2H_PROMU
- ProteinBasic phospholipase A2 homolog
- StatusUniProtKB reviewed (Swiss-Prot)
- Amino acids122 (go to sequence)
- Protein existenceEvidence at protein level
- Annotation score4/5
Function
function
Snake venom phospholipase A2 (PLA2) that has almost no phospholipase A2 activity. Is myotoxic (By similarity).
Displays edema-inducing activities (PubMed:2029535).
A model of myotoxic mechanism has been proposed: an apo Lys49-PLA2 is activated by the entrance of a hydrophobic molecule (e.g. fatty acid) at the hydrophobic channel of the protein leading to a reorientation of a monomer (By similarity).
This reorientation causes a transition between 'inactive' to 'active' states, causing alignment of C-terminal and membrane-docking sites (MDoS) side-by-side and putting the membrane-disruption sites (MDiS) in the same plane, exposed to solvent and in a symmetric position for both monomers (By similarity).
The MDoS region stabilizes the toxin on membrane by the interaction of charged residues with phospholipid head groups (By similarity).
Subsequently, the MDiS region destabilizes the membrane with penetration of hydrophobic residues (By similarity).
This insertion causes a disorganization of the membrane, allowing an uncontrolled influx of ions (i.e. calcium and sodium), and eventually triggering irreversible intracellular alterations and cell death (By similarity).
Displays edema-inducing activities (PubMed:2029535).
A model of myotoxic mechanism has been proposed: an apo Lys49-PLA2 is activated by the entrance of a hydrophobic molecule (e.g. fatty acid) at the hydrophobic channel of the protein leading to a reorientation of a monomer (By similarity).
This reorientation causes a transition between 'inactive' to 'active' states, causing alignment of C-terminal and membrane-docking sites (MDoS) side-by-side and putting the membrane-disruption sites (MDiS) in the same plane, exposed to solvent and in a symmetric position for both monomers (By similarity).
The MDoS region stabilizes the toxin on membrane by the interaction of charged residues with phospholipid head groups (By similarity).
Subsequently, the MDiS region destabilizes the membrane with penetration of hydrophobic residues (By similarity).
This insertion causes a disorganization of the membrane, allowing an uncontrolled influx of ions (i.e. calcium and sodium), and eventually triggering irreversible intracellular alterations and cell death (By similarity).
Features
Showing features for site.
Type | ID | Position(s) | Description | |||
---|---|---|---|---|---|---|
Site | 106 | Important residue of the cationic membrane-docking site (MDoS) | ||||
Sequence: K | ||||||
Site | 109 | Important residue of the cationic membrane-docking site (MDoS) | ||||
Sequence: R | ||||||
Site | 112 | Cationic membrane-docking site (MDoS) | ||||
Sequence: V | ||||||
Site | 113 | Cationic membrane-docking site (MDoS) | ||||
Sequence: K | ||||||
Site | 115 | Hydrophobic membrane-disruption site (MDiS) | ||||
Sequence: L |
GO annotations
Aspect | Term | |
---|---|---|
Cellular Component | extracellular region | |
Molecular Function | calcium ion binding | |
Molecular Function | calcium-dependent phospholipase A2 activity | |
Molecular Function | phospholipid binding | |
Molecular Function | toxin activity | |
Biological Process | arachidonic acid secretion | |
Biological Process | lipid catabolic process | |
Biological Process | negative regulation of T cell proliferation | |
Biological Process | phospholipid metabolic process |
Keywords
- Molecular function
Names & Taxonomy
Protein names
- Recommended nameBasic phospholipase A2 homolog
- Short namessvPLA2 homolog
- Alternative names
Organism names
- Taxonomic lineageEukaryota > Metazoa > Chordata > Craniata > Vertebrata > Euteleostomi > Lepidosauria > Squamata > Bifurcata > Unidentata > Episquamata > Toxicofera > Serpentes > Colubroidea > Viperidae > Crotalinae > Protobothrops
Accessions
- Primary accessionP22640
Subcellular Location
PTM/Processing
Features
Showing features for chain, disulfide bond.
Type | ID | Position(s) | Description | |||
---|---|---|---|---|---|---|
Chain | PRO_0000161706 | 1-122 | Basic phospholipase A2 homolog | |||
Sequence: SLIELGKMIFQETGKNPVKNYGLYLCNCGVGNRGKPVDATDRCCFVHKCCYKKVTGCDPKKDRYSYSWENKAIVCGEKNPPCLKQVCECDKAVAICLRENLQTYDKKHRVTVKFLCKAPESC | ||||||
Disulfide bond | 26↔116 | |||||
Sequence: CNCGVGNRGKPVDATDRCCFVHKCCYKKVTGCDPKKDRYSYSWENKAIVCGEKNPPCLKQVCECDKAVAICLRENLQTYDKKHRVTVKFLC | ||||||
Disulfide bond | 28↔44 | |||||
Sequence: CGVGNRGKPVDATDRCC | ||||||
Disulfide bond | 43↔96 | |||||
Sequence: CCFVHKCCYKKVTGCDPKKDRYSYSWENKAIVCGEKNPPCLKQVCECDKAVAIC | ||||||
Disulfide bond | 49↔122 | |||||
Sequence: CCYKKVTGCDPKKDRYSYSWENKAIVCGEKNPPCLKQVCECDKAVAICLRENLQTYDKKHRVTVKFLCKAPESC | ||||||
Disulfide bond | 50↔89 | |||||
Sequence: CYKKVTGCDPKKDRYSYSWENKAIVCGEKNPPCLKQVCEC | ||||||
Disulfide bond | 57↔82 | |||||
Sequence: CDPKKDRYSYSWENKAIVCGEKNPPC | ||||||
Disulfide bond | 75↔87 | |||||
Sequence: CGEKNPPCLKQVC |
Keywords
- PTM
Expression
Tissue specificity
Expressed by the venom gland.
Interaction
Subunit
Homodimer; non-covalently linked.
Structure
Family & Domains
Features
Showing features for region.
Type | ID | Position(s) | Description | |||
---|---|---|---|---|---|---|
Region | 106-117 | Important for membrane-damaging activities in eukaryotes and bacteria; heparin-binding | ||||
Sequence: KKHRVTVKFLCK |
Sequence similarities
Family and domain databases
Sequence
- Sequence statusComplete
- Length122
- Mass (Da)13,809
- Last updated1991-08-01 v1
- Checksum96F567227B825E8B
Keywords
- Technical term