O57385 · PA2H_DEIAC

Function

function

Snake venom phospholipase A2 homolog that lacks enzymatic activity (PubMed:10930841).
Is myotoxic (By similarity).
Has a strong indirect hemolytic activity and anticoagulant activity (PubMed:10930841).
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).

Caution

Does not bind calcium as one of the calcium-binding sites is lost (Asp->Lys in position 64, which corresponds to 'Lys-49' in the current nomenclature).

Features

Showing features for site.

TypeIDPosition(s)Description
Site121Important residue of the cationic membrane-docking site (MDoS)
Site124Important residue of the cationic membrane-docking site (MDoS)
Site127Hydrophobic membrane-disruption site (MDiS)
Site128Cationic membrane-docking site (MDoS)
Site133Cationic membrane-docking site (MDoS)

GO annotations

AspectTerm
Cellular Componentextracellular region
Molecular Functioncalcium ion binding
Molecular Functioncalcium-dependent phospholipase A2 activity
Molecular Functionphospholipid binding
Molecular Functiontoxin activity
Biological Processarachidonic acid secretion
Biological Processlipid catabolic process
Biological Processnegative regulation of T cell proliferation
Biological Processphospholipid metabolic process

Keywords

Names & Taxonomy

Protein names

  • Recommended name
    Basic phospholipase A2 homolog acutohaemolysin
  • Short names
    svPLA2 homolog
  • Alternative names
    • Dac-K49

Organism names

Accessions

  • Primary accession
    O57385
  • Secondary accessions
    • Q8UVZ5

Subcellular Location

Keywords

PTM/Processing

Features

Showing features for signal, chain, disulfide bond.

Type
IDPosition(s)Description
Signal1-16
ChainPRO_000002277417-138Basic phospholipase A2 homolog acutohaemolysin
Disulfide bond42↔131
Disulfide bond44↔60
Disulfide bond59↔111
Disulfide bond65↔138
Disulfide bond66↔104
Disulfide bond73↔97
Disulfide bond91↔102

Keywords

Expression

Tissue specificity

Expressed by the venom gland.

Interaction

Subunit

Monomer.

Family & Domains

Features

Showing features for region.

TypeIDPosition(s)Description
Region121-133Important for membrane-damaging activities in eukaryotes and bacteria; heparin-binding

Sequence similarities

Keywords

Family and domain databases

Sequence

  • Sequence status
    Complete
  • Sequence processing
    The displayed sequence is further processed into a mature form.
  • Length
    138
  • Mass (Da)
    15,777
  • Last updated
    1998-06-01 v1
  • Checksum
    1353CD8C8F54DA99
MRALWIVAVLLVGVEGSLFELGKMIWQETGKNPVKNYGLYGCNCGVGGRGEPLDATDRCCFVHKCCYKKLTDCDSKKDRYSYKWKNKAIVCGKNQPCMQEMCECDKAFAICLRENLDTYNKSFRYHLKPSCKKTSEQC

Features

Showing features for sequence conflict.

TypeIDPosition(s)Description
Sequence conflict130in Ref. 2; AAL36975

Mass Spectrometry

Molecular mass is 13,938 Da. Determined by Electrospray.

Keywords

Sequence databases

Nucleotide SequenceProtein SequenceMolecule TypeStatus
AJ223188
EMBL· GenBank· DDBJ
CAA11159.1
EMBL· GenBank· DDBJ
mRNA
AF269132
EMBL· GenBank· DDBJ
AAL36975.1
EMBL· GenBank· DDBJ
mRNA

Similar Proteins

Disclaimer

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