P59888 · IPTXI_PANIM

Function

function

Phospholipase toxin, which may catalyze the calcium-dependent hydrolysis of the 2-acyl groups in 3-sn-phosphoglycerides. Inhibits both skeletal (RYR1) and cardiac (RYR2) ryanodine receptors (calcium release channels). Probably blocks ryanodine receptors by generating a lipid product.

Caution

In contrast to other phospholipases, it lacks the typical Asp active site (Asp->Glu in position 93).

Catalytic activity

Cofactor

Ca2+ (UniProtKB | Rhea| CHEBI:29108 )

Note: Binds 1 Ca2+ ion.

Features

Showing features for binding site, active site.

TypeIDPosition(s)Description
Binding site38Ca2+ (UniProtKB | ChEBI)
Binding site40Ca2+ (UniProtKB | ChEBI)
Binding site42Ca2+ (UniProtKB | ChEBI)
Active site64
Binding site65Ca2+ (UniProtKB | ChEBI)

GO annotations

AspectTerm
Cellular Componentextracellular region
Molecular Functioncalcium channel regulator activity
Molecular Functionmetal ion binding
Molecular Functionphospholipase A2 activity
Molecular Functiontoxin activity
Biological Processarachidonic acid secretion
Biological Processlipid catabolic process
Biological Processphospholipid metabolic process

Keywords

Names & Taxonomy

Protein names

Organism names

  • Taxonomic identifier
  • Taxonomic lineage
    Eukaryota > Metazoa > Ecdysozoa > Arthropoda > Chelicerata > Arachnida > Scorpiones > Iurida > Scorpionoidea > Scorpionidae > Pandininae > Pandinus

Accessions

  • Primary accession
    P59888

Subcellular Location

Keywords

Phenotypes & Variants

Features

Showing features for mutagenesis.

TypeIDPosition(s)Description
Mutagenesis144Does not affect the binding of ryanodine to cardiac ryanodine receptor.

PTM/Processing

Features

Showing features for propeptide, signal, chain, disulfide bond, glycosylation.

TypeIDPosition(s)Description
PropeptidePRO_0000022988?-31
Signal1-?
ChainPRO_000002298932-135Imperatoxin-1 large subunit
Disulfide bond39↔61
Disulfide bond60↔99
Disulfide bond67↔92
Disulfide bond90↔127
Glycosylation102N-linked (GlcNAc...) asparagine
Disulfide bond132↔144Interchain (between large and small subunits)
PropeptidePRO_0000022990136-140
ChainPRO_0000022991141-167Imperatoxin-1 small subunit

Keywords

Expression

Tissue specificity

Expressed by the venom gland.

Interaction

Subunit

Heterodimer composed of a large subunit and a small subunit; disulfide-linked.

Structure

Family & Domains

Sequence similarities

Keywords

Family and domain databases

Sequence

  • Sequence status
    Complete
  • Sequence processing
    The displayed sequence is further processed into a mature form.
  • Length
    167
  • Mass (Da)
    18,664
  • Last updated
    2003-09-26 v1
  • Checksum
    027420BFB033B18E
MHTPKHAIQRISKEEMEFFEGRCERMGEADETMWGTKWCGSGNEATDISELGYWSNLDSCCRTHDHCDNIPSGQTKYGLTNEGKYTMMNCKCETAFEQCLRNVTGGMEGPAAGFVRKTYFDLYGNGCYNVQCPSQRRLARSEECPDGVATYTGEAGYGAWAINKLNG

Keywords

Similar Proteins

Disclaimer

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