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G9I930 (PA2HB_MICTN) Reviewed, UniProtKB/Swiss-Prot

Last modified May 14, 2014. Version 17. Feed History...

Clusters with 100%, 90%, 50% identity | Documents (3) | Third-party data text xml rdf/xml gff fasta
to top of pageNames·Attributes·General annotation·Ontologies·Sequence annotation·Sequences·References·Web links·Cross-refs·Entry info·DocumentsCustomize order

Names and origin

Protein namesRecommended name:
Basic phospholipase A2 homolog Tx-beta

Short name=svPLA2 homolog
Alternative name(s):
MitTx-beta
OrganismMicrurus tener tener (Texas coral snake)
Taxonomic identifier1114302 [NCBI]
Taxonomic lineageEukaryotaMetazoaChordataCraniataVertebrataEuteleostomiLepidosauriaSquamataBifurcataUnidentataEpisquamataToxicoferaSerpentesColubroideaElapidaeElapinaeMicrurus

Protein attributes

Sequence length149 AA.
Sequence statusComplete.
Sequence processingThe displayed sequence is further processed into a mature form.
Protein existenceEvidence at protein level

General annotation (Comments)

Function

Heterodimer: snake venom phospholipase that potently activates mouse H+-gated sodium channel ASIC1/ACCN2 (acid-sensitive ion channel 1) expressed in Xenopus oocytes. Both alternatively spliced isoforms ASIC1a and ASIC1b are activated, with a higher potency for ASIC1a (EC50=9.4 nM) vs ASIC1b (EC50=23 nM). The ASIC3/ACCN3 subtype is also sensitive to the heterodimer, but with a lower potency (EC50=830 nM). On ASIC2a/ACCN1, the toxin shows a very weak activation, but produces a remarkable potentiation (>100-fold) of protons when the extracellular pH drops below neutrality. The toxin interacts with the extracellular region of the channel, since responses are only observed in the outside-out configuration. In vivo, the heterodimer elicits robust pain-related behavior in mice by activation of ASIC1/ACCN2 channels on capsaicin-sensitive nerve fibers. Ref.1

Monomer: does not have phospholipase A2 activity but may maintain some lipid-binding character from its PLA2 lineage, which could aid in effecting neuronal depolarization. Ref.1

Subunit structure

Heterodimer of an alpha and a beta chains. Ref.1

Subcellular location

Secreted.

Tissue specificity

Expressed by the venom gland.

Miscellaneous

This toxin has been studied to probe molecular mechanisms underlying pain sensation. By targeting ASIC1/ACCN2, it reveals an unexpected contribution of this channel to nociception.

The heterodimeric toxin does not affect ASIC2b/ACCN1, ASIC4/ACCN4, Kv2.1/KCNB1, Cav3.3/CACNA1I, ENaC/SCNN1A, TRPA1, TRPV1, TRPV3, TRPM8, P2X2/P2RX2, and 5-HT3/HTR3A channels (Ref.1).

Sequence similarities

Belongs to the phospholipase A2 family. Group I subfamily. K49 sub-subfamily.

Ontologies

Keywords
   Cellular componentSecreted
   DomainSignal
   Molecular functionIon channel impairing toxin
Neurotoxin
Toxin
   PTMDisulfide bond
   Technical term3D-structure
Direct protein sequencing
Gene Ontology (GO)
   Biological_processlipid catabolic process

Inferred from electronic annotation. Source: InterPro

phospholipid metabolic process

Inferred from electronic annotation. Source: InterPro

   Cellular_componentextracellular region

Inferred from electronic annotation. Source: UniProtKB-SubCell

   Molecular_functioncalcium ion binding

Inferred from electronic annotation. Source: InterPro

phospholipase A2 activity

Inferred from electronic annotation. Source: InterPro

Complete GO annotation...

Sequence annotation (Features)

Feature keyPosition(s)LengthDescriptionGraphical viewFeature identifier

Molecule processing

Signal peptide1 – 3030 Ref.1
Chain31 – 149119Basic phospholipase A2 homolog Tx-beta
PRO_5000828218

Amino acid modifications

Disulfide bond41 ↔ 100 By similarity
Disulfide bond55 ↔ 148 By similarity
Disulfide bond57 ↔ 73 By similarity
Disulfide bond72 ↔ 130 By similarity
Disulfide bond79 ↔ 123 By similarity
Disulfide bond89 ↔ 116 By similarity
Disulfide bond109 ↔ 121 By similarity

Secondary structure

.................... 149
Helix Strand Turn

Details...

Sequences

Sequence LengthMass (Da)Tools
G9I930 [UniParc].

Last modified February 22, 2012. Version 1.
Checksum: 4CF027CBCA751BE4

FASTA14916,793
        10         20         30         40         50         60 
MDKMNPAHLL VLAAVCVSLL GASSIPPQAL NLNQFRLMIK CTNDRVWADF VDYGCYCVAR 

        70         80         90        100        110        120 
DSNTPVDDLD RCCQAQKQCY DEAVKVHGCK PLVMFYSFEC RYLASDLDCS GNNTKCRNFV 

       130        140 
CNCDRTATLC ILTATYNRNN HKIDPSRCQ 

« Hide

References

[1]"A heteromeric Texas coral snake toxin targets acid-sensing ion channels to produce pain."
Bohlen C.J., Chesler A.T., Sharif-Naeini R., Medzihradszky K.F., Zhou S., King D., Sanchez E.E., Burlingame A.L., Basbaum A.I., Julius D.
Nature 479:410-414(2011) [PubMed] [Europe PMC] [Abstract]
Cited for: NUCLEOTIDE SEQUENCE [MRNA], PROTEIN SEQUENCE OF N-TERMINUS, FUNCTION, SUBUNIT.
Tissue: Venom and Venom gland.
+Additional computationally mapped references.

Web resources

Protein Spotlight

The poison in pain - Issue 140 of July 2012

Cross-references

Sequence databases

EMBL
GenBank
DDBJ
JN613326 mRNA. Translation: AET85560.1.

3D structure databases

PDBe
RCSB-PDB
PDBj
EntryMethodResolution (Å)ChainPositionsPDBsum
4NTWX-ray2.07C31-149[»]
4NTXX-ray2.27C31-149[»]
4NTYX-ray2.65C31-149[»]
ProteinModelPortalG9I930.
ModBaseSearch...
MobiDBSearch...

Protocols and materials databases

StructuralBiologyKnowledgebaseSearch...

Family and domain databases

Gene3D1.20.90.10. 1 hit.
InterProIPR001211. PLipase_A2.
IPR013090. PLipase_A2_AS.
IPR016090. PLipase_A2_dom.
[Graphical view]
PANTHERPTHR11716. PTHR11716. 1 hit.
PfamPF00068. Phospholip_A2_1. 1 hit.
[Graphical view]
PRINTSPR00389. PHPHLIPASEA2.
SMARTSM00085. PA2c. 1 hit.
[Graphical view]
SUPFAMSSF48619. SSF48619. 1 hit.
PROSITEPS00119. PA2_ASP. 1 hit.
[Graphical view]
ProtoNetSearch...

Entry information

Entry namePA2HB_MICTN
AccessionPrimary (citable) accession number: G9I930
Entry history
Integrated into UniProtKB/Swiss-Prot: April 18, 2012
Last sequence update: February 22, 2012
Last modified: May 14, 2014
This is version 17 of the entry and version 1 of the sequence. [Complete history]
Entry statusReviewed (UniProtKB/Swiss-Prot)
Annotation programAnimal Toxin Annotation Program
Annotation programChordata Protein Annotation Program

Relevant documents

SIMILARITY comments

Index of protein domains and families

Protein Spotlight

Protein Spotlight articles and cited UniProtKB/Swiss-Prot entries

PDB cross-references

Index of Protein Data Bank (PDB) cross-references