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P01525 (NXB4_CERLA) Reviewed, UniProtKB/Swiss-Prot

Last modified October 16, 2013. Version 77. Feed History...

Clusters with 100%, 90%, 50% identity | Documents (2) | Third-party data text xml rdf/xml gff fasta
to top of pageNames·Attributes·General annotation·Ontologies·Sequence annotation·Sequences·References·Cross-refs·Entry info·DocumentsCustomize order

Names and origin

Protein namesRecommended name:
Neurotoxin B-IV
OrganismCerebratulus lacteus (Milky ribbon worm) (Micrura lactea)
Taxonomic identifier6221 [NCBI]
Taxonomic lineageEukaryotaMetazoaLophotrochozoaNemerteaAnoplaHeteronemerteaCerebratulidaeCerebratulus

Protein attributes

Sequence length55 AA.
Sequence statusComplete.
Protein existenceEvidence at protein level

General annotation (Comments)

Function

This toxin increases the excitability of nerves by delaying the inactivation of the voltage-gated sodium channel (Nav). Only acts on some crustacean. Neurotoxin B-IV is more abundant, but 15-fold less toxic than neurotoxin B-II.

Subcellular location

Secreted.

Sequence similarities

Belongs to the worm B-toxin family.

Ontologies

Keywords
   Cellular componentSecreted
   Molecular functionIon channel impairing toxin
Toxin
Voltage-gated sodium channel impairing toxin
   PTMDisulfide bond
Hydroxylation
   Technical term3D-structure
Direct protein sequencing
Gene Ontology (GO)
   Biological_processpathogenesis

Inferred from electronic annotation. Source: InterPro

   Cellular_componentextracellular region

Inferred from electronic annotation. Source: UniProtKB-SubCell

   Molecular_functionsodium channel inhibitor activity

Inferred from electronic annotation. Source: InterPro

Complete GO annotation...

Sequence annotation (Features)

Feature keyPosition(s)LengthDescriptionGraphical viewFeature identifier

Molecule processing

Chain1 – 5555Neurotoxin B-IV
PRO_0000221572

Amino acid modifications

Modified residue101Hydroxyproline Ref.1
Disulfide bond12 ↔ 48 Ref.1
Disulfide bond16 ↔ 52 Ref.1
Disulfide bond23 ↔ 41 Ref.1
Disulfide bond26 ↔ 37 Ref.1

Experimental info

Mutagenesis91Y → F: 5-fold decrease in toxicity. Ref.4
Mutagenesis131E → A: No change in toxicity. Ref.4
Mutagenesis131E → Q: No change in toxicity. Ref.4
Mutagenesis171R → A: Complete loss of toxicity. Ref.4
Mutagenesis171R → K: Complete loss of toxicity. Ref.4
Mutagenesis171R → Q: Complete loss of toxicity. Ref.4
Mutagenesis18 – 192KK → QQ: Very low decrease in toxicity. Ref.5
Mutagenesis181K → Q: No change in toxicity. Ref.5
Mutagenesis211D → A: No change in toxicity. Ref.4
Mutagenesis211D → N: No change in toxicity. Ref.4
Mutagenesis211D → P: 10-fold decrease in toxicity. Ref.4
Mutagenesis221L → D: No change in toxicity. Ref.5
Mutagenesis251R → K: No change in toxicity. Ref.4
Mutagenesis251R → Q: 400-fold decrease in toxicity. Ref.4
Mutagenesis291K → N: No change in toxicity. Ref.5
Mutagenesis301W → F: No change in toxicity. Ref.5
Mutagenesis301W → S: 41-fold decrease in toxicity. Ref.5
Mutagenesis301W → Y: 5-fold decrease in toxicity. Ref.5
Mutagenesis331K → N: No decrease in toxicity. Ref.5
Mutagenesis341R → A: 80-fold decrease in toxicity. Ref.4
Mutagenesis341R → K: 8-fold decrease in toxicity. Ref.4
Mutagenesis341R → Q: 20-fold decrease in toxicity. Ref.4

Secondary structure

......... 55
Helix Strand Turn

Details...

Sequences

Sequence LengthMass (Da)Tools
P01525 [UniParc].

Last modified July 21, 1986. Version 1.
Checksum: BB76B72E48DB050D

FASTA556,107
        10         20         30         40         50 
ASATWGAAYP ACENNCRKKY DLCIRCQGKW AGKRGKCAAH CIIQKNNCKG KCKKE 

« Hide

References

[1]"Structure and action of heteronemertine polypeptide toxins. Amino acid sequence of Cerebratulus lacteus toxin B-II and revised structure of toxin B-IV."
Blumenthal K.M., Keim P.S., Heinrikson R.L., Kem W.R.
J. Biol. Chem. 256:9063-9067(1981) [PubMed] [Europe PMC] [Abstract]
Cited for: PROTEIN SEQUENCE, SEQUENCE REVISION.
[2]"Structure and action of heteronemertine polypeptide toxins. Primary structure of Cerebratulus lacteus toxin B-IV."
Blumenthal K.M., Kem W.R.
J. Biol. Chem. 251:6025-6029(1976) [PubMed] [Europe PMC] [Abstract]
Cited for: PROTEIN SEQUENCE.
[3]"Mutagenesis of Cerebratulus lacteus neurotoxin B-IV identifies NH2-terminal sequences important for biological activity."
Howell M.L., Blumenthal K.M.
J. Biol. Chem. 266:12884-12888(1991) [PubMed] [Europe PMC] [Abstract]
Cited for: MUTAGENESIS.
[4]"Role of electrostatic interactions in defining the potency of neurotoxin B-IV from Cerebratulus lacteus."
Wen P.H., Blumenthal K.M.
J. Biol. Chem. 271:29752-29758(1996) [PubMed] [Europe PMC] [Abstract]
Cited for: MUTAGENESIS OF TYR-9; GLU-13; ARG-17; ASP-21; ARG-25 AND ARG-34.
[5]"Structure and function of Cerebratulus lacteus neurotoxin B-IV: tryptophan-30 is critical for function while lysines-18, -19, -29, and -33 are not required."
Wen P.H., Blumenthal K.M.
Biochemistry 36:13435-13440(1997) [PubMed] [Europe PMC] [Abstract]
Cited for: MUTAGENESIS OF LYS-18; 18-LYS-LYS-19; LEU-22; LYS-29; TRP-30 AND LYS-33.
[6]"1H-NMR study of neurotoxin B-IV from the marine worm Cerebratulus lacteus. Solution properties, sequence-specific resonance assignments, secondary structure and global fold."
Hansen P.E., Kem W.R., Bieber A.L., Norton R.S.
Eur. J. Biochem. 210:231-240(1992) [PubMed] [Europe PMC] [Abstract]
Cited for: STRUCTURE BY NMR.
[7]"Structure of neurotoxin B-IV from the marine worm Cerebratulus lacteus: a helical hairpin cross-linked by disulphide bonding."
Barnham K.J., Dyke T.R., Kem W.R., Norton R.S.
J. Mol. Biol. 268:886-902(1997) [PubMed] [Europe PMC] [Abstract]
Cited for: STRUCTURE BY NMR.

Cross-references

Sequence databases

PIRNTHNB4. A92340.

3D structure databases

PDBe
RCSB PDB
PDBj
EntryMethodResolution (Å)ChainPositionsPDBsum
1VIBNMR-A1-55[»]
ProteinModelPortalP01525.
SMRP01525. Positions 1-44.
ModBaseSearch...
MobiDBSearch...

Protocols and materials databases

StructuralBiologyKnowledgebaseSearch...

Family and domain databases

Gene3D1.10.287.120. 1 hit.
InterProIPR012497. Neurotoxin_B-IV.
[Graphical view]
PfamPF07822. Toxin_13. 1 hit.
[Graphical view]
SUPFAMSSF57011. SSF57011. 1 hit.
ProtoNetSearch...

Other

EvolutionaryTraceP01525.

Entry information

Entry nameNXB4_CERLA
AccessionPrimary (citable) accession number: P01525
Entry history
Integrated into UniProtKB/Swiss-Prot: July 21, 1986
Last sequence update: July 21, 1986
Last modified: October 16, 2013
This is version 77 of the entry and version 1 of the sequence. [Complete history]
Entry statusReviewed (UniProtKB/Swiss-Prot)
Annotation programAnimal Toxin Annotation Program

Relevant documents

SIMILARITY comments

Index of protein domains and families

PDB cross-references

Index of Protein Data Bank (PDB) cross-references