ID   CALB_CALS5              Reviewed;          39 AA.
AC   P60977;
DT   26-APR-2004, integrated into UniProtKB/Swiss-Prot.
DT   26-APR-2004, sequence version 1.
DT   25-MAY-2022, entry version 51.
DE   RecName: Full=U1-nemetoxin-Csp1b;
DE            Short=U1-NETX-Csp1b;
DE   AltName: Full=Toxic peptide B {ECO:0000303|Ref.1};
OS   Calisoga sp. (Spider).
OC   Eukaryota; Metazoa; Ecdysozoa; Arthropoda; Chelicerata; Arachnida; Araneae;
OC   Mygalomorphae; Nemesiidae; Calisoga; unclassified Calisoga.
OX   NCBI_TaxID=269418;
RN   [1]
RP   NUCLEOTIDE SEQUENCE [MRNA], PROTEIN SEQUENCE, TOXIC DOSE, AND MASS
RP   SPECTROMETRY.
RC   TISSUE=Venom, and Venom gland;
RA   Johnson J.H., Kral R.M. Jr., Krapcho K.;
RT   "Insecticidal peptides from spider venom.";
RL   Patent number US5688764, 18-NOV-1997.
CC   -!- FUNCTION: Causes paralysis to insect larvae (H.virescens). This toxin
CC       is active only on insects.
CC   -!- SUBCELLULAR LOCATION: Secreted.
CC   -!- TISSUE SPECIFICITY: Expressed by the venom gland.
CC   -!- DOMAIN: The presence of a 'disulfide through disulfide knot'
CC       structurally defines this protein as a knottin. {ECO:0000250}.
CC   -!- MASS SPECTROMETRY: Mass=4287.89; Method=Electrospray;
CC       Evidence={ECO:0000269|Ref.1};
CC   -!- TOXIC DOSE: PD(50) is 3.70 +/- 0.19 mg/kg by injection into the abdomen
CC       of larvae of H.virescens. {ECO:0000269|Ref.1}.
CC   -!- SIMILARITY: Belongs to the neurotoxin 13 (insecticidal toxin ABC)
CC       family. 02 (Calisoga) subfamily. {ECO:0000305}.
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DR   AlphaFoldDB; P60977; -.
DR   SMR; P60977; -.
DR   TCDB; 8.B.21.1.3; the spider insecticidal neurotoxin cyrtautoxin (cyrautoxin) family.
DR   ArachnoServer; AS000029; U1-nemetoxin-Csp1b.
DR   GO; GO:0005576; C:extracellular region; IEA:UniProtKB-SubCell.
DR   GO; GO:0090729; F:toxin activity; IEA:UniProtKB-KW.
DR   InterPro; IPR012626; Spider_insecticidal_peptide.
DR   Pfam; PF08091; Toxin_21; 1.
PE   1: Evidence at protein level;
KW   Direct protein sequencing; Disulfide bond; Knottin; Secreted; Toxin.
FT   PEPTIDE         1..39
FT                   /note="U1-nemetoxin-Csp1b"
FT                   /id="PRO_0000045036"
FT   DISULFID        1..15
FT                   /evidence="ECO:0000250|UniProtKB:P49268"
FT   DISULFID        8..19
FT                   /evidence="ECO:0000250|UniProtKB:P49268"
FT   DISULFID        14..36
FT                   /evidence="ECO:0000250|UniProtKB:P49268"
FT   DISULFID        25..32
FT                   /evidence="ECO:0000250|UniProtKB:P49268"
SQ   SEQUENCE   39 AA;  4296 MW;  34C7C761E84B8230 CRC64;
     CISARYPCSN SKDCCSGNCG TFWTCFIRKD PCSKECLAP