ID   SPN2B_OXYTA             Reviewed;         171 AA.
AC   P86719; S4TYZ4;
DT   19-MAR-2014, integrated into UniProtKB/Swiss-Prot.
DT   19-MAR-2014, sequence version 1.
DT   25-MAY-2022, entry version 14.
DE   RecName: Full=Spiderine-2b {ECO:0000303|PubMed:24118933};
DE   AltName: Full=M-oxotoxin-Ot3k {ECO:0000305};
DE            Short=M-OXTX-Ot3k {ECO:0000305};
DE   AltName: Full=OtTx2b {ECO:0000303|PubMed:24118933};
DE   Flags: Precursor;
OS   Oxyopes takobius (Lynx spider) (Oxyopes foliiformis).
OC   Eukaryota; Metazoa; Ecdysozoa; Arthropoda; Chelicerata; Arachnida; Araneae;
OC   Araneomorphae; Entelegynae; Lycosoidea; Oxyopidae; Oxyopes.
OX   NCBI_TaxID=666126;
RN   [1]
RP   NUCLEOTIDE SEQUENCE [MRNA].
RC   TISSUE=Venom gland;
RX   PubMed=24118933; DOI=10.1111/febs.12547;
RA   Vassilevski A.A., Sachkova M.Y., Ignatova A.A., Kozlov S.A., Feofanov A.V.,
RA   Grishin E.V.;
RT   "Spider toxins comprising disulfide-rich and linear amphipathic domains: A
RT   new class of molecules identified in the lynx spider Oxyopes takobius.";
RL   FEBS J. 280:6247-6261(2013).
CC   -!- FUNCTION: Has antimicrobial, insecticidal, cytolytic and cytotoxic
CC       activity. {ECO:0000250|UniProtKB:P86716}.
CC   -!- SUBCELLULAR LOCATION: Secreted {ECO:0000250|UniProtKB:P86718}.
CC   -!- TISSUE SPECIFICITY: Expressed by the venom gland.
CC       {ECO:0000305|PubMed:24118933}.
CC   -!- DOMAIN: The presence of a 'disulfide through disulfide knot'
CC       structurally defines this protein as a knottin.
CC       {ECO:0000250|UniProtKB:P86716}.
CC   -!- DOMAIN: The N-terminal part of the mature protein (59-105) probably
CC       forms an alpha-helix which acts as a membrane-active peptide. It is
CC       necessary and sufficient for the toxin's antimicrobial, insecticidal,
CC       cytolytic and cytotoxic activity. {ECO:0000250|UniProtKB:P86716}.
CC   -!- SIMILARITY: Belongs to the spiderine family. Cationic/spiderine
CC       subfamily. {ECO:0000305}.
CC   ---------------------------------------------------------------------------
CC   Copyrighted by the UniProt Consortium, see https://www.uniprot.org/terms
CC   Distributed under the Creative Commons Attribution (CC BY 4.0) License
CC   ---------------------------------------------------------------------------
DR   EMBL; JX134897; AGG39776.1; -; mRNA.
DR   AlphaFoldDB; P86719; -.
DR   SMR; P86719; -.
DR   ArachnoServer; AS001889; M-oxotoxin-Ot3k.
DR   GO; GO:0005576; C:extracellular region; IEA:UniProtKB-SubCell.
DR   GO; GO:0090729; F:toxin activity; IEA:UniProtKB-KW.
DR   GO; GO:0019835; P:cytolysis; IEA:UniProtKB-KW.
DR   GO; GO:0042742; P:defense response to bacterium; IEA:UniProtKB-KW.
DR   InterPro; IPR044061; OXYTX_ICK.
DR   PROSITE; PS51861; OXYTX_ICK; 1.
PE   2: Evidence at transcript level;
KW   Antibiotic; Antimicrobial; Cytolysis; Disulfide bond; Knottin; Secreted;
KW   Signal; Toxin.
FT   SIGNAL          1..18
FT                   /evidence="ECO:0000255"
FT   PROPEP          19..58
FT                   /note="Removed in mature form"
FT                   /evidence="ECO:0000250|UniProtKB:P86718"
FT                   /id="PRO_0000425698"
FT   CHAIN           59..171
FT                   /note="Spiderine-2b"
FT                   /evidence="ECO:0000250|UniProtKB:P86718"
FT                   /id="PRO_0000425699"
FT   DOMAIN          118..171
FT                   /note="Oxytoxin-type inhibitor cystine knot (ICK)"
FT                   /evidence="ECO:0000255|PROSITE-ProRule:PRU01208"
FT   REGION          59..104
FT                   /note="Linear cationic cytotoxin domain"
FT                   /evidence="ECO:0000250|UniProtKB:P86716"
FT   DISULFID        121..135
FT                   /evidence="ECO:0000250|UniProtKB:P86716"
FT   DISULFID        128..140
FT                   /evidence="ECO:0000250|UniProtKB:P86716"
FT   DISULFID        132..167
FT                   /evidence="ECO:0000250|UniProtKB:P86716"
FT   DISULFID        134..156
FT                   /evidence="ECO:0000250|UniProtKB:P86716"
FT   DISULFID        142..154
FT                   /evidence="ECO:0000250|UniProtKB:P86716"
SQ   SEQUENCE   171 AA;  18889 MW;  55BEAE48C103EA02 CRC64;
     MKFALVLLGF CAFYLVNATG DLETELEASD LQELQEALDL IAETPLESLE AEELEEARKF
     KFPKINWGKL ASKAKDVYKK GQKLAKNKNV KKALKYGKQL AENLAAGEVH EPGTPVGNNK
     CWAIGTRCTD DCDCCPEHHC HCPAKSWTFG LIPCSCQVTE SDKVNKCPPA E