ID   3SA5_NAJKA              Reviewed;          60 AA.
AC   P24779;
DT   01-MAR-1992, integrated into UniProtKB/Swiss-Prot.
DT   01-MAR-1992, sequence version 1.
DT   25-MAY-2022, entry version 83.
DE   RecName: Full=Cytotoxin 5;
DE   AltName: Full=Cytotoxin II;
OS   Naja kaouthia (Monocled cobra) (Naja siamensis).
OC   Eukaryota; Metazoa; Chordata; Craniata; Vertebrata; Euteleostomi;
OC   Lepidosauria; Squamata; Bifurcata; Unidentata; Episquamata; Toxicofera;
OC   Serpentes; Colubroidea; Elapidae; Elapinae; Naja.
OX   NCBI_TaxID=8649;
RN   [1]
RP   PROTEIN SEQUENCE, AND SUBCELLULAR LOCATION.
RC   TISSUE=Venom;
RX   PubMed=3365434; DOI=10.1016/0167-4838(88)90065-9;
RA   Ohkura K., Inoue S., Ikeda K., Hayashi K.;
RT   "Amino-acid sequences of four cytotoxins (cytotoxins I, II, III and IV)
RT   purified from the venom of the Thailand cobra, Naja naja siamensis.";
RL   Biochim. Biophys. Acta 954:148-153(1988).
CC   -!- FUNCTION: Shows cytolytic activity on many different cells by forming
CC       pore in lipid membranes. In vivo, increases heart rate or kills the
CC       animal by cardiac arrest. In addition, it binds to heparin with high
CC       affinity, interacts with Kv channel-interacting protein 1 (KCNIP1) in a
CC       calcium-independent manner, and binds to integrin alpha-V/beta-3
CC       (ITGAV/ITGB3) with moderate affinity. {ECO:0000250|UniProtKB:P60301,
CC       ECO:0000250|UniProtKB:P60304}.
CC   -!- SUBUNIT: Monomer in solution; Homodimer and oligomer in the presence of
CC       negatively charged lipids forming a pore with a size ranging between 20
CC       and 30 Angstroms. {ECO:0000250|UniProtKB:P60301}.
CC   -!- SUBCELLULAR LOCATION: Secreted {ECO:0000269|PubMed:3365434}. Target
CC       cell membrane {ECO:0000250|UniProtKB:P60301}.
CC   -!- TISSUE SPECIFICITY: Expressed by the venom gland. {ECO:0000305}.
CC   -!- MISCELLANEOUS: Is classified as a P-type cytotoxin, since a proline
CC       residue stands at position 30 (Pro-31 in standard classification).
CC       {ECO:0000305}.
CC   -!- SIMILARITY: Belongs to the snake three-finger toxin family. Short-chain
CC       subfamily. Type IA cytotoxin sub-subfamily. {ECO:0000305}.
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DR   PIR; JS0028; JS0028.
DR   AlphaFoldDB; P24779; -.
DR   SMR; P24779; -.
DR   PRIDE; P24779; -.
DR   GO; GO:0005576; C:extracellular region; IEA:UniProtKB-SubCell.
DR   GO; GO:0016020; C:membrane; IEA:UniProtKB-KW.
DR   GO; GO:0090729; F:toxin activity; IEA:UniProtKB-KW.
DR   GO; GO:0019835; P:cytolysis; IEA:UniProtKB-KW.
DR   CDD; cd00206; snake_toxin; 1.
DR   Gene3D; 2.10.60.10; -; 1.
DR   InterPro; IPR003572; Cytotoxin_Cobra.
DR   InterPro; IPR003571; Snake_3FTx.
DR   InterPro; IPR045860; Snake_toxin-like_sf.
DR   InterPro; IPR018354; Snake_toxin_con_site.
DR   InterPro; IPR035076; Toxin/TOLIP.
DR   Pfam; PF00087; Toxin_TOLIP; 1.
DR   PRINTS; PR00282; CYTOTOXIN.
DR   SUPFAM; SSF57302; SSF57302; 1.
DR   PROSITE; PS00272; SNAKE_TOXIN; 1.
PE   1: Evidence at protein level;
KW   Cardiotoxin; Cytolysis; Direct protein sequencing; Disulfide bond;
KW   Membrane; Secreted; Target cell membrane; Target membrane; Toxin.
FT   CHAIN           1..60
FT                   /note="Cytotoxin 5"
FT                   /evidence="ECO:0000269|PubMed:3365434"
FT                   /id="PRO_0000093501"
FT   DISULFID        3..21
FT                   /evidence="ECO:0000250|UniProtKB:P60301"
FT   DISULFID        14..38
FT                   /evidence="ECO:0000250|UniProtKB:P60301"
FT   DISULFID        42..53
FT                   /evidence="ECO:0000250|UniProtKB:P60301"
FT   DISULFID        54..59
FT                   /evidence="ECO:0000250|UniProtKB:P60301"
SQ   SEQUENCE   60 AA;  6654 MW;  E53554A5E7F3AEB3 CRC64;
     LKCNKLIPLA YKTCPAGKNL CYKMFMVAAP KVPVKRGCID ACPKNSLLVK YVCCNTDRCN