ID   3SA3A_NAJNA             Reviewed;          30 AA.
AC   P86539;
DT   15-JUN-2010, integrated into UniProtKB/Swiss-Prot.
DT   15-JUN-2010, sequence version 1.
DT   03-AUG-2022, entry version 26.
DE   RecName: Full=Cytotoxin 3a;
DE            Short=CTX3a;
DE   Flags: Fragment;
OS   Naja naja (Indian cobra).
OC   Eukaryota; Metazoa; Chordata; Craniata; Vertebrata; Euteleostomi;
OC   Lepidosauria; Squamata; Bifurcata; Unidentata; Episquamata; Toxicofera;
OC   Serpentes; Colubroidea; Elapidae; Elapinae; Naja.
OX   NCBI_TaxID=35670;
RN   [1]
RP   PROTEIN SEQUENCE, AND SUBCELLULAR LOCATION.
RC   TISSUE=Venom;
RX   PubMed=20203422; DOI=10.2220/biomedres.31.71;
RA   Suzuki M., Itoh T., Bandaranayake B.M.A.I.K., Ranasinghe J.G.,
RA   Athauda S.B., Moriyama A.;
RT   "Molecular diversity in venom proteins of the Russell's viper (Daboia
RT   russellii russellii) and the Indian cobra (Naja naja) in Sri Lanka.";
RL   Biomed. Res. 31:71-81(2010).
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:20203422}. 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   AlphaFoldDB; P86539; -.
DR   SMR; P86539; -.
DR   Proteomes; UP000694559; Unplaced.
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   Gene3D; 2.10.60.10; -; 1.
DR   InterPro; IPR003572; Cytotoxin_Cobra.
DR   InterPro; IPR045860; Snake_toxin-like_sf.
DR   PRINTS; PR00282; CYTOTOXIN.
DR   SUPFAM; SSF57302; SSF57302; 1.
PE   1: Evidence at protein level;
KW   Cardiotoxin; Cytolysis; Direct protein sequencing; Disulfide bond;
KW   Membrane; Reference proteome; Secreted; Target cell membrane;
KW   Target membrane; Toxin.
FT   CHAIN           1..>30
FT                   /note="Cytotoxin 3a"
FT                   /evidence="ECO:0000269|PubMed:20203422"
FT                   /id="PRO_0000394687"
FT   DISULFID        3..21
FT                   /evidence="ECO:0000250|UniProtKB:P60301"
FT   DISULFID        14..?
FT                   /evidence="ECO:0000250|UniProtKB:P60301"
FT   NON_TER         30
FT                   /evidence="ECO:0000303|PubMed:20203422"
SQ   SEQUENCE   30 AA;  3377 MW;  CDD1E274B17CD30D CRC64;
     LKCNKLIPLA YKTCPAGKNL CYKMYMVATP