ID   3S1B2_NAJKA             Reviewed;          62 AA.
AC   P82849;
DT   04-MAY-2001, integrated into UniProtKB/Swiss-Prot.
DT   01-MAR-2001, sequence version 1.
DT   25-MAY-2022, entry version 87.
DE   RecName: Full=Cobrotoxin II;
DE            Short=CBT II;
DE   AltName: Full=CBT2;
DE   AltName: Full=Short neurotoxin 1;
DE   AltName: Full=Short neurotoxin 5;
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, STRUCTURE BY NMR, DISULFIDE BONDS, AND SUBCELLULAR
RP   LOCATION.
RC   TISSUE=Venom;
RA   Cheng Y., Wang W., Wang J.;
RL   Submitted (NOV-2000) to UniProtKB.
CC   -!- FUNCTION: Binds to muscle nicotinic acetylcholine receptor (nAChR) and
CC       inhibit acetylcholine from binding to the receptor, thereby impairing
CC       neuromuscular transmission. {ECO:0000250|UniProtKB:P60775}.
CC   -!- SUBCELLULAR LOCATION: Secreted {ECO:0000269|Ref.1}.
CC   -!- TISSUE SPECIFICITY: Expressed by the venom gland. {ECO:0000305}.
CC   -!- SIMILARITY: Belongs to the snake three-finger toxin family. Short-chain
CC       subfamily. Type I alpha-neurotoxin sub-subfamily. {ECO:0000305}.
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DR   PDB; 1G6M; NMR; -; A=1-62.
DR   PDBsum; 1G6M; -.
DR   AlphaFoldDB; P82849; -.
DR   SMR; P82849; -.
DR   EvolutionaryTrace; P82849; -.
DR   GO; GO:0005576; C:extracellular region; IEA:UniProtKB-SubCell.
DR   GO; GO:0030550; F:acetylcholine receptor inhibitor activity; IEA:UniProtKB-KW.
DR   GO; GO:0099106; F:ion channel regulator activity; IEA:UniProtKB-KW.
DR   GO; GO:0090729; F:toxin activity; IEA:UniProtKB-KW.
DR   CDD; cd00206; snake_toxin; 1.
DR   Gene3D; 2.10.60.10; -; 1.
DR   InterPro; IPR003571; Snake_3FTx.
DR   InterPro; IPR045860; Snake_toxin-like_sf.
DR   InterPro; IPR018354; Snake_toxin_con_site.
DR   SUPFAM; SSF57302; SSF57302; 1.
DR   PROSITE; PS00272; SNAKE_TOXIN; 1.
PE   1: Evidence at protein level;
KW   3D-structure; Acetylcholine receptor inhibiting toxin;
KW   Direct protein sequencing; Disulfide bond; Ion channel impairing toxin;
KW   Neurotoxin; Postsynaptic neurotoxin; Secreted; Toxin.
FT   CHAIN           1..62
FT                   /note="Cobrotoxin II"
FT                   /evidence="ECO:0000269|Ref.1"
FT                   /id="PRO_0000093614"
FT   REGION          1..23
FT                   /note="Disordered"
FT                   /evidence="ECO:0000256|SAM:MobiDB-lite"
FT   COMPBIAS        1..21
FT                   /note="Polar residues"
FT                   /evidence="ECO:0000256|SAM:MobiDB-lite"
FT   DISULFID        3..24
FT                   /evidence="ECO:0000269|Ref.1, ECO:0000312|PDB:1G6M"
FT   DISULFID        17..41
FT                   /evidence="ECO:0000269|Ref.1, ECO:0000312|PDB:1G6M"
FT   DISULFID        43..54
FT                   /evidence="ECO:0000269|Ref.1, ECO:0000312|PDB:1G6M"
FT   DISULFID        55..60
FT                   /evidence="ECO:0000269|Ref.1, ECO:0000312|PDB:1G6M"
FT   STRAND          2..4
FT                   /evidence="ECO:0007829|PDB:1G6M"
FT   STRAND          14..16
FT                   /evidence="ECO:0007829|PDB:1G6M"
FT   STRAND          24..30
FT                   /evidence="ECO:0007829|PDB:1G6M"
FT   STRAND          35..39
FT                   /evidence="ECO:0007829|PDB:1G6M"
FT   STRAND          49..51
FT                   /evidence="ECO:0007829|PDB:1G6M"
SQ   SEQUENCE   62 AA;  6862 MW;  3511B09D2F1236E9 CRC64;
     LECHNQQSSQ TPTTTGCSGG ENNCYKKEWR DNRGYRTERG CGCPSVKKGI GINCCTTDRC
     NN