ID   MYX3_CROVV              Reviewed;          45 AA.
AC   P63176; P19861;
DT   27-SEP-2004, integrated into UniProtKB/Swiss-Prot.
DT   27-SEP-2004, sequence version 1.
DT   25-MAY-2022, entry version 55.
DE   RecName: Full=Myotoxin-3;
OS   Crotalus viridis viridis (Prairie rattlesnake).
OC   Eukaryota; Metazoa; Chordata; Craniata; Vertebrata; Euteleostomi;
OC   Lepidosauria; Squamata; Bifurcata; Unidentata; Episquamata; Toxicofera;
OC   Serpentes; Colubroidea; Viperidae; Crotalinae; Crotalus.
OX   NCBI_TaxID=8742;
RN   [1]
RP   PROTEIN SEQUENCE, MASS SPECTROMETRY, AND SUBCELLULAR LOCATION.
RC   TISSUE=Venom;
RX   PubMed=2253781; DOI=10.1016/0014-5793(90)81325-i;
RA   Griffin P.R., Aird S.D.;
RT   "A new small myotoxin from the venom of the prairie rattlesnake (Crotalus
RT   viridis viridis).";
RL   FEBS Lett. 274:43-47(1990).
CC   -!- FUNCTION: Cationic peptide that possesses multiple functions. It acts
CC       as a cell-penetrating peptide (CPP), and as a potent voltage-gated
CC       potassium channel (Kv) inhibitor. It exhibits antimicrobial activities,
CC       hind limb paralysis, and severe muscle necrosis by a non-enzymatic
CC       mechanism. {ECO:0000250|UniProtKB:Q9PWF3}.
CC   -!- SUBUNIT: Monomer. {ECO:0000250}.
CC   -!- SUBCELLULAR LOCATION: Secreted {ECO:0000269|PubMed:2253781}.
CC   -!- TISSUE SPECIFICITY: Expressed by the venom gland.
CC       {ECO:0000305|PubMed:2253781}.
CC   -!- MASS SPECTROMETRY: Mass=5168.9; Mass_error=1.55; Method=FAB;
CC       Evidence={ECO:0000269|PubMed:2253781};
CC   -!- SIMILARITY: Belongs to the crotamine-myotoxin family. {ECO:0000305}.
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DR   PIR; S12909; S12909.
DR   AlphaFoldDB; P63176; -.
DR   SMR; P63176; -.
DR   GO; GO:0005576; C:extracellular region; IEA:UniProtKB-SubCell.
DR   GO; GO:0015459; F:potassium channel regulator activity; IEA:UniProtKB-KW.
DR   GO; GO:0090729; F:toxin activity; IEA:UniProtKB-KW.
DR   GO; GO:0044564; P:envenomation resulting in occlusion of the pore of voltage-gated potassium channel in another organism; ISS:UniProtKB.
DR   Gene3D; 2.20.20.10; -; 1.
DR   InterPro; IPR023355; Myo_ane_neurotoxin_sf.
DR   InterPro; IPR000881; Myotoxin.
DR   Pfam; PF00819; Myotoxins; 1.
DR   PRINTS; PR00283; MYOTOXIN.
DR   PROSITE; PS00459; MYOTOXINS_1; 1.
DR   PROSITE; PS51345; MYOTOXINS_2; 1.
PE   1: Evidence at protein level;
KW   Antimicrobial; Direct protein sequencing; Disulfide bond;
KW   Ion channel impairing toxin; Myotoxin; Neurotoxin;
KW   Potassium channel impairing toxin; Secreted; Toxin;
KW   Voltage-gated potassium channel impairing toxin.
FT   CHAIN           1..45
FT                   /note="Myotoxin-3"
FT                   /evidence="ECO:0000269|PubMed:2253781"
FT                   /id="PRO_0000221567"
FT   DISULFID        4..36
FT                   /evidence="ECO:0000250|UniProtKB:Q9PWF3"
FT   DISULFID        11..30
FT                   /evidence="ECO:0000250|UniProtKB:Q9PWF3"
FT   DISULFID        18..37
FT                   /evidence="ECO:0000250|UniProtKB:Q9PWF3"
SQ   SEQUENCE   45 AA;  5174 MW;  8A12DD3B5D98DF3A CRC64;
     YKRCHKKGGH CFPKTVICLP PSSDFGKMDC RWKWKCCKKG SVNNA