ID   MYXC_CROOH              Reviewed;          70 AA.
AC   P01477; G9DCI6;
DT   21-JUL-1986, integrated into UniProtKB/Swiss-Prot.
DT   13-NOV-2013, sequence version 2.
DT   25-MAY-2022, entry version 83.
DE   RecName: Full=Myotoxin;
DE   AltName: Full=Crotamine-4;
DE   AltName: Full=Toxic peptide C;
DE   Flags: Precursor;
OS   Crotalus oreganus helleri (Southern pacific rattlesnake) (Crotalus viridis
OS   helleri).
OC   Eukaryota; Metazoa; Chordata; Craniata; Vertebrata; Euteleostomi;
OC   Lepidosauria; Squamata; Bifurcata; Unidentata; Episquamata; Toxicofera;
OC   Serpentes; Colubroidea; Viperidae; Crotalinae; Crotalus.
OX   NCBI_TaxID=8741;
RN   [1]
RP   NUCLEOTIDE SEQUENCE [MRNA].
RC   TISSUE=Venom gland;
RA   Sanchez E.;
RT   "cDNA clones from the library of Crotalus oreganus helleri (Southern
RT   Pacific Rattlesnake) venom gland.";
RL   Submitted (APR-2011) to the EMBL/GenBank/DDBJ databases.
RN   [2]
RP   NUCLEOTIDE SEQUENCE [MRNA].
RC   TISSUE=Venom gland;
RA   Fry B.G.;
RT   "Clinical and biodiscovery implications of intra-specific venom variation
RT   in the medically important Southern Pacific Rattlesnake (Crotalus oreganus
RT   helleri).";
RL   Submitted (JUL-2013) to the EMBL/GenBank/DDBJ databases.
RN   [3]
RP   PROTEIN SEQUENCE OF 23-65, TOXIC DOSE, AND SUBCELLULAR LOCATION.
RC   TISSUE=Venom;
RX   PubMed=694946; DOI=10.1016/0041-0101(78)90140-x;
RA   Maeda N., Tamiya N., Pattabhiraman T.R., Russell F.E.;
RT   "Some chemical properties of the venom of the rattlesnake, Crotalus viridis
RT   helleri.";
RL   Toxicon 16:431-441(1978).
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 (By similarity). {ECO:0000250|UniProtKB:Q9PWF3}.
CC   -!- SUBUNIT: Monomer. {ECO:0000250}.
CC   -!- SUBCELLULAR LOCATION: Secreted {ECO:0000269|PubMed:694946}.
CC   -!- TISSUE SPECIFICITY: Expressed by the venom gland.
CC       {ECO:0000305|PubMed:694946}.
CC   -!- TOXIC DOSE: LD(50) is 1.96 mg/kg by intravenous injection.
CC       {ECO:0000269|PubMed:694946}.
CC   -!- SIMILARITY: Belongs to the crotamine-myotoxin family. {ECO:0000305}.
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DR   EMBL; JF895769; AEU60012.1; -; mRNA.
DR   EMBL; GAKQ01000002; JAA97967.1; -; mRNA.
DR   EMBL; GAKQ01000001; JAA97968.1; -; mRNA.
DR   EMBL; GAKR01000001; JAA97984.1; -; mRNA.
DR   EMBL; GAKS01000002; JAA98014.1; -; mRNA.
DR   EMBL; GAKS01000001; JAA98015.1; -; mRNA.
DR   EMBL; GALC01000001; JAA98041.1; -; mRNA.
DR   PIR; A01737; CXRSCH.
DR   AlphaFoldDB; P01477; -.
DR   SMR; P01477; -.
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; Signal; Toxin;
KW   Voltage-gated potassium channel impairing toxin.
FT   SIGNAL          1..22
FT                   /evidence="ECO:0000269|PubMed:694946"
FT   CHAIN           23..70
FT                   /note="Myotoxin"
FT                   /evidence="ECO:0000305|PubMed:694946"
FT                   /id="PRO_0000221569"
FT   DISULFID        26..58
FT                   /evidence="ECO:0000250|UniProtKB:Q9PWF3"
FT   DISULFID        33..52
FT                   /evidence="ECO:0000250|UniProtKB:Q9PWF3"
FT   DISULFID        40..59
FT                   /evidence="ECO:0000250|UniProtKB:Q9PWF3"
SQ   SEQUENCE   70 AA;  7989 MW;  06B32AE06B0989F1 CRC64;
     MKILYLLFAF LFLAFLSEPG NAYKRCHKKG GHCFPKTVIC LPPSSDFGKM DCRWKWKCCK
     KGSVNNAISI