SFI8_SEGFL
ID SFI8_SEGFL Reviewed; 46 AA.
AC P61102;
DT 26-APR-2004, integrated into UniProtKB/Swiss-Prot.
DT 26-APR-2004, sequence version 1.
DT 25-MAY-2022, entry version 36.
DE RecName: Full=Mu-segestritoxin-Sf1h {ECO:0000305};
DE Short=Mu-SGTX-Sf1h {ECO:0000305};
DE AltName: Full=Toxin SFI8 {ECO:0000303|PubMed:11689233};
OS Segestria florentina (Tube-web spider) (Segestria gracilis).
OC Eukaryota; Metazoa; Ecdysozoa; Arthropoda; Chelicerata; Arachnida; Araneae;
OC Araneomorphae; Haplogynae; Dysderoidea; Segestriidae; Segestria.
OX NCBI_TaxID=31925;
RN [1]
RP NUCLEOTIDE SEQUENCE [MRNA].
RC TISSUE=Venom gland;
RX PubMed=11689233; DOI=10.1016/s0041-0101(01)00181-7;
RA Lipkin A., Kozlov S., Nosyreva E., Blake A., Windass J.D., Grishin E.;
RT "Novel insecticidal toxins from the venom of the spider Segestria
RT florentina.";
RL Toxicon 40:125-130(2002).
CC -!- FUNCTION: Insecticidal toxin. It inhibits insect voltage-gated sodium
CC channels (Nav) by partially blocking the channel pore in DUM neurons
CC from the American cockroach, not by acting as a gating modifier. The
CC inhibition is only partially reversible after prolonged washout. In
CC vivo, the toxin causes flaccid paralysis followed by death when
CC injected into Heliothis virescens larvae. It also causes uncoordinated
CC movements followed by full paralysis to sheep blowflies (Lucilia
CC cuprina). When the toxin is fused to snowdrop lectin, it is orally
CC active against larvae of the tomato moth (Laconobia oleracea), the rice
CC brown planthopper (Nilaparvata lugens), and the peach-potato aphid
CC (Myzus persicae). {ECO:0000250|UniProtKB:P61095}.
CC -!- SUBCELLULAR LOCATION: Secreted {ECO:0000250|UniProtKB:P61095}.
CC -!- TISSUE SPECIFICITY: Expressed by the venom gland.
CC {ECO:0000305|PubMed:11689233}.
CC -!- DOMAIN: The presence of a 'disulfide through disulfide knot'
CC structurally defines this protein as a knottin.
CC {ECO:0000250|UniProtKB:P61095}.
CC -!- SIMILARITY: Belongs to the neurotoxin 16 (SFI) family. {ECO:0000305}.
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DR AlphaFoldDB; P61102; -.
DR SMR; P61102; -.
DR ArachnoServer; AS000123; mu-segestritoxin-Sf1h.
DR GO; GO:0005576; C:extracellular region; IEA:UniProtKB-SubCell.
DR GO; GO:0090729; F:toxin activity; IEA:UniProtKB-KW.
DR InterPro; IPR012633; Toxin_28.
DR Pfam; PF08115; Toxin_28; 1.
PE 3: Inferred from homology;
KW Disulfide bond; Knottin; Secreted; Toxin.
FT CHAIN 1..46
FT /note="Mu-segestritoxin-Sf1h"
FT /evidence="ECO:0000305|PubMed:11689233"
FT /id="PRO_0000087623"
FT REGION 31..33
FT /note="Keys region for toxin activity"
FT /evidence="ECO:0000250|UniProtKB:P61095"
FT DISULFID 3..19
FT /evidence="ECO:0000250|UniProtKB:P61095"
FT DISULFID 10..22
FT /evidence="ECO:0000250|UniProtKB:P61095"
FT DISULFID 18..42
FT /evidence="ECO:0000250|UniProtKB:P61095"
FT DISULFID 24..40
FT /evidence="ECO:0000250|UniProtKB:P61095"
SQ SEQUENCE 46 AA; 4941 MW; BFADFDDF628C791F CRC64;
KECMADGTVC YIHNHNDCCG SCLCPNGPLA RPWEMLVGNC KCGPKA