ID   LTX1B_LACTA             Reviewed;          86 AA.
AC   B3EWF3; K7XJP8;
DT   03-APR-2013, integrated into UniProtKB/Swiss-Prot.
DT   03-APR-2013, sequence version 1.
DT   25-MAY-2022, entry version 19.
DE   RecName: Full=Latartoxin-1b {ECO:0000303|PubMed:23088912};
DE            Short=LtTx-1b {ECO:0000303|PubMed:23088912};
DE   Flags: Precursor;
OS   Lachesana tarabaevi (Spider).
OC   Eukaryota; Metazoa; Ecdysozoa; Arthropoda; Chelicerata; Arachnida; Araneae;
OC   Araneomorphae; Entelegynae; Entelegynae incertae sedis; Zodariidae;
OC   Lachesana.
OX   NCBI_TaxID=379576;
RN   [1]
RP   NUCLEOTIDE SEQUENCE [MRNA], PROTEIN SEQUENCE OF 27-86, FUNCTION,
RP   SUBCELLULAR LOCATION, DISULFIDE BONDS, MASS SPECTROMETRY, AND TOXIC DOSE.
RC   TISSUE=Venom, and Venom gland;
RX   PubMed=23088912; DOI=10.1016/j.bbamem.2012.10.014;
RA   Kuzmenkov A.I., Fedorova I.M., Vassilevski A.A., Grishin E.V.;
RT   "Cysteine-rich toxins from Lachesana tarabaevi spider venom with
RT   amphiphilic C-terminal segments.";
RL   Biochim. Biophys. Acta 1828:724-731(2013).
RN   [2]
RP   SUBCELLULAR LOCATION, PQM MOTIF, AND MASS SPECTROMETRY.
RC   TISSUE=Venom;
RX   PubMed=27287558; DOI=10.1042/bcj20160436;
RA   Kuzmenkov A.I., Sachkova M.Y., Kovalchuk S.I., Grishin E.V.,
RA   Vassilevski A.A.;
RT   "Lachesana tarabaevi, an expert in membrane-active toxins.";
RL   Biochem. J. 473:2495-2506(2016).
CC   -!- FUNCTION: Insect toxin. {ECO:0000269|PubMed:23088912}.
CC   -!- SUBCELLULAR LOCATION: Secreted {ECO:0000269|PubMed:23088912,
CC       ECO:0000269|PubMed:27287558}.
CC   -!- TISSUE SPECIFICITY: Expressed by the venom gland.
CC       {ECO:0000305|PubMed:23088912}.
CC   -!- DOMAIN: The presence of a 'disulfide through disulfide knot'
CC       structurally defines this protein as a knottin. {ECO:0000305}.
CC   -!- DOMAIN: The C-terminal part (65-85) forms an alpha-helix which probably
CC       disrupts target membranes. {ECO:0000250|UniProtKB:B3EWF2}.
CC   -!- PTM: Contains 4 disulfide bonds. {ECO:0000269|PubMed:23088912}.
CC   -!- PTM: Cleavage of the propeptide depends on the processing quadruplet
CC       motif (XXXR, with at least one of X being E).
CC       {ECO:0000303|PubMed:27287558}.
CC   -!- MASS SPECTROMETRY: Mass=6790.7; Mass_error=0.5; Method=MALDI;
CC       Evidence={ECO:0000269|PubMed:23088912};
CC   -!- MASS SPECTROMETRY: Mass=6791.4; Method=MALDI;
CC       Evidence={ECO:0000269|PubMed:27287558};
CC   -!- TOXIC DOSE: LD(50) is 45 ug/g in flesh fly larvae (S.carnaria).
CC       {ECO:0000269|PubMed:23088912}.
CC   -!- TOXIC DOSE: LD(50) is 45 ug/g in house crickets (Acheta domesticus).
CC       {ECO:0000269|PubMed:23088912}.
CC   -!- SIMILARITY: Belongs to the neurotoxin 19 (CSTX) family. {ECO:0000255}.
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DR   EMBL; JQ513643; AFX65328.1; -; mRNA.
DR   AlphaFoldDB; B3EWF3; -.
DR   SMR; B3EWF3; -.
DR   TCDB; 8.B.19.2.5; the sea anemone k+ channel blocker toxin, bcstx3 (bcstx3) family.
DR   ArachnoServer; AS001850; U1-zodatoxin-Lt1b.
DR   GO; GO:0005576; C:extracellular region; IEA:UniProtKB-SubCell.
DR   GO; GO:0090729; F:toxin activity; IEA:UniProtKB-KW.
DR   InterPro; IPR019553; Spider_toxin_CSTX_knottin.
DR   Pfam; PF10530; Toxin_35; 1.
PE   1: Evidence at protein level;
KW   Direct protein sequencing; Disulfide bond; Knottin; Secreted; Signal;
KW   Toxin.
FT   SIGNAL          1..19
FT                   /evidence="ECO:0000255"
FT   PROPEP          20..26
FT                   /note="Removed in mature form"
FT                   /evidence="ECO:0000269|PubMed:23088912"
FT                   /id="PRO_0000421843"
FT   PEPTIDE         27..86
FT                   /note="Latartoxin-1b"
FT                   /id="PRO_0000421844"
FT   MOTIF           23..26
FT                   /note="Processing quadruplet motif"
FT                   /evidence="ECO:0000303|PubMed:27287558"
FT   DISULFID        28..43
FT                   /evidence="ECO:0000250|UniProtKB:P58604"
FT   DISULFID        35..48
FT                   /evidence="ECO:0000250|UniProtKB:P58604"
FT   DISULFID        42..65
FT                   /evidence="ECO:0000250|UniProtKB:P58604"
FT   DISULFID        50..63
FT                   /evidence="ECO:0000250|UniProtKB:P58604"
SQ   SEQUENCE   86 AA;  9581 MW;  590FD844FBA13379 CRC64;
     MKILVLAVVC TVLLQVALSA DSEEVRDCIP TRHECTNNQQ NCCEGHDCKC DYTEIGGAKK
     EICYCKKTLW QKTKDKLSTA GDILKS