ID   TACB1_TACTR             Reviewed;          42 AA.
AC   P0C1Z8;
DT   31-OCT-2006, integrated into UniProtKB/Swiss-Prot.
DT   31-OCT-2006, sequence version 1.
DT   25-MAY-2022, entry version 41.
DE   RecName: Full=Tachystatin-B1;
OS   Tachypleus tridentatus (Japanese horseshoe crab).
OC   Eukaryota; Metazoa; Ecdysozoa; Arthropoda; Chelicerata; Merostomata;
OC   Xiphosura; Limulidae; Tachypleus.
OX   NCBI_TaxID=6853;
RN   [1]
RP   PROTEIN SEQUENCE, AND TISSUE SPECIFICITY.
RX   PubMed=10473569; DOI=10.1074/jbc.274.37.26172;
RA   Osaki T., Omotezako M., Nagayama R., Hirata M., Iwanaga S., Kasahara J.,
RA   Hattori J., Ito I., Sugiyama H., Kawabata S.;
RT   "Horseshoe crab hemocyte-derived antimicrobial polypeptides, tachystatins,
RT   with sequence similarity to spider neurotoxins.";
RL   J. Biol. Chem. 274:26172-26178(1999).
RN   [2]
RP   STRUCTURE BY NMR, AND DISULFIDE BONDS.
RX   PubMed=17394123; DOI=10.1002/psc.846;
RA   Fujitani N., Kouno T., Nakahara T., Takaya K., Osaki T., Kawabata S.,
RA   Mizuguchi M., Aizawa T., Demura M., Nishimura S., Kawano K.;
RT   "The solution structure of horseshoe crab antimicrobial peptide tachystatin
RT   B with an inhibitory cystine-knot motif.";
RL   J. Pept. Sci. 13:269-279(2007).
CC   -!- FUNCTION: Exhibits stronger antimicrobial activity against the Gram-
CC       positive bacteria (S.aureus (IC(50) is 7.4 ug/ml)) and fungi
CC       (C.albicans (IC(50) is 3.0 ug/ml) and P.pastoris (IC(50) is 0.1 ug/ml))
CC       than Gram-negative bacteria (E.coli no inhibition at 100 ug/ml). Binds
CC       to chitin (4.3 uM are required to obtain 50% of binding). Does not
CC       cause hemolysis on sheep erythrocytes. Has no blocking activity on the
CC       P-type calcium channel.
CC   -!- SUBCELLULAR LOCATION: Secreted.
CC   -!- TISSUE SPECIFICITY: Granular hemocytes, small secretory granules.
CC       {ECO:0000269|PubMed:10473569}.
CC   -!- DOMAIN: The presence of a 'disulfide through disulfide knot'
CC       structurally defines this protein as a knottin.
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DR   PDB; 2DCV; NMR; -; A=1-42.
DR   PDBsum; 2DCV; -.
DR   AlphaFoldDB; P0C1Z8; -.
DR   BMRB; P0C1Z8; -.
DR   SMR; P0C1Z8; -.
DR   TCDB; 8.B.6.1.8; the ca(2+) channel-targeting spider toxin (cst) family.
DR   EvolutionaryTrace; P0C1Z8; -.
DR   GO; GO:0005576; C:extracellular region; IEA:UniProtKB-SubCell.
DR   GO; GO:0042742; P:defense response to bacterium; IEA:UniProtKB-KW.
DR   GO; GO:0050832; P:defense response to fungus; IEA:UniProtKB-KW.
DR   GO; GO:0031640; P:killing of cells of another organism; IEA:UniProtKB-KW.
DR   InterPro; IPR020957; Tachystatin_B.
DR   Pfam; PF11478; Tachystatin_B; 1.
PE   1: Evidence at protein level;
KW   3D-structure; Antibiotic; Antimicrobial; Direct protein sequencing;
KW   Disulfide bond; Fungicide; Knottin; Secreted.
FT   PEPTIDE         1..42
FT                   /note="Tachystatin-B1"
FT                   /id="PRO_0000256691"
FT   DISULFID        4..20
FT                   /evidence="ECO:0000269|PubMed:17394123"
FT   DISULFID        11..25
FT                   /evidence="ECO:0000269|PubMed:17394123"
FT   DISULFID        19..37
FT                   /evidence="ECO:0000269|PubMed:17394123"
FT   STRAND          10..12
FT                   /evidence="ECO:0007829|PDB:2DCV"
FT   STRAND          23..29
FT                   /evidence="ECO:0007829|PDB:2DCV"
FT   STRAND          33..39
FT                   /evidence="ECO:0007829|PDB:2DCV"
SQ   SEQUENCE   42 AA;  4919 MW;  DCFDD576C77C3AF0 CRC64;
     YVSCLFRGAR CRVYSGRSCC FGYYCRRDFP GSIFGTCSRR NF