ID   STXB_SHIDS              Reviewed;          89 AA.
AC   Q32GM0;
DT   04-DEC-2007, integrated into UniProtKB/Swiss-Prot.
DT   06-DEC-2005, sequence version 1.
DT   25-MAY-2022, entry version 76.
DE   RecName: Full=Shiga toxin subunit B;
DE   Flags: Precursor;
GN   Name=stxB; OrderedLocusNames=SDY_1390;
OS   Shigella dysenteriae serotype 1 (strain Sd197).
OC   Bacteria; Proteobacteria; Gammaproteobacteria; Enterobacterales;
OC   Enterobacteriaceae; Shigella.
OX   NCBI_TaxID=300267;
RN   [1]
RP   NUCLEOTIDE SEQUENCE [LARGE SCALE GENOMIC DNA].
RC   STRAIN=Sd197;
RX   PubMed=16275786; DOI=10.1093/nar/gki954;
RA   Yang F., Yang J., Zhang X., Chen L., Jiang Y., Yan Y., Tang X., Wang J.,
RA   Xiong Z., Dong J., Xue Y., Zhu Y., Xu X., Sun L., Chen S., Nie H., Peng J.,
RA   Xu J., Wang Y., Yuan Z., Wen Y., Yao Z., Shen Y., Qiang B., Hou Y., Yu J.,
RA   Jin Q.;
RT   "Genome dynamics and diversity of Shigella species, the etiologic agents of
RT   bacillary dysentery.";
RL   Nucleic Acids Res. 33:6445-6458(2005).
CC   -!- FUNCTION: The B subunit is responsible for the binding of the holotoxin
CC       to specific receptors on the target cell surface, such as
CC       globotriaosylceramide (Gb3) in human intestinal microvilli.
CC       {ECO:0000250}.
CC   -!- SUBUNIT: Shiga toxin contains a single subunit A and five copies of
CC       subunit B. {ECO:0000250}.
CC   -!- DOMAIN: There are three Gb3-binding sites in each subunit B monomer,
CC       allowing for a tighter binding to the target cell. Binding sites 1 and
CC       2 have higher binding affinities than site 3 (By similarity).
CC       {ECO:0000250}.
CC   -!- SIMILARITY: Belongs to the StxB family. {ECO:0000305}.
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DR   EMBL; CP000034; ABB61535.1; -; Genomic_DNA.
DR   RefSeq; WP_000752026.1; NC_007606.1.
DR   RefSeq; YP_403026.1; NC_007606.1.
DR   AlphaFoldDB; Q32GM0; -.
DR   SMR; Q32GM0; -.
DR   EnsemblBacteria; ABB61535; ABB61535; SDY_1390.
DR   KEGG; sdy:SDY_1390; -.
DR   PATRIC; fig|300267.13.peg.1651; -.
DR   HOGENOM; CLU_191376_0_0_6; -.
DR   Proteomes; UP000002716; Chromosome.
DR   GO; GO:0005576; C:extracellular region; IEA:InterPro.
DR   GO; GO:0044177; C:host cell Golgi apparatus; IDA:UniProtKB.
DR   GO; GO:0090729; F:toxin activity; IEA:UniProtKB-KW.
DR   GO; GO:0019836; P:hemolysis by symbiont of host erythrocytes; IEA:InterPro.
DR   InterPro; IPR008992; Enterotoxin.
DR   InterPro; IPR003189; SLT_beta.
DR   Pfam; PF02258; SLT_beta; 1.
DR   SUPFAM; SSF50203; SSF50203; 1.
PE   3: Inferred from homology;
KW   Disulfide bond; Reference proteome; Signal; Toxin; Virulence.
FT   SIGNAL          1..20
FT                   /evidence="ECO:0000255"
FT   CHAIN           21..89
FT                   /note="Shiga toxin subunit B"
FT                   /id="PRO_0000312306"
FT   DISULFID        24..77
FT                   /evidence="ECO:0000250"
SQ   SEQUENCE   89 AA;  9743 MW;  C78F7795CCD7242E CRC64;
     MKKTLLIAAS LSFFSASALA TPDCVTGKVE YTKYNDDDTF TVKVGDKELF TNRWNLQSLL
     LSAQITGMTV TIKTNACHNG GGFSEVIFR