STXB_BPH19
ID STXB_BPH19 Reviewed; 89 AA.
AC P69179; P08027;
DT 01-AUG-1988, integrated into UniProtKB/Swiss-Prot.
DT 01-AUG-1988, sequence version 1.
DT 03-AUG-2022, entry version 73.
DE RecName: Full=Shiga-like toxin 1 subunit B;
DE Short=SLT-1 B subunit;
DE Short=SLT-1b;
DE Short=SLT-Ib;
DE AltName: Full=Verocytotoxin 1 subunit B;
DE Short=Verotoxin 1 subunit B;
DE Flags: Precursor;
GN Name=stxB; Synonyms=sltB;
OS Enterobacteria phage H19B (Bacteriophage H19B).
OC Viruses; Duplodnaviria; Heunggongvirae; Uroviricota; Caudoviricetes;
OC Caudovirales; Siphoviridae; Lambdavirus; unclassified Lambdavirus.
OX NCBI_TaxID=69932;
OH NCBI_TaxID=562; Escherichia coli.
RN [1]
RP NUCLEOTIDE SEQUENCE [GENOMIC DNA].
RX PubMed=3299365; DOI=10.1073/pnas.84.13.4364;
RA Calderwood S.B., Auclair F., Donohue-Rolfe A., Keusch G.T., Mekalanos J.J.;
RT "Nucleotide sequence of the Shiga-like toxin genes of Escherichia coli.";
RL Proc. Natl. Acad. Sci. U.S.A. 84:4364-4368(1987).
RN [2]
RP NUCLEOTIDE SEQUENCE [GENOMIC DNA].
RX PubMed=3040689; DOI=10.1128/jb.169.9.4313-4319.1987;
RA de Grandis S., Ginsberg J., Toone M., Climie S., Friesen J., Brunton J.L.;
RT "Nucleotide sequence and promoter mapping of the Escherichia coli Shiga-
RT like toxin operon of bacteriophage H-19B.";
RL J. Bacteriol. 169:4313-4319(1987).
RN [3]
RP MUTAGENESIS OF LYS-33; ASP-37; PHE-50 AND GLU-85.
RX PubMed=8820657; DOI=10.1046/j.1365-2958.1996.427962.x;
RA Clark C., Bast D.J., Sharp A.M., St Hilaire P.M., Agha R., Stein P.E.,
RA Toone E.J., Read R.J., Brunton J.L.;
RT "Phenylalanine 30 plays an important role in receptor binding of verotoxin-
RT 1.";
RL Mol. Microbiol. 19:891-899(1996).
RN [4]
RP MUTAGENESIS OF ASP-37; TRP-54 AND GLY-82.
RX PubMed=10361298; DOI=10.1046/j.1365-2958.1999.01405.x;
RA Bast D.J., Banerjee L., Clark C., Read R.J., Brunton J.L.;
RT "The identification of three biologically relevant globotriaosyl ceramide
RT receptor binding sites on the Verotoxin 1 B subunit.";
RL Mol. Microbiol. 32:953-960(1999).
RN [5]
RP X-RAY CRYSTALLOGRAPHY (2.2 ANGSTROMS) OF 21-89.
RX PubMed=1741063; DOI=10.1038/355748a0;
RA Stein P.E., Boodhoo A., Tyrrell G.J., Brunton J.L., Read R.J.;
RT "Crystal structure of the cell-binding B oligomer of verotoxin-1 from E.
RT coli.";
RL Nature 355:748-750(1992).
RN [6]
RP STRUCTURE BY NMR OF 21-89.
RX PubMed=9164458; DOI=10.1038/nsb0397-190;
RA Richardson J.M., Evans P.D., Homans S.W., Donohue-Rolfe A.;
RT "Solution structure of the carbohydrate-binding B-subunit homopentamer of
RT verotoxin VT-1 from E. coli.";
RL Nat. Struct. Biol. 4:190-193(1997).
RN [7]
RP X-RAY CRYSTALLOGRAPHY (2.8 ANGSTROMS) OF 21-89 IN COMPLEX WITH RECEPTOR
RP GB3.
RX PubMed=9485303; DOI=10.1021/bi971806n;
RA Ling H., Boodhoo A., Hazes B., Cummings M.D., Armstrong G.D., Brunton J.L.,
RA Read R.J.;
RT "Structure of the shiga-like toxin I B-pentamer complexed with an analogue
RT of its receptor Gb3.";
RL Biochemistry 37:1777-1788(1998).
RN [8]
RP X-RAY CRYSTALLOGRAPHY (2.23 ANGSTROMS) OF 21-89 IN COMPLEX WITH INHIBITOR.
RX PubMed=10688205; DOI=10.1038/35001095;
RA Kitov P.I., Sadowska J.M., Mulvey G., Armstrong G.D., Ling H., Pannu N.S.,
RA Read R.J., Bundle D.R.;
RT "Shiga-like toxins are neutralized by tailored multivalent carbohydrate
RT ligands.";
RL Nature 403:669-672(2000).
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 -!- SUBUNIT: Shiga-like toxin contains a single subunit A and five copies
CC of subunit B. {ECO:0000269|PubMed:10688205,
CC ECO:0000269|PubMed:9485303}.
CC -!- SUBCELLULAR LOCATION: Secreted.
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.
CC -!- SIMILARITY: Belongs to the stxB family. {ECO:0000305}.
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DR EMBL; M16625; AAA98100.1; -; Genomic_DNA.
DR EMBL; M17358; AAA32230.1; -; Genomic_DNA.
DR PIR; B27052; XVBPH9.
DR PIR; B53887; B53887.
DR PDB; 1BOS; X-ray; 2.80 A; A/B/C/D/E/F/G/H/I/J/K/L/M/N/O/P/Q/R/S/T=21-89.
DR PDB; 1C48; X-ray; 1.60 A; A/B/C/D/E=21-89.
DR PDB; 1C4Q; X-ray; 1.52 A; A/B/C/D/E=21-89.
DR PDB; 1CQF; X-ray; 2.20 A; A/B/C/D/E=21-89.
DR PDB; 1CZG; X-ray; 2.50 A; A/B/C/D/E=21-89.
DR PDB; 1CZW; X-ray; 2.50 A; A/B/C/D/E/F/G/H/I/J=21-89.
DR PDB; 1D1I; X-ray; 1.70 A; A/B/C/D/E=21-89.
DR PDB; 1QNU; X-ray; 2.23 A; A/B/C/D/E=21-89.
DR PDB; 2XSC; X-ray; 2.05 A; A/B/C/D/E=21-89.
DR PDB; 4ULL; NMR; -; A=21-89.
DR PDBsum; 1BOS; -.
DR PDBsum; 1C48; -.
DR PDBsum; 1C4Q; -.
DR PDBsum; 1CQF; -.
DR PDBsum; 1CZG; -.
DR PDBsum; 1CZW; -.
DR PDBsum; 1D1I; -.
DR PDBsum; 1QNU; -.
DR PDBsum; 2XSC; -.
DR PDBsum; 4ULL; -.
DR SMR; P69179; -.
DR UniLectin; P69179; -.
DR ABCD; P69179; 2 sequenced antibodies.
DR EvolutionaryTrace; P69179; -.
DR GO; GO:0005576; C:extracellular region; IEA:UniProtKB-SubCell.
DR GO; GO:0090729; F:toxin activity; IEA:UniProtKB-KW.
DR GO; GO:0019836; P:hemolysis by symbiont of host erythrocytes; IEA:InterPro.
DR GO; GO:0098676; P:modulation of host virulence by virus; IEA:UniProtKB-KW.
DR InterPro; IPR008992; Enterotoxin.
DR InterPro; IPR003189; SLT_beta.
DR Pfam; PF02258; SLT_beta; 1.
DR SUPFAM; SSF50203; SSF50203; 1.
PE 1: Evidence at protein level;
KW 3D-structure; Disulfide bond; Modulation of host virulence by virus;
KW Secreted; Signal; Toxin; Viral exotoxin; Virulence.
FT SIGNAL 1..20
FT CHAIN 21..89
FT /note="Shiga-like toxin 1 subunit B"
FT /id="PRO_0000030794"
FT DISULFID 24..77
FT MUTAGEN 33
FT /note="K->A: No effect on binding to receptor."
FT /evidence="ECO:0000269|PubMed:8820657"
FT MUTAGEN 37
FT /note="D->A: No effect on binding to receptor."
FT /evidence="ECO:0000269|PubMed:10361298,
FT ECO:0000269|PubMed:8820657"
FT MUTAGEN 37
FT /note="D->E: Decrease in binding affinity for Gb3, and in
FT binding capacity. Reduced cytotoxicity."
FT /evidence="ECO:0000269|PubMed:10361298,
FT ECO:0000269|PubMed:8820657"
FT MUTAGEN 50
FT /note="F->A: 4-fold decrease in binding affinity for Gb3;
FT 10-fold reduction in binding capacity; great decrease in
FT cell cytotoxicity."
FT /evidence="ECO:0000269|PubMed:8820657"
FT MUTAGEN 54
FT /note="W->A: Decrease in binding capacity; no effect on
FT binding affinity; moderate effect on cytotoxicity."
FT /evidence="ECO:0000269|PubMed:10361298"
FT MUTAGEN 82
FT /note="G->T: Decrease in binding affinity for Gb3, and in
FT binding capacity. Reduced cytotoxicity."
FT /evidence="ECO:0000269|PubMed:10361298"
FT MUTAGEN 85
FT /note="E->A: No effect on binding to receptor."
FT /evidence="ECO:0000269|PubMed:8820657"
FT STRAND 23..34
FT /evidence="ECO:0007829|PDB:1C4Q"
FT STRAND 36..38
FT /evidence="ECO:0007829|PDB:4ULL"
FT STRAND 40..44
FT /evidence="ECO:0007829|PDB:1C4Q"
FT STRAND 47..51
FT /evidence="ECO:0007829|PDB:1C4Q"
FT HELIX 56..66
FT /evidence="ECO:0007829|PDB:1C4Q"
FT STRAND 69..73
FT /evidence="ECO:0007829|PDB:1C4Q"
FT STRAND 77..80
FT /evidence="ECO:0007829|PDB:4ULL"
FT STRAND 85..89
FT /evidence="ECO:0007829|PDB:1C4Q"
SQ SEQUENCE 89 AA; 9743 MW; C78F7795CCD7242E CRC64;
MKKTLLIAAS LSFFSASALA TPDCVTGKVE YTKYNDDDTF TVKVGDKELF TNRWNLQSLL
LSAQITGMTV TIKTNACHNG GGFSEVIFR
