Enterotoxin type B

<h2 id="function">Function</h2>
<p>The function of this protein is to facilitate the infection of the <a href="/facts/Host_(biology)/L6mop0kh">host</a> organism. It is a <a href="/facts/Virulence_factor/jw099pff">virulence factor</a> designed to induce <a href="/facts/Pathogenesis/o9kHHK0U">pathogenesis</a>.<a class="footnote-ref" id="fnref:4" href="#fn:4"><sup>4</sup></a> One of the major virulence <a href="/facts/Exotoxins/j18H60P0">exotoxins</a> is the <a href="/facts/Toxic_shock_syndrome/JC3Ixna4">toxic shock syndrome</a> <a href="/facts/Toxin/11oUNk7n">toxin</a> (TSST), which is <a href="/facts/Secreted/VHk9eLAV">secreted</a> by the <a href="/facts/Organism/j8JkL09u">organism</a> upon successful <a href="/facts/Infection/182XrncP">invasion</a>. It causes a major <a href="/facts/Inflammation/Ura86MIy">inflammatory response</a> in the host via <a href="/facts/Superantigen/5bluJljr">superantigenic</a> properties, and is the causative agent of toxic shock syndrome.  It functions as a superantigen through activation of a significant fraction of <a href="/facts/T-cell/5z6PQ9UN">T-cells</a> (up to 20%) by cross-linking <a href="/facts/MHC_class_II/nQ4hkBgW">MHC class II</a> molecules with <a href="/facts/T-cell_receptor/zDqyWyG4">T-cell receptors</a>. TSST is a multisystem illness with several <a href="/facts/Symptoms/BzP6MrTN">symptoms</a> such as high <a href="/facts/Fever/waVxR2Ac">fever</a>, <a href="/facts/Hypotension/BhrdVVRS">hypotension</a>, dizziness, rash and peeling skin.<a class="footnote-ref" id="fnref:5" href="#fn:5"><sup>5</sup></a>
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<h2 id="structure">Structure</h2>
<p>All of these toxins share a similar two-domain fold (N and C-terminal domains) with a long alpha-helix in the middle of the molecule, a characteristic beta-barrel known as the "oligosaccharide/oligonucleotide fold" at the N-terminal domain and a beta-grasp motif at the C-terminal domain. Each superantigen possesses slightly different binding mode(s) when it interacts with MHC class II molecules or the T-cell receptor.<a class="footnote-ref" id="fnref:6" href="#fn:6"><sup>6</sup></a>
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<h3>N-terminal domain</h3>
<p>The <a href="/facts/N-terminal/yKYpuaBJ">N-terminal</a> domain is also referred to as <a href="/facts/OB-fold/PPA8dm4c">OB-fold</a>, or in other words the oligonuclucleotide binding fold. This region contains a low-affinity major histocompatibility complex class II (<a href="/facts/MHC_II/nQ4hkBgW">MHC II</a>) site which causes an <a href="/facts/Inflammation/Ura86MIy">inflammatory response</a>.<a class="footnote-ref" id="fnref:7" href="#fn:7"><sup>7</sup></a>
</p><p>The N-terminal <a href="/facts/Protein_domain/oUpFcSsl">domain</a> contains regions involved in Major Histocompatibility Complex class II association. It is a five stranded <a href="/facts/Beta_barrel/8UMBqHQh">beta barrel</a> that forms an <a href="/facts/OB-fold/PPA8dm4c">OB fold</a>.<a class="footnote-ref" id="fnref:8" href="#fn:8"><sup>8</sup></a><a class="footnote-ref" id="fnref:9" href="#fn:9"><sup>9</sup></a><a class="footnote-ref" id="fnref:10" href="#fn:10"><sup>10</sup></a>
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<h3>C-terminal domain</h3>
<p>The beta-grasp domain has some structural similarities to the beta-grasp motif present in immunoglobulin-binding domains, ubiquitin, 2Fe-2 S ferredoxin and translation initiation factor 3 as identified by the SCOP database.
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This article incorporates text from the public domain <a href="/facts/Pfam/BKJa293w">Pfam</a> and <a href="/facts/InterPro/pKwNm8t7">InterPro</a>: <a href="https://www.ebi.ac.uk/interpro/entry/IPR006123">IPR006123</a>
This article incorporates text from the public domain <a href="/facts/Pfam/BKJa293w">Pfam</a> and <a href="/facts/InterPro/pKwNm8t7">InterPro</a>: <a href="https://www.ebi.ac.uk/interpro/entry/IPR006173">IPR006173</a>

<h2 id="references">References</h2>

<ol>
<li id="fn:1"><p>"eMedicine - CBRNE - Staphylococcal Enterotoxin B". eMedicine. Retrieved 2011-02-06. <a href="http://emedicine.medscape.com/article/830715-overview" target="_blank">http://emedicine.medscape.com/article/830715-overview</a> <a href="#fnref:1" class="footnote-back-ref">↩</a></p></li>
<li id="fn:2"><p>Nema V, Agrawal R, Kamboj DV, Goel AK, Singh L (June 2007). "Isolation and characterization of heat resistant enterotoxigenic Staphylococcus aureus from a food poisoning outbreak in Indian subcontinent". Int. J. Food Microbiol. 117 (1): 29–35. doi:10.1016/j.ijfoodmicro.2007.01.015. PMID 17477998. <a href="/wiki/Doi_(identifier)" target="_blank">/wiki/Doi_(identifier)</a> <a href="#fnref:2" class="footnote-back-ref">↩</a></p></li>
<li id="fn:3"><p>"eMedicine - CBRNE - Staphylococcal Enterotoxin B". eMedicine. Retrieved 2011-02-06. <a href="http://emedicine.medscape.com/article/830715-overview" target="_blank">http://emedicine.medscape.com/article/830715-overview</a> <a href="#fnref:3" class="footnote-back-ref">↩</a></p></li>
<li id="fn:4"><p>Blomster-Hautamaa DA, Kreiswirth BN, Kornblum JS, Novick RP, Schlievert PM (November 1986). "The nucleotide and partial amino acid sequence of toxic shock syndrome toxin-1". J. Biol. Chem. 261 (33): 15783–6. doi:10.1016/S0021-9258(18)66787-0. PMID 3782090. <a href="https://doi.org/10.1016%2FS0021-9258%2818%2966787-0" target="_blank">https://doi.org/10.1016%2FS0021-9258%2818%2966787-0</a> <a href="#fnref:4" class="footnote-back-ref">↩</a></p></li>
<li id="fn:5"><p>Blomster-Hautamaa DA, Kreiswirth BN, Kornblum JS, Novick RP, Schlievert PM (November 1986). "The nucleotide and partial amino acid sequence of toxic shock syndrome toxin-1". J. Biol. Chem. 261 (33): 15783–6. doi:10.1016/S0021-9258(18)66787-0. PMID 3782090. <a href="https://doi.org/10.1016%2FS0021-9258%2818%2966787-0" target="_blank">https://doi.org/10.1016%2FS0021-9258%2818%2966787-0</a> <a href="#fnref:5" class="footnote-back-ref">↩</a></p></li>
<li id="fn:6"><p>Acharya KR, Papageorgiou AC, Tranter HS (1998). "Crystal structure of microbial superantigen staphylococcal enterotoxin B at 1.5 A resolution: implications for superantigen recognition by MHC class II molecules and T-cell receptors". J. Mol. Biol. 277 (1): 61–79. doi:10.1006/jmbi.1997.1577. PMID 9514739. <a href="/wiki/Doi_(identifier)" target="_blank">/wiki/Doi_(identifier)</a> <a href="#fnref:6" class="footnote-back-ref">↩</a></p></li>
<li id="fn:7"><p>Brosnahan AJ, Schlievert PM (December 2011). "Gram-positive bacterial superantigen outside-in signaling causes toxic shock syndrome". FEBS J. 278 (23): 4649–67. doi:10.1111/j.1742-4658.2011.08151.x. PMC 3165073. PMID 21535475. <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3165073" target="_blank">https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3165073</a> <a href="#fnref:7" class="footnote-back-ref">↩</a></p></li>
<li id="fn:8"><p>Prasad GS, Earhart CA, Murray DL, Novick RP, Schlievert PM, Ohlendorf DH (December 1993). "Structure of toxic shock syndrome toxin 1". Biochemistry. 32 (50): 13761–6. doi:10.1021/bi00213a001. PMID 8268150. <a href="/wiki/Doi_(identifier)" target="_blank">/wiki/Doi_(identifier)</a> <a href="#fnref:8" class="footnote-back-ref">↩</a></p></li>
<li id="fn:9"><p>Acharya KR, Passalacqua EF, Jones EY, Harlos K, Stuart DI, Brehm RD, Tranter HS (January 1994). "Structural basis of superantigen action inferred from crystal structure of toxic-shock syndrome toxin-1". Nature. 367 (6458): 94–7. Bibcode:1994Natur.367...94A. doi:10.1038/367094a0. PMID 8107781. S2CID 4235964. <a href="/wiki/Bibcode_(identifier)" target="_blank">/wiki/Bibcode_(identifier)</a> <a href="#fnref:9" class="footnote-back-ref">↩</a></p></li>
<li id="fn:10"><p>Prasad GS, Radhakrishnan R, Mitchell DT, Earhart CA, Dinges MM, Cook WJ, Schlievert PM, Ohlendorf DH (June 1997). "Refined structures of three crystal forms of toxic shock syndrome toxin-1 and of a tetramutant with reduced activity". Protein Sci. 6 (6): 1220–7. doi:10.1002/pro.5560060610. PMC 2143723. PMID 9194182. <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2143723" target="_blank">https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2143723</a> <a href="#fnref:10" class="footnote-back-ref">↩</a></p></li>
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Enterotoxin type B open-in-new

Enterotoxin type B