1eu4

<table><tr><td colspan='2'>[[1eu4]] is a 1 chain structure with sequence from [https://en.wikipedia.org/wiki/"micrococcus_scarlatinae"_klein_1884 "micrococcus scarlatinae" klein 1884]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1EU4 OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=1EU4 FirstGlance]. <br>

</td></tr><tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=ZN:ZINC+ION'>ZN</scene></td></tr>

<tr id='related'><td class="sblockLbl"><b>[[Related_structure|Related:]]</b></td><td class="sblockDat"><div style='overflow: auto; max-height: 3em;'>[[1et6|1et6]], [[1et9|1et9]], [[1eu3|1eu3]]</div></td></tr>

[[https://www.uniprot.org/uniprot/SPEH_STRPY SPEH_STRPY]] Mitogenic for human peripheral blood lymphocytes.

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== Publication Abstract from PubMed ==

Bacterial superantigens (SAgs) are a structurally related group of protein toxins secreted by Staphylococcus aureus and Streptococcus pyogenes. They are implicated in a range of human pathologies associated with bacterial infection whose symptoms result from SAg-mediated stimulation of a large number (2-20%) of T-cells. At the molecular level, bacterial SAgs bind to major histocompatability class II (MHC-II) molecules and disrupt the normal interaction between MHC-II and T-cell receptors (TCRs). We have determined high-resolution crystal structures of two newly identified streptococcal superantigens, SPE-H and SMEZ-2. Both structures conform to the generic bacterial superantigen folding pattern, comprising an OB-fold N-terminal domain and a beta-grasp C-terminal domain. SPE-H and SMEZ-2 also display very similar zinc-binding sites on the outer concave surfaces of their C-terminal domains. Structural comparisons with other SAgs identify two structural sub-families. Sub-families are related by conserved core residues and demarcated by variable binding surfaces for MHC-II and TCR. SMEZ-2 is most closely related to the streptococcal SAg SPE-C, and together they constitute one structural sub-family. In contrast, SPE-H appears to be a hybrid whose N-terminal domain is most closely related to the SEB sub-family and whose C-terminal domain is most closely related to the SPE-C/SMEZ-2 sub-family. MHC-II binding for both SPE-H and SMEZ-2 is mediated by the zinc ion at their C-terminal face, whereas the generic N-terminal domain MHC-II binding site found on many SAgs appears not to be present. Structural comparisons provide evidence for variations in TCR binding between SPE-H, SMEZ-2 and other members of the SAg family; the extreme potency of SMEZ-2 (active at 10(-15) g ml-1 levels) is likely to be related to its TCR binding properties. The smez gene shows allelic variation that maps onto a considerable proportion of the protein surface. This allelic variation, coupled with the varied binding modes of SAgs to MHC-II and TCR, highlights the pressure on SAgs to avoid host immune defences.

Conservation and variation in superantigen structure and activity highlighted by the three-dimensional structures of two new superantigens from Streptococcus pyogenes.,Arcus VL, Proft T, Sigrell JA, Baker HM, Fraser JD, Baker EN J Mol Biol. 2000 May 26;299(1):157-68. PMID:10860729<ref>PMID:10860729</ref>

From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>

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== References ==

<references/>

[[Category: Micrococcus scarlatinae klein 1884]]

[[Category: Arcus, V L]]

[[Category: Baker, E N]]

[[Category: Baker, H M]]

[[Category: Fraser, J D]]

[[Category: Proft, T]]

[[Category: Sigrell, J A]]

[[Category: Beta grasp]]

[[Category: Superantigen fold]]