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1i4g

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Revision as of 06:56, 9 January 2019

Crystal structure of Staphylococcal enterotoxin A mutant H187A with reduced Zn2+ affinity

Structural highlights

1i4g is a 2 chain structure with sequence from "micrococcus_aureus"_(rosenbach_1884)_zopf_1885 "micrococcus aureus" (rosenbach 1884) zopf 1885. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance.
Ligands:	,
Related:	1sxt, 1efs, 1i4h
Resources:	FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT

Function

[ETXA_STAAU] Staphylococcal enterotoxins cause the intoxication staphylococcal food poisoning syndrome. The illness is characterized by high fever, hypotension, diarrhea, shock, and in some cases death.

Evolutionary Conservation

Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf.

Publication Abstract from PubMed

The structure of a mutant form of staphylococcal enterotoxin A (SEA) has been determined to 2.1 A resolution. The studied SEA substitution H187-->A187 (SEAH187A) leads to an almost 10-fold reduction of the binding to major histocompatibility complex (MHC) class II. H187 is important for this interaction since it coordinates Zn2+. The zinc ion is thought to hold MHC class II and SEA together in a complex. Interestingly, only one of two molecules in the asymmetric unit binds Zn2+. H225, D227, a water molecule, and H44 from a symmetry-related molecule ligate Zn2+. The symmetry-related histidine is necessary for this substituted Zn2+ site to bind to Zn2+ at low zinc concentration (no Zn2+ added). Since a water molecule replaces the missing H187, H44 binds Zn2+ at the position where betaH81 from MHC class II probably will bind. Dynamic light scattering analysis reveals that in solution as well as in the crystal lattice the SEA(H187A) mutant forms aggregates. The substitution per se does not cause aggregation since wild-type SEA also forms aggregates. Addition of EDTA reduces the size of the aggregates, indicating a cross-linking function of Zn2+. In agreement with the biological function, the aggregation is weak (i.e. not revealed by gel filtration) and non-specific.

Cooperative zinc binding in a staphylococcal enterotoxin A mutant mimics the SEA-MHC class II interaction.,Hakansson M, Antonsson P, Bjork P, Svensson LA J Biol Inorg Chem. 2001 Oct;6(8):757-62. PMID:11713682^[1]

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.

References

↑ Hakansson M, Antonsson P, Bjork P, Svensson LA. Cooperative zinc binding in a staphylococcal enterotoxin A mutant mimics the SEA-MHC class II interaction. J Biol Inorg Chem. 2001 Oct;6(8):757-62. PMID:11713682 doi:10.1007/s007750100251

1 Structural highlights
2 Function
3 Evolutionary Conservation
4 Publication Abstract from PubMed
5 References

Proteopedia Page Contributors and Editors (what is this?)

OCA

Retrieved from "http://52.214.119.220/wiki/index.php/1i4g"

@@ Line 3: / Line 3: @@
 <StructureSection load='1i4g' size='340' side='right' caption='[[1i4g]], [[Resolution|resolution]] 2.10&Aring;' scene=''>
 == Structural highlights ==
-<table><tr><td colspan='2'>[[1i4g]] is a 2 chain structure. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1I4G OCA]. For a <b>guided tour on the structure components</b> use [http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=1I4G FirstGlance]. <br>
+<table><tr><td colspan='2'>[[1i4g]] is a 2 chain structure with sequence from [http://en.wikipedia.org/wiki/"micrococcus_aureus"_(rosenbach_1884)_zopf_1885 "micrococcus aureus" (rosenbach 1884) zopf 1885]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1I4G OCA]. For a <b>guided tour on the structure components</b> use [http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=1I4G FirstGlance]. <br>
 </td></tr><tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat"><scene name='pdbligand=SO4:SULFATE+ION'>SO4</scene>, <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">[[1sxt|1sxt]], [[1efs|1efs]], [[1i4h|1i4h]]</td></tr>
@@ Line 14: / Line 14: @@
 Check<jmol>
   <jmolCheckbox>
-    <scriptWhenChecked>select protein; define ~consurf_to_do selected; consurf_initial_scene = true; script "/wiki/ConSurf/i4/1i4g_consurf.spt"</scriptWhenChecked>
+    <scriptWhenChecked>; select protein; define ~consurf_to_do selected; consurf_initial_scene = true; script "/wiki/ConSurf/i4/1i4g_consurf.spt"</scriptWhenChecked>
     <scriptWhenUnchecked>script /wiki/extensions/Proteopedia/spt/initialview01.spt</scriptWhenUnchecked>
     <text>to colour the structure by Evolutionary Conservation</text>

1i4g

From Proteopedia

Revision as of 06:56, 9 January 2019

Crystal structure of Staphylococcal enterotoxin A mutant H187A with reduced Zn2+ affinity

Structural highlights

Function

Evolutionary Conservation

Publication Abstract from PubMed

References

Contents

Proteopedia Page Contributors and Editors (what is this?)

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