8dnc: Difference between revisions
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== Structural highlights == | == Structural highlights == | ||
<table><tr><td colspan='2'>[[8dnc]] is a 4 chain structure with sequence from [https://en.wikipedia.org/wiki/Aquifex_aeolicus_VF5 Aquifex aeolicus VF5]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=8DNC OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=8DNC FirstGlance]. <br> | <table><tr><td colspan='2'>[[8dnc]] is a 4 chain structure with sequence from [https://en.wikipedia.org/wiki/Aquifex_aeolicus_VF5 Aquifex aeolicus VF5]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=8DNC OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=8DNC FirstGlance]. <br> | ||
</td></tr><tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=ADP:ADENOSINE-5-DIPHOSPHATE'>ADP</scene>, <scene name='pdbligand=MG:MAGNESIUM+ION'>MG</scene>, <scene name='pdbligand=UBH:3-O-methyl-alpha-D-rhamnopyranose'>UBH</scene>, <scene name='pdbligand=UBO:beta-D-rhamnopyranose'>UBO</scene>, <scene name='pdbligand=XXR:6-DEOXY-ALPHA-D-MANNOPYRANOSE'>XXR</scene></td></tr> | </td></tr><tr id='method'><td class="sblockLbl"><b>[[Empirical_models|Method:]]</b></td><td class="sblockDat" id="methodDat">Electron Microscopy, [[Resolution|Resolution]] 3.3Å</td></tr> | ||
<tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=ADP:ADENOSINE-5-DIPHOSPHATE'>ADP</scene>, <scene name='pdbligand=MG:MAGNESIUM+ION'>MG</scene>, <scene name='pdbligand=UBH:3-O-methyl-alpha-D-rhamnopyranose'>UBH</scene>, <scene name='pdbligand=UBO:beta-D-rhamnopyranose'>UBO</scene>, <scene name='pdbligand=XXR:6-DEOXY-ALPHA-D-MANNOPYRANOSE'>XXR</scene></td></tr> | |||
<tr id='resources'><td class="sblockLbl"><b>Resources:</b></td><td class="sblockDat"><span class='plainlinks'>[https://proteopedia.org/fgij/fg.htm?mol=8dnc FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=8dnc OCA], [https://pdbe.org/8dnc PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=8dnc RCSB], [https://www.ebi.ac.uk/pdbsum/8dnc PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=8dnc ProSAT]</span></td></tr> | <tr id='resources'><td class="sblockLbl"><b>Resources:</b></td><td class="sblockDat"><span class='plainlinks'>[https://proteopedia.org/fgij/fg.htm?mol=8dnc FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=8dnc OCA], [https://pdbe.org/8dnc PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=8dnc RCSB], [https://www.ebi.ac.uk/pdbsum/8dnc PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=8dnc ProSAT]</span></td></tr> | ||
</table> | </table> | ||
== Function == | == Function == | ||
[https://www.uniprot.org/uniprot/O67181_AQUAE O67181_AQUAE] | |||
<div style="background-color:#fffaf0;"> | <div style="background-color:#fffaf0;"> | ||
== Publication Abstract from PubMed == | == Publication Abstract from PubMed == | ||
O antigens are ubiquitous protective extensions of lipopolysaccharides in the extracellular leaflet of the Gram-negative outer membrane. Following biosynthesis in the cytosol, the lipid-linked polysaccharide is transported to the periplasm by the WzmWzt ABC transporter. Often, O antigen secretion requires the chemical modification of its elongating terminus, which the transporter recognizes via a carbohydrate-binding domain (CBD). Here, using components from A. aeolicus, we identify the O antigen structure with methylated mannose or rhamnose as its cap. Crystal and cryo electron microscopy structures reveal how WzmWzt recognizes this cap between its carbohydrate and nucleotide-binding domains in a nucleotide-free state. ATP binding induces drastic conformational changes of its CBD, terminating interactions with the O antigen. ATPase assays and site directed mutagenesis reveal reduced hydrolytic activity upon O antigen binding, likely to facilitate polymer loading into the ABC transporter. Our results elucidate critical steps in the recognition and translocation of polysaccharides by ABC transporters. | O antigens are ubiquitous protective extensions of lipopolysaccharides in the extracellular leaflet of the Gram-negative outer membrane. Following biosynthesis in the cytosol, the lipid-linked polysaccharide is transported to the periplasm by the WzmWzt ABC transporter. Often, O antigen secretion requires the chemical modification of its elongating terminus, which the transporter recognizes via a carbohydrate-binding domain (CBD). Here, using components from A. aeolicus, we identify the O antigen structure with methylated mannose or rhamnose as its cap. Crystal and cryo electron microscopy structures reveal how WzmWzt recognizes this cap between its carbohydrate and nucleotide-binding domains in a nucleotide-free state. ATP binding induces drastic conformational changes of its CBD, terminating interactions with the O antigen. ATPase assays and site directed mutagenesis reveal reduced hydrolytic activity upon O antigen binding, likely to facilitate polymer loading into the ABC transporter. Our results elucidate critical steps in the recognition and translocation of polysaccharides by ABC transporters. | ||
, PMID:36064941<ref>PMID:36064941</ref> | |||
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.<br> | From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.<br> | ||
