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| | <StructureSection load='6d8v' size='340' side='right'caption='[[6d8v]], [[Resolution|resolution]] 2.80Å' scene=''> | | <StructureSection load='6d8v' size='340' side='right'caption='[[6d8v]], [[Resolution|resolution]] 2.80Å' scene=''> |
| | == Structural highlights == | | == Structural highlights == |
| - | <table><tr><td colspan='2'>[[6d8v]] is a 1 chain structure with sequence from [http://en.wikipedia.org/wiki/Ensifer_meliloti Ensifer meliloti]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=6D8V OCA]. For a <b>guided tour on the structure components</b> use [http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=6D8V FirstGlance]. <br> | + | <table><tr><td colspan='2'>[[6d8v]] is a 1 chain structure with sequence from [https://en.wikipedia.org/wiki/Sinorhizobium_meliloti_1021 Sinorhizobium meliloti 1021]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=6D8V OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=6D8V FirstGlance]. <br> |
| - | </td></tr><tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat"><scene name='pdbligand=PBE:1,1-DIMETHYL-PROLINIUM'>PBE</scene>, <scene name='pdbligand=TRS:2-AMINO-2-HYDROXYMETHYL-PROPANE-1,3-DIOL'>TRS</scene></td></tr> | + | </td></tr><tr id='method'><td class="sblockLbl"><b>[[Empirical_models|Method:]]</b></td><td class="sblockDat" id="methodDat">X-ray diffraction, [[Resolution|Resolution]] 2.8Å</td></tr> |
| - | <tr id='gene'><td class="sblockLbl"><b>[[Gene|Gene:]]</b></td><td class="sblockDat">mcpX, SMc01104 ([http://www.ncbi.nlm.nih.gov/Taxonomy/Browser/wwwtax.cgi?mode=Info&srchmode=5&id=266834 Ensifer meliloti])</td></tr>
| + | <tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=PBE:1,1-DIMETHYL-PROLINIUM'>PBE</scene>, <scene name='pdbligand=TRS:2-AMINO-2-HYDROXYMETHYL-PROPANE-1,3-DIOL'>TRS</scene></td></tr> |
| - | <tr id='resources'><td class="sblockLbl"><b>Resources:</b></td><td class="sblockDat"><span class='plainlinks'>[http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=6d8v FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=6d8v OCA], [http://pdbe.org/6d8v PDBe], [http://www.rcsb.org/pdb/explore.do?structureId=6d8v RCSB], [http://www.ebi.ac.uk/pdbsum/6d8v PDBsum], [http://prosat.h-its.org/prosat/prosatexe?pdbcode=6d8v 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=6d8v FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=6d8v OCA], [https://pdbe.org/6d8v PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=6d8v RCSB], [https://www.ebi.ac.uk/pdbsum/6d8v PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=6d8v ProSAT]</span></td></tr> |
| | </table> | | </table> |
| - | <div style="background-color:#fffaf0;">
| + | == Function == |
| - | == Publication Abstract from PubMed == | + | [https://www.uniprot.org/uniprot/Q92SH9_RHIME Q92SH9_RHIME] |
| - | The alpha-proteobacterium Sinorhizobium meliloti can live freely in the soil or engage in a symbiosis with its legume host. S. meliloti facilitates nitrogen fixation in root nodules, thus providing pivotal, utilizable nitrogen to the host. The organism has eight chemoreceptors, namely McpT to McpZ and IcpA that facilitate chemotaxis. McpX is the first known bacterial sensor of quaternary ammonium compounds (QACs) such as choline and betaines. Because QACs are exuded at chemotaxis-relevant concentrations by germinating alfalfa seeds, McpX has been proposed to contribute to host-specific chemotaxis. We have determined the crystal structure of the McpX periplasmic region (McpX(PR)) in complex with the proline betaine at 2.7 A resolution. In the crystal, the protein forms a symmetric dimer with one proline betaine molecule bound to each monomer of McpX(PR) within membrane-distal CACHE module. The ligand is bound through cation-piinteractions with four aromatic amino acid residues. Mutational analysis in conjunction with binding studies revealed that a conserved aspartate residue is pivotal for ligand binding. We discovered that, in a striking example of convergent evolution, the ligand-binding site of McpX(PR) resembles that of a group of structurally unrelated betaine-binding proteins including ProX and OpuAC. Through this comparison and docking studies, we rationalized the specificity of McpX(PR) for this specific group of ligands. Collectively, our structural, biochemical, and molecular docking data have revealed the molecular determinants in McpX that are crucial for its rare ligand specificity for QACs.
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| - | Structure of the sensory domain of McpX from Sinorhizobium meliloti, the first known bacterial chemotactic sensor for quaternary ammonium compounds.,Shrestha M, Compton KK, Mancl JM, Webb BA, Brown AM, Scharf BE, Schubot FD Biochem J. 2018 Dec 14;475(24):3949-3962. doi: 10.1042/BCJ20180769. PMID:30442721<ref>PMID:30442721</ref>
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| - | From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.<br>
| + | |
| - | </div>
| + | |
| - | <div class="pdbe-citations 6d8v" style="background-color:#fffaf0;"></div>
| + | |
| - | == References ==
| + | |
| - | <references/>
| + | |
| | __TOC__ | | __TOC__ |
| | </StructureSection> | | </StructureSection> |
| - | [[Category: Ensifer meliloti]] | |
| | [[Category: Large Structures]] | | [[Category: Large Structures]] |
| - | [[Category: Schubot, F D]] | + | [[Category: Sinorhizobium meliloti 1021]] |
| - | [[Category: Shrestha, M]] | + | [[Category: Schubot FD]] |
| - | [[Category: Chemotaxis]] | + | [[Category: Shrestha M]] |
| - | [[Category: Mcp]]
| + | |
| - | [[Category: Membrane protein]]
| + | |
