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1e54

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(New page: 200px<br /><applet load="1e54" size="450" color="white" frame="true" align="right" spinBox="true" caption="1e54, resolution 2.1&Aring;" /> '''ANION-SELECTIVE PORIN...)
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[[Image:1e54.gif|left|200px]]<br /><applet load="1e54" size="450" color="white" frame="true" align="right" spinBox="true"
 
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caption="1e54, resolution 2.1&Aring;" />
 
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'''ANION-SELECTIVE PORIN FROM COMAMONAS ACIDOVORANS'''<br />
 
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==Overview==
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==Anion-selective porin from Comamonas acidovorans==
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BACKGROUND: Porins provide diffusion channels for salts and small organic, molecules in the outer membrane of bacteria. In OmpF from Escherichia coli, and related porins, an electrostatic field across the channel and a, potential, originating from a surplus of negative charges, create moderate, cation selectivity. Here, we investigate the strongly anion-selective, porin Omp32 from Comamonas acidovorans, which is closely homologous to the, porins of pathogenic Bordetella and Neisseria species. RESULTS: The, crystal structure of Omp32 was determined to a resolution of 2.1 A using, single isomorphous replacement with anomalous scattering (SIRAS). The, porin consists of a 16-stranded beta barrel with eight external loops and, seven periplasmic turns. Loops 3 and 8, together with a protrusion located, within beta-strand 2, narrow the cross-section of the pore considerably., Arginine residues create a charge filter in the constriction zone and a, positive surface potential at the external and periplasmic faces. One, sulfate ion was bound to Arg38 in the channel constriction zone. A peptide, of 5.8 kDa appeared bound to Omp32 in a 1:1 stoichiometry on the, periplasmic side close to the symmetry axis of the trimer. Eight amino, acids of this peptide could be identified, revealing specific interactions, with beta-strand 1 of the porin. CONCLUSIONS: The Omp32 structure explains, the strong anion selectivity of this porin. Selectivity is conferred by a, positive potential, which is not attenuated by negative charges inside the, channel, and by an extremely narrow constriction zone. Moreover, Omp32, represents the anchor molecule for a peptide which is homologous to, proteins that link the outer membrane to the cell wall peptidoglycan.
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<StructureSection load='1e54' size='340' side='right'caption='[[1e54]], [[Resolution|resolution]] 2.10&Aring;' scene=''>
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== Structural highlights ==
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<table><tr><td colspan='2'>[[1e54]] is a 2 chain structure with sequence from [https://en.wikipedia.org/wiki/Delftia_acidovorans Delftia acidovorans]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1E54 OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=1E54 FirstGlance]. <br>
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</td></tr><tr id='method'><td class="sblockLbl"><b>[[Empirical_models|Method:]]</b></td><td class="sblockDat" id="methodDat">X-ray diffraction, [[Resolution|Resolution]] 2.1&#8491;</td></tr>
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<tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=CA:CALCIUM+ION'>CA</scene>, <scene name='pdbligand=PCA:PYROGLUTAMIC+ACID'>PCA</scene>, <scene name='pdbligand=SO4:SULFATE+ION'>SO4</scene></td></tr>
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<tr id='resources'><td class="sblockLbl"><b>Resources:</b></td><td class="sblockDat"><span class='plainlinks'>[https://proteopedia.org/fgij/fg.htm?mol=1e54 FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=1e54 OCA], [https://pdbe.org/1e54 PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=1e54 RCSB], [https://www.ebi.ac.uk/pdbsum/1e54 PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=1e54 ProSAT]</span></td></tr>
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</table>
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== Function ==
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[https://www.uniprot.org/uniprot/OMP32_DELAC OMP32_DELAC]
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== Evolutionary Conservation ==
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[[Image:Consurf_key_small.gif|200px|right]]
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Check<jmol>
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<jmolCheckbox>
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<scriptWhenChecked>; select protein; define ~consurf_to_do selected; consurf_initial_scene = true; script "/wiki/ConSurf/e5/1e54_consurf.spt"</scriptWhenChecked>
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<scriptWhenUnchecked>script /wiki/extensions/Proteopedia/spt/initialview01.spt</scriptWhenUnchecked>
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<text>to colour the structure by Evolutionary Conservation</text>
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</jmolCheckbox>
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</jmol>, as determined by [http://consurfdb.tau.ac.il/ ConSurfDB]. You may read the [[Conservation%2C_Evolutionary|explanation]] of the method and the full data available from [http://bental.tau.ac.il/new_ConSurfDB/main_output.php?pdb_ID=1e54 ConSurf].
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<div style="clear:both"></div>
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==About this Structure==
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==See Also==
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1E54 is a [http://en.wikipedia.org/wiki/Protein_complex Protein complex] structure of sequences from [http://en.wikipedia.org/wiki/Delftia_acidovorans Delftia acidovorans] with CA and SO4 as [http://en.wikipedia.org/wiki/ligands ligands]. Full crystallographic information is available from [http://ispc.weizmann.ac.il/oca-bin/ocashort?id=1E54 OCA].
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*[[Porin 3D structures|Porin 3D structures]]
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__TOC__
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==Reference==
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</StructureSection>
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Crystal structure of Omp32, the anion-selective porin from Comamonas acidovorans, in complex with a periplasmic peptide at 2.1 A resolution., Zeth K, Diederichs K, Welte W, Engelhardt H, Structure. 2000 Sep 15;8(9):981-92. PMID:[http://ispc.weizmann.ac.il//pmbin/getpm?pmid=10986465 10986465]
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[[Category: Delftia acidovorans]]
[[Category: Delftia acidovorans]]
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[[Category: Protein complex]]
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[[Category: Large Structures]]
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[[Category: Diederichs, K.]]
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[[Category: Diederichs K]]
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[[Category: Engelhardt, H.]]
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[[Category: Engelhardt H]]
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[[Category: Welte, W.]]
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[[Category: Welte W]]
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[[Category: Zeth, K.]]
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[[Category: Zeth K]]
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[[Category: CA]]
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[[Category: SO4]]
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[[Category: anionen channel]]
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[[Category: beta barrel]]
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[[Category: channel protein]]
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[[Category: outer membrane protein]]
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''Page seeded by [http://ispc.weizmann.ac.il/oca OCA ] on Tue Nov 20 13:46:53 2007''
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Current revision

Anion-selective porin from Comamonas acidovorans

PDB ID 1e54

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