2ppc: Difference between revisions
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==Oxidized wild type AfNiR exposed to NO (nitrite bound)== | ==Oxidized wild type AfNiR exposed to NO (nitrite bound)== | ||
<StructureSection load='2ppc' size='340' side='right' caption='[[2ppc]], [[Resolution|resolution]] 1.58Å' scene=''> | <StructureSection load='2ppc' size='340' side='right'caption='[[2ppc]], [[Resolution|resolution]] 1.58Å' scene=''> | ||
== Structural highlights == | == Structural highlights == | ||
<table><tr><td colspan='2'>[[2ppc]] is a 3 chain structure with sequence from [ | <table><tr><td colspan='2'>[[2ppc]] is a 3 chain structure with sequence from [https://en.wikipedia.org/wiki/Alcfa Alcfa]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=2PPC OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=2PPC FirstGlance]. <br> | ||
</td></tr><tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat"><scene name='pdbligand=ACT:ACETATE+ION'>ACT</scene>, <scene name='pdbligand=CU:COPPER+(II)+ION'>CU</scene>, <scene name='pdbligand=CU1:COPPER+(I)+ION'>CU1</scene>, <scene name='pdbligand=NO2:NITRITE+ION'>NO2</scene>, <scene name='pdbligand=TRS:2-AMINO-2-HYDROXYMETHYL-PROPANE-1,3-DIOL'>TRS</scene></td></tr> | </td></tr><tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=ACT:ACETATE+ION'>ACT</scene>, <scene name='pdbligand=CU:COPPER+(II)+ION'>CU</scene>, <scene name='pdbligand=CU1:COPPER+(I)+ION'>CU1</scene>, <scene name='pdbligand=NO2:NITRITE+ION'>NO2</scene>, <scene name='pdbligand=TRS:2-AMINO-2-HYDROXYMETHYL-PROPANE-1,3-DIOL'>TRS</scene></td></tr> | ||
<tr id='related'><td class="sblockLbl"><b>[[Related_structure|Related:]]</b></td><td class="sblockDat">[[1snr|1snr]], [[1sjm|1sjm]]</td></tr> | <tr id='related'><td class="sblockLbl"><b>[[Related_structure|Related:]]</b></td><td class="sblockDat"><div style='overflow: auto; max-height: 3em;'>[[1snr|1snr]], [[1sjm|1sjm]]</div></td></tr> | ||
<tr id='gene'><td class="sblockLbl"><b>[[Gene|Gene:]]</b></td><td class="sblockDat">nirK, nir ([ | <tr id='gene'><td class="sblockLbl"><b>[[Gene|Gene:]]</b></td><td class="sblockDat">nirK, nir ([https://www.ncbi.nlm.nih.gov/Taxonomy/Browser/wwwtax.cgi?mode=Info&srchmode=5&id=511 ALCFA])</td></tr> | ||
<tr id='activity'><td class="sblockLbl"><b>Activity:</b></td><td class="sblockDat"><span class='plainlinks'>[ | <tr id='activity'><td class="sblockLbl"><b>Activity:</b></td><td class="sblockDat"><span class='plainlinks'>[https://en.wikipedia.org/wiki/Nitrite_reductase_(NO-forming) Nitrite reductase (NO-forming)], with EC number [https://www.brenda-enzymes.info/php/result_flat.php4?ecno=1.7.2.1 1.7.2.1] </span></td></tr> | ||
<tr id='resources'><td class="sblockLbl"><b>Resources:</b></td><td class="sblockDat"><span class='plainlinks'>[ | <tr id='resources'><td class="sblockLbl"><b>Resources:</b></td><td class="sblockDat"><span class='plainlinks'>[https://proteopedia.org/fgij/fg.htm?mol=2ppc FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=2ppc OCA], [https://pdbe.org/2ppc PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=2ppc RCSB], [https://www.ebi.ac.uk/pdbsum/2ppc PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=2ppc ProSAT]</span></td></tr> | ||
</table> | </table> | ||
== Evolutionary Conservation == | == Evolutionary Conservation == | ||
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==See Also== | ==See Also== | ||
*[[Nitrite reductase|Nitrite reductase]] | *[[Nitrite reductase 3D structures|Nitrite reductase 3D structures]] | ||
== References == | == References == | ||
<references/> | <references/> | ||
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</StructureSection> | </StructureSection> | ||
[[Category: Alcfa]] | [[Category: Alcfa]] | ||
[[Category: Large Structures]] | |||
[[Category: Murphy, M E.P]] | [[Category: Murphy, M E.P]] | ||
[[Category: Tocheva, E I]] | [[Category: Tocheva, E I]] |
Revision as of 18:29, 17 June 2021
Oxidized wild type AfNiR exposed to NO (nitrite bound)Oxidized wild type AfNiR exposed to NO (nitrite bound)
Structural highlights
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 PubMedNitrite reductase (NiR) is an enzyme that uses type 1 and type 2 copper sites to reduce nitrite to nitric oxide during bacterial denitrification. A copper-nitrosyl intermediate is a proposed, yet poorly characterized feature of the NiR catalytic cycle. This intermediate is formally described as Cu(I)-NO+ and is proposed to be formed at the type 2 copper site after nitrite binding and electron transfer from the type 1 copper site. In this study, copper-nitrosyl complexes were formed by prolonged exposure of exogenous NO to crystals of wild-type and two variant forms of NiR from Alcaligenes faecalis (AfNiR), and the structures were determined to 1.8 A or better resolution. Exposing oxidized wild-type crystals to NO results in the reverse reaction and formation of nitrite that remains bound at the active site. In a type 1 copper site mutant (H145A) that is incapable of electron transfer to the type 2 site, the reverse reaction is not observed. Instead, in both oxidized and reduced H145A crystals, NO is observed bound in a side-on manner to the type 2 copper. In AfNiR, Asp98 forms hydrogen bonds to both substrate and product bound to the type 2 Cu. In the D98N variant, NO is bound side-on but is more disordered when observed for the wild-type enzyme. The solution EPR spectra of the crystallographically characterized NiR-NO complexes indicate the presence of an oxidized type 2 copper site and thus are interpreted as resulting from stable copper-nitrosyls and formally assigned as Cu(II)-NO-. A reaction scheme in which a second NO molecule is oxidized to nitrite can account for the formation of a Cu(II)-NO- species after exposure of the oxidized H145A variant to NO gas. Stable copper-nitrosyl formation by nitrite reductase in either oxidation state.,Tocheva EI, Rosell FI, Mauk AG, Murphy ME Biochemistry. 2007 Oct 30;46(43):12366-74. Epub 2007 Oct 9. PMID:17924665[1] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See AlsoReferences
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