2ppf: Difference between revisions

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[[Image:2ppf.jpg|left|200px]]


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==Reduced mutant D98N of AfNiR exposed to nitric oxide==
The line below this paragraph, containing "STRUCTURE_2ppf", creates the "Structure Box" on the page.
<StructureSection load='2ppf' size='340' side='right'caption='[[2ppf]], [[Resolution|resolution]] 1.65&Aring;' scene=''>
You may change the PDB parameter (which sets the PDB file loaded into the applet)  
== Structural highlights ==
or the SCENE parameter (which sets the initial scene displayed when the page is loaded),
<table><tr><td colspan='2'>[[2ppf]] is a 3 chain structure with sequence from [https://en.wikipedia.org/wiki/Alcaligenes_faecalis Alcaligenes faecalis]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=2PPF OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=2PPF FirstGlance]. <br>
or leave the SCENE parameter empty for the default display.
</td></tr><tr id='method'><td class="sblockLbl"><b>[[Empirical_models|Method:]]</b></td><td class="sblockDat" id="methodDat">X-ray diffraction, [[Resolution|Resolution]] 1.65&#8491;</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=NO:NITRIC+OXIDE'>NO</scene>, <scene name='pdbligand=TRS:2-AMINO-2-HYDROXYMETHYL-PROPANE-1,3-DIOL'>TRS</scene></td></tr>
{{STRUCTURE_2ppf| PDB=2ppf |  SCENE= }}
<tr id='resources'><td class="sblockLbl"><b>Resources:</b></td><td class="sblockDat"><span class='plainlinks'>[https://proteopedia.org/fgij/fg.htm?mol=2ppf FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=2ppf OCA], [https://pdbe.org/2ppf PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=2ppf RCSB], [https://www.ebi.ac.uk/pdbsum/2ppf PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=2ppf ProSAT]</span></td></tr>
</table>
== Function ==
[https://www.uniprot.org/uniprot/NIR_ALCFA NIR_ALCFA]
== Evolutionary Conservation ==
[[Image:Consurf_key_small.gif|200px|right]]
Check<jmol>
  <jmolCheckbox>
    <scriptWhenChecked>; select protein; define ~consurf_to_do selected; consurf_initial_scene = true; script "/wiki/ConSurf/pp/2ppf_consurf.spt"</scriptWhenChecked>
    <scriptWhenUnchecked>script /wiki/extensions/Proteopedia/spt/initialview01.spt</scriptWhenUnchecked>
    <text>to colour the structure by Evolutionary Conservation</text>
  </jmolCheckbox>
</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=2ppf ConSurf].
<div style="clear:both"></div>


'''Reduced mutant D98N of AfNiR exposed to nitric oxide'''
==See Also==
 
*[[Nitrite reductase 3D structures|Nitrite reductase 3D structures]]
 
__TOC__
==Overview==
</StructureSection>
Nitrite 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.
 
==About this Structure==
2PPF is a [[Single protein]] structure of sequence from [http://en.wikipedia.org/wiki/Alcaligenes_faecalis Alcaligenes faecalis]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=2PPF OCA].
 
==Reference==
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:[http://www.ncbi.nlm.nih.gov/pubmed/17924665 17924665]
[[Category: Alcaligenes faecalis]]
[[Category: Alcaligenes faecalis]]
[[Category: Single protein]]
[[Category: Large Structures]]
[[Category: Murphy, M E.P.]]
[[Category: Murphy MEP]]
[[Category: Tocheva, E I.]]
[[Category: Tocheva EI]]
[[Category: Bacteria]]
[[Category: Copper]]
[[Category: D98n]]
[[Category: Denitrification]]
[[Category: Nitric oxide]]
[[Category: Nitrite reductase]]
[[Category: Oxidoreductase]]
''Page seeded by [http://oca.weizmann.ac.il/oca OCA ] on Sun May  4 13:35:08 2008''