2pp9

<table><tr><td colspan='2'>[[2pp9]] 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=2PP9 OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=2PP9 FirstGlance]. <br>

</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=NO3:NITRATE+ION'>NO3</scene>, <scene name='pdbligand=TRS:2-AMINO-2-HYDROXYMETHYL-PROPANE-1,3-DIOL'>TRS</scene></td></tr>

<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>

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== Publication Abstract from PubMed ==

The interaction of copper-containing dissimilatory nitrite reductase from Alcaligenes faecalis S-6 ( AfNiR) with each of five small molecules was studied using crystallography and steady-state kinetics. Structural studies revealed that each small molecule interacted with the oxidized catalytic type 2 copper of AfNiR. Three small molecules (formate, acetate and nitrate) mimic the substrate by having at least two oxygen atoms for bidentate coordination to the type 2 copper atom. These three anions bound to the copper ion in the same asymmetric, bidentate manner as nitrite. Consistent with their weak inhibition of the enzyme ( K i &gt;50 mM), the Cu-O distances in these AfNiR-inhibitor complexes were approximately 0.15 A longer than that observed in the AfNiR-nitrite complex. The binding mode of each inhibitor is determined in part by steric interactions with the side chain of active site residue Ile257. Moreover, the side chain of Asp98, a conserved residue that hydrogen bonds to type 2 copper-bound nitrite and nitric oxide, was either disordered or pointed away from the inhibitors. Acetate and formate inhibited AfNiR in a mixed fashion, consistent with the occurrence of second acetate binding site in the AfNiR-acetate complex that occludes access to the type 2 copper. A fourth small molecule, nitrous oxide, bound to the oxidized metal in a side-on fashion reminiscent of nitric oxide to the reduced copper. Nevertheless, nitrous oxide bound at a farther distance from the metal. The fifth small molecule, azide, inhibited the reduction of nitrite by AfNiR most strongly ( K ic = 2.0 +/- 0.1 mM). This ligand bound to the type 2 copper center end-on with a Cu-N c distance of approximately 2 A, and was the only inhibitor to form a hydrogen bond with Asp98. Overall, the data substantiate the roles of Asp98 and Ile257 in discriminating substrate from other small anions.

Conserved Active Site Residues Limit Inhibition of a Copper-Containing Nitrite Reductase by Small Molecules.,Tocheva EI, Eltis LD, Murphy ME Biochemistry. 2008 Mar 22;. PMID:18358002<ref>PMID:18358002</ref>

From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>

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== References ==

<references/>

[[Category: Alcfa]]

[[Category: Murphy, M E.P]]

[[Category: Tocheva, E I]]

[[Category: Oxidoreductase]]