1f8w

<table><tr><td colspan='2'>[[1f8w]] is a 1 chain structure with sequence from [https://en.wikipedia.org/wiki/"enterococcus_proteiformis"_thiercelin_and_jouhaud_1903 "enterococcus proteiformis" thiercelin and jouhaud 1903]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1F8W OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=1F8W FirstGlance]. <br>

</td></tr><tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=FAD:FLAVIN-ADENINE+DINUCLEOTIDE'>FAD</scene></td></tr>

<tr id='NonStdRes'><td class="sblockLbl"><b>[[Non-Standard_Residue|NonStd Res:]]</b></td><td class="sblockDat"><scene name='pdbligand=CSX:S-OXY+CYSTEINE'>CSX</scene></td></tr>

<tr id='related'><td class="sblockLbl"><b>[[Related_structure|Related:]]</b></td><td class="sblockDat"><div style='overflow: auto; max-height: 3em;'>[[1joa|1joa]], [[1nhp|1nhp]], [[1nhq|1nhq]], [[1nhr|1nhr]], [[1nhs|1nhs]], [[1npx|1npx]]</div></td></tr>

<tr id='activity'><td class="sblockLbl"><b>Activity:</b></td><td class="sblockDat"><span class='plainlinks'>[https://en.wikipedia.org/wiki/NADH_peroxidase NADH peroxidase], with EC number [https://www.brenda-enzymes.info/php/result_flat.php4?ecno=1.11.1.1 1.11.1.1] </span></td></tr>

[[https://www.uniprot.org/uniprot/NAPE_ENTFA NAPE_ENTFA]] Peroxidase whose active site is a redox-active cysteine-sulfenic acid.

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== Publication Abstract from PubMed ==

The crystal structure of the flavoprotein NADH peroxidase shows that the Arg303 side chain forms a hydrogen bond with the active-site His10 imidazole and is therefore likely to influence the catalytic mechanism. Dithionite titration of an R303M mutant [E(FAD, Cys42-sulfenic acid)] yields a two-electron reduced intermediate (EH(2)) with enhanced flavin fluorescence and almost no charge-transfer absorbance at pH 7.0; the pK(a) for the nascent Cys42-SH is increased by over 3.5 units in comparison with the wild-type EH(2) pK(a) of &lt;/=4.5. NADH titration of the mutant peroxidase yields the same EH(2) intermediate, but in contrast to the behavior of wild-type enzyme, this species can be reduced directly to an EH(4).NAD(+) complex. Kinetic analyses demonstrate that the R303M mutant is severely compromised, although active, with k(cat) = 3 s(-)(1) at pH 7.0, 5 degrees C; enzyme-monitored turnover results indicate that the steady-state consists predominantly of an E-FADH(2).NAD(+) species. When the oxidized mutant is reacted anaerobically with 0.9 equiv of NADH/FAD, a clearly biphasic pattern is observed at 450 nm; relatively rapid flavin reduction is followed by reoxidation at 2.6-2.7 s(-)(1) ( approximately k(cat)). Thus replacement of Arg303 with Met leads to an altered peroxidase form in which the rate-limiting step in turnover is the intramolecular transfer of electrons from FADH(2) --&gt; Cys42-SOH. The crystal structure of the R303M peroxidase has been refined at 2.45 A resolution. In addition to eliminating the Arg303 interactions with His10 and Glu14, the mutant exhibits a significant change in the conformation of the Cys42-SOH side chain relative to FAD and His10 in particular. These and other results provide a detailed understanding of Arg303 and its role in the structure and mechanism of this unique flavoprotein peroxidase.

Analysis of the kinetic and redox properties of the NADH peroxidase R303M mutant: correlation with the crystal structure.,Crane EJ 3rd, Yeh JI, Luba J, Claiborne A Biochemistry. 2000 Aug 29;39(34):10353-64. PMID:10956025<ref>PMID:10956025</ref>

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

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== References ==

<references/>

[[Category: Enterococcus proteiformis thiercelin and jouhaud 1903]]

[[Category: Claiborne, A]]

[[Category: Hol, W G.J]]

[[Category: Yeh, J I]]

[[Category: Oxidoreductase]]