3x21

<StructureSection load='3x21' size='340' side='right'caption='[[3x21]], [[Resolution|resolution]] 3.00&Aring;' scene=''>

<table><tr><td colspan='2'>[[3x21]] is a 10 chain structure. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=3X21 OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=3X21 FirstGlance]. <br>

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

<tr id='resources'><td class="sblockLbl"><b>Resources:</b></td><td class="sblockDat"><span class='plainlinks'>[https://proteopedia.org/fgij/fg.htm?mol=3x21 FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=3x21 OCA], [https://pdbe.org/3x21 PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=3x21 RCSB], [https://www.ebi.ac.uk/pdbsum/3x21 PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=3x21 ProSAT]</span></td></tr>

== Function ==

[[https://www.uniprot.org/uniprot/NFNB_ECOLI NFNB_ECOLI]] Reduction of a variety of nitroaromatic compounds using NADH (and to lesser extent NADPH) as source of reducing equivalents; two electrons are transferred. Capable of reducing nitrofurazone, quinones and the anti-tumor agent CB1954 (5-(aziridin-1-yl)-2,4-dinitrobenzamide). The reduction of CB1954 results in the generation of cytotoxic species.<ref>PMID:15684426</ref>

<div style="background-color:#fffaf0;">

== Publication Abstract from PubMed ==

Nitroreductases have great potential for the highly efficient reduction of aryl nitro compounds to arylhydroxylamines. However, regioselective reduction of the desired nitro group in polynitroarenes is still a challenge. Here, we describe the structure-based engineering of Escherichia coli nitroreductase NfsB to alter its regioselectivity, in order to achieve reduction of a target nitro group. When 2,4-dinitrotoluene was used as the substrate, the wild-type enzyme regioselectively reduced the 4-NO2 group, but the T41L/N71S/F124W mutant primarily reduced the 2-NO2 group, without loss of activity. The crystal structure of T41L/N71S/F124W and docking experiments indicated that the regioselectivity change (from 4-NO2 to 2-NO2 ) might result from the increased hydrophobicity of residues 41 and 124 (proximal to FMN) and conformational changes in residues 70 and 124.

Altering the regioselectivity of a nitroreductase in the synthesis of arylhydroxylamines by structure-based engineering.,Bai J, Zhou Y, Chen Q, Yang Q, Yang J Chembiochem. 2015 May 26;16(8):1219-25. doi: 10.1002/cbic.201500070. Epub 2015, Apr 27. PMID:25917861<ref>PMID:25917861</ref>

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

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<div class="pdbe-citations 3x21" style="background-color:#fffaf0;"></div>

== References ==

<references/>

[[Category: 6,7-dihydropteridine reductase]]

[[Category: Bai, J]]

[[Category: Yang, J]]

[[Category: Yang, Q]]

[[Category: Zhou, Y]]

[[Category: Regioselectivity]]