View source for 5kow


==Structure of rifampicin monooxygenase==
<StructureSection load='5kow' size='340' side='right'caption='[[5kow]], [[Resolution|resolution]] 2.10&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[5kow]] is a 1 chain structure with sequence from [https://en.wikipedia.org/wiki/Nocardia_farcinica Nocardia farcinica]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=5KOW OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=5KOW FirstGlance]. <br>
</td></tr><tr id='method'><td class="sblockLbl"><b>[[Empirical_models|Method:]]</b></td><td class="sblockDat" id="methodDat">X-ray diffraction, [[Resolution|Resolution]] 2.1&#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=FAD:FLAVIN-ADENINE+DINUCLEOTIDE'>FAD</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=5kow FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=5kow OCA], [https://pdbe.org/5kow PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=5kow RCSB], [https://www.ebi.ac.uk/pdbsum/5kow PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=5kow ProSAT]</span></td></tr>
</table>
== Function ==
[https://www.uniprot.org/uniprot/ROX_NOCFA ROX_NOCFA] Monooxygenase that can modify rifampicin, thereby inactivating its antibiotic activity (PubMed:19942945, PubMed:29578336). It constitutes a secondary rifampicin resistance factor (PubMed:19942945).<ref>PMID:19942945</ref> <ref>PMID:29578336</ref> 
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== Publication Abstract from PubMed ==
Rifampicin monooxygenase (RIFMO) catalyzes the N-hydroxylation of the natural product antibiotic rifampicin (RIF) to 2'-N-hydroxy-4-oxo-rifampicin, a metabolite with much lower antimicrobial activity. RIFMO shares moderate sequence similarity with well-characterized flavoprotein monooxygenases, but the protein has not been isolated and characterized at the molecular level. Herein, we report crystal structures of RIFMO from Nocardia farcinica, the determination of the oligomeric state in solution with small-angle X-ray scattering, and the spectrophotometric characterization of substrate binding. The structure identifies RIFMO as a class A flavoprotein monooxygenase and is similar in fold and quaternary structure to MtmOIV and OxyS, which are enzymes in the mithramycin and oxytetracycline biosynthetic pathways, respectively. RIFMO is distinguished from other class A flavoprotein monooxygenases by its unique middle domain, which is involved in binding RIF. Small-angle X-ray scattering analysis shows that RIFMO dimerizes via the FAD-binding domain to form a bell-shaped homodimer in solution with a maximal dimension of 110 A. RIF binding was monitored using absorbance at 525 nm to determine a dissociation constant of 13 muM. Steady-state oxygen consumption assays show that NADPH efficiently reduces the FAD only when RIF is present, implying that RIF binds before NADPH in the catalytic scheme. The 1.8 A resolution structure of RIFMO complexed with RIF represents the pre-catalytic conformation that occurs prior to formation of the ternary E-RIF-NADPH complex. The RIF naphthoquinone blocks access to the FAD N5 atom, implying that large conformational changes are required for NADPH to reduce the FAD. A model for these conformational changes is proposed.

The Structure of the Antibiotic Deactivating, N-hydroxylating Rifampicin Monooxygenase.,Liu LK, Abdelwahab H, Martin Del Campo JS, Mehra-Chaudhary R, Sobrado P, Tanner JJ J Biol Chem. 2016 Aug 24. pii: jbc.M116.745315. PMID:27557658<ref>PMID:27557658</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 5kow" style="background-color:#fffaf0;"></div>

==See Also==
*[[Monooxygenase 3D structures|Monooxygenase 3D structures]]
== References ==
<references/>
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</StructureSection>
[[Category: Large Structures]]
[[Category: Nocardia farcinica]]
[[Category: Liu L-K]]
[[Category: Tanner JJ]]