View source for 1qpo


==Quinolinate Phosphoribosyl Transferase (QAPRTase) Apo-Enzyme from Mycobacterium Tuberculosis==
<StructureSection load='1qpo' size='340' side='right'caption='[[1qpo]], [[Resolution|resolution]] 2.40&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[1qpo]] is a 6 chain structure with sequence from [https://en.wikipedia.org/wiki/Mycobacterium_tuberculosis_H37Rv Mycobacterium tuberculosis H37Rv]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1QPO OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=1QPO 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]] 2.4&#8491;</td></tr>
<tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=SO4:SULFATE+ION'>SO4</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=1qpo FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=1qpo OCA], [https://pdbe.org/1qpo PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=1qpo RCSB], [https://www.ebi.ac.uk/pdbsum/1qpo PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=1qpo ProSAT], [https://www.topsan.org/Proteins/TBSGC/1qpo TOPSAN]</span></td></tr>
</table>
== Function ==
[https://www.uniprot.org/uniprot/NADC_MYCTU NADC_MYCTU] Involved in the catabolism of quinolinic acid (QA) (By similarity).
== 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/qp/1qpo_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=1qpo ConSurf].
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== Publication Abstract from PubMed ==
Background:. Mycobacterium tuberculosis is the single most deadly human pathogen and is responsible for nearly three million deaths every year. Recent elucidation of the mode of action of isoniazid, a frontline antimycobacterial drug, suggests that NAD metabolism is extremely critical for this microorganism. M. tuberculosis depends solely on the de novo pathway to meet its NAD demand. Quinolinic acid phosphoribosyltransferase (QAPRTase), a key enzyme in the de novo biosynthesis of NAD, provides an attractive target for designing novel antitubercular drugs. Results:. The X-ray crystal structure of the M. tuberculosis QAPRTase apoenzyme has been determined by multiple isomorphous replacement at 2.4 A resolution. Structures of the enzyme have also been solved in complex with the substrate quinolinic acid (QA), the inhibitory QA analog phthalic acid (PA), the product nicotinate mononucleotide (NAMN), and as a ternary complex with PA and a substrate analog, 5-phosphoribosyl-1-(beta-methylene)pyrophosphate (PRPCP). The structure of the nonproductive QAPRTase-PA-PRPCP Michaelis complex reveals a 5-phosphoribosyl-1-pyrophosphate-binding site that is different from the one observed in type I phosphoribosyltransferases (PRTases). The type II PRTase active site of QAPRTase undergoes conformational changes that appear to be important in determining substrate specificity and eliciting productive catalysis. Conclusions:. QAPRTase is the only known representative of the type II PRTase fold, an unusual alpha/beta barrel, and appears to represent convergent evolution for PRTase catalysis. The active site of type II PRTase bears little resemblance to the better known type I enzymes.

Crystal structure of quinolinic acid phosphoribosyltransferase from Mmycobacterium tuberculosis: a potential TB drug target.,Sharma V, Grubmeyer C, Sacchettini JC Structure. 1998 Dec 15;6(12):1587-99. PMID:9862811<ref>PMID:9862811</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 1qpo" style="background-color:#fffaf0;"></div>

==See Also==
*[[Phosphoribosyltransferase 3D structures|Phosphoribosyltransferase 3D structures]]
== References ==
<references/>
__TOC__
</StructureSection>
[[Category: Large Structures]]
[[Category: Mycobacterium tuberculosis H37Rv]]
[[Category: Grubmeyer C]]
[[Category: Sacchettini JC]]
[[Category: Sharma V]]