View source for 2qtn


==Crystal Structure of Nicotinate Mononucleotide Adenylyltransferase==
<StructureSection load='2qtn' size='340' side='right'caption='[[2qtn]], [[Resolution|resolution]] 2.40&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[2qtn]] is a 2 chain structure with sequence from [https://en.wikipedia.org/wiki/Bacillus_anthracis Bacillus anthracis]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=2QTN OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=2QTN 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=GOL:GLYCEROL'>GOL</scene>, <scene name='pdbligand=MG:MAGNESIUM+ION'>MG</scene>, <scene name='pdbligand=NCN:NICOTINATE+MONONUCLEOTIDE'>NCN</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=2qtn FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=2qtn OCA], [https://pdbe.org/2qtn PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=2qtn RCSB], [https://www.ebi.ac.uk/pdbsum/2qtn PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=2qtn ProSAT]</span></td></tr>
</table>
== 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/qt/2qtn_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=2qtn ConSurf].
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== Publication Abstract from PubMed ==
Biosynthesis of NAD(P) in bacteria occurs either de novo or through one of the salvage pathways that converge at the point where the reaction of nicotinate mononucleotide (NaMN) with ATP is coupled to the formation of nicotinate adenine dinucleotide (NaAD) and inorganic pyrophosphate. This reaction is catalyzed by nicotinate mononucleotide adenylyltransferase (NMAT), which is essential for bacterial growth, making it an attractive drug target for the development of new antibiotics. Steady-state kinetic and direct binding studies on NMAT from Bacillus anthracis suggest a random sequential Bi-Bi kinetic mechanism. Interestingly, the interactions of NaMN and ATP with NMAT were observed to exhibit negative cooperativity, i.e. Hill coefficients &lt;1.0. Negative cooperativity in binding is supported by the results of X-ray crystallographic studies. X-ray structures of the B. anthracis NMAT apoenzyme, and the NaMN- and NaAD-bound complexes were determined to resolutions of 2.50 A, 2.60 A and 1.75 A, respectively. The X-ray structure of the NMAT-NaMN complex revealed only one NaMN molecule bound in the biological dimer, supporting negative cooperativity in substrate binding. The kinetic, direct-binding, and X-ray structural studies support a model in which the binding affinity of substrates to the first monomer of NMAT is stronger than that to the second, and analysis of the three X-ray structures reveals significant conformational changes of NMAT along the enzymatic reaction coordinate. The negative cooperativity observed in B. anthracis NMAT substrate binding is a unique property that has not been observed in other prokaryotic NMAT enzymes. We propose that regulation of the NAD(P) biosynthetic pathway may occur, in part, at the reaction catalyzed by NMAT.

Kinetic and X-ray structural evidence for negative cooperativity in substrate binding to nicotinate mononucleotide adenylyltransferase (NMAT) from Bacillus anthracis.,Sershon VC, Santarsiero BD, Mesecar AD J Mol Biol. 2009 Jan 23;385(3):867-88. Epub 2008 Oct 19. PMID:18977360<ref>PMID:18977360</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 2qtn" style="background-color:#fffaf0;"></div>
== References ==
<references/>
__TOC__
</StructureSection>
[[Category: Bacillus anthracis]]
[[Category: Large Structures]]
[[Category: Mesecar AD]]
[[Category: Santarsiero BD]]
[[Category: Sershon VC]]