View source for 3dat


==Crystal structure of the ternary MTX NADPH complex of Bacillus anthracis dihydrofolate reductase==
<StructureSection load='3dat' size='340' side='right'caption='[[3dat]], [[Resolution|resolution]] 2.30&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[3dat]] is a 1 chain structure with sequence from [https://en.wikipedia.org/wiki/Bacillus_anthracis_str._Sterne Bacillus anthracis str. Sterne]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=3DAT OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=3DAT 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]] 2.3&#8491;</td></tr>
<tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=MTX:METHOTREXATE'>MTX</scene>, <scene name='pdbligand=NDP:NADPH+DIHYDRO-NICOTINAMIDE-ADENINE-DINUCLEOTIDE+PHOSPHATE'>NDP</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=3dat FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=3dat OCA], [https://pdbe.org/3dat PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=3dat RCSB], [https://www.ebi.ac.uk/pdbsum/3dat PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=3dat ProSAT]</span></td></tr>
</table>
== Function ==
[https://www.uniprot.org/uniprot/Q81R22_BACAN Q81R22_BACAN] Key enzyme in folate metabolism. Catalyzes an essential reaction for de novo glycine and purine synthesis, and for DNA precursor synthesis (By similarity).[PIRNR:PIRNR000194]
== 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/da/3dat_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=3dat ConSurf].
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== Publication Abstract from PubMed ==
For reasons of bioterrorism and drug resistance, it is imperative to identify and develop new molecular points of intervention against anthrax. Dihydrofolate reductase (DHFR) is a highly conserved enzyme and an established target in a number of species for a variety of chemotherapeutic programs. Recently, the crystal structure of Bacillus anthracis DHFR (baDHFR) in complex with methotrexate (MTX) was determined and, based on the structure, proposals were made for drug design strategies directed against the substrate-binding site. However, little is gleaned about the binding site for NADPH, the cofactor responsible for hydride transfer in the catalytic mechanism. In the present study, X-ray crystallography at 100 K was used to determine the structure of baDHFR in complex with MTX and NADPH. Although the NADPH binding mode is nearly identical to that seen in other DHFR ternary complex structures, the adenine moiety adopts an off-plane tilt of nearly 90 degrees and this orientation is stabilized by hydrogen bonds to functionally conserved Arg residues. A comparison of the binding site, focusing on this region, between baDHFR and the human enzyme is discussed, with an aim at designing species-selective therapeutics. Indeed, the ternary model, refined to 2.3 A resolution, provides an accurate template for testing the feasibility of identifying dual-site inhibitors, compounds that target both the substrate and cofactor-binding site. With the ternary model in hand, using in silico methods, several compounds were identified which could potentially form key bonding contacts in the substrate and cofactor-binding sites. Ultimately, two structurally distinct compounds were verified that inhibit baDHFR at low microM concentrations. The apparent Kd for one of these, (2-(3-(2-(hydroxyimino)-2-(pyridine-4-yl)-6,7-dimethylquinoxalin-2-yl)-1-( pyridine-4-yl)ethanone oxime), was measured by fluorescence spectroscopy to be 5.3 microM.

X-ray structure of the ternary MTX.NADPH complex of the anthrax dihydrofolate reductase: a pharmacophore for dual-site inhibitor design.,Bennett BC, Wan Q, Ahmad MF, Langan P, Dealwis CG J Struct Biol. 2009 May;166(2):162-71. PMID:19374017<ref>PMID:19374017</ref>

From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
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==See Also==
*[[Dihydrofolate reductase 3D structures|Dihydrofolate reductase 3D structures]]
== References ==
<references/>
__TOC__
</StructureSection>
[[Category: Bacillus anthracis str. Sterne]]
[[Category: Large Structures]]
[[Category: Bennett BC]]
[[Category: Dealwis CG]]