View source for 1nx6


==Crystal Structure of Aspartate Semialdehyde Dehydrogenase from Haemophilus influenzae as a Tetrahedral Hemithiocetal Reaction intermediate with Phosphate at 2.15 A==
<StructureSection load='1nx6' size='340' side='right'caption='[[1nx6]], [[Resolution|resolution]] 2.15&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[1nx6]] is a 1 chain structure with sequence from [https://en.wikipedia.org/wiki/Haemophilus_influenzae Haemophilus influenzae]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1NX6 OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=1NX6 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]] 2.15&#8491;</td></tr>
<tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=HTI:(4S)-4-{[(2S)-2-AMINO-3-OXOPROPYL]SULFANYL}-L-HOMOSERINE'>HTI</scene>, <scene name='pdbligand=PO4:PHOSPHATE+ION'>PO4</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=1nx6 FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=1nx6 OCA], [https://pdbe.org/1nx6 PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=1nx6 RCSB], [https://www.ebi.ac.uk/pdbsum/1nx6 PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=1nx6 ProSAT]</span></td></tr>
</table>
== Function ==
[https://www.uniprot.org/uniprot/DHAS_HAEIN DHAS_HAEIN] Catalyzes the NADPH-dependent formation of L-aspartate-semialdehyde (L-ASA) by the reductive dephosphorylation of L-aspartyl-4-phosphate.<ref>PMID:12071715</ref> 
== 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/nx/1nx6_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=1nx6 ConSurf].
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== Publication Abstract from PubMed ==
The structural analysis of an enzymatic reaction intermediate affords a unique opportunity to study a catalytic mechanism in extraordinary detail. Here we present the structure of a tetrahedral intermediate in the catalytic cycle of aspartate-beta-semialdehyde dehydrogenase (ASADH) from Haemophilus influenzae at 2.0-A resolution. ASADH is not found in humans, yet its catalytic activity is required for the biosynthesis of essential amino acids in plants and microorganisms. Diaminopimelic acid, also formed by this enzymatic pathway, is an integral component of bacterial cell walls, thus making ASADH an attractive target for the development of new antibiotics. This enzyme is able to capture the substrates aspartate-beta-semialdehyde and phosphate as an active complex that does not complete the catalytic cycle in the absence of NADP. A distinctive binding pocket in which the hemithioacetal oxygen of the bound substrate is stabilized by interaction with a backbone amide group dictates the R stereochemistry of the tetrahedral intermediate. This pocket, reminiscent of the oxyanion hole found in serine proteases, is completed through hydrogen bonding to the bound phosphate substrate.

Capture of an intermediate in the catalytic cycle of L-aspartate-beta-semialdehyde dehydrogenase.,Blanco J, Moore RA, Viola RE Proc Natl Acad Sci U S A. 2003 Oct 28;100(22):12613-7. Epub 2003 Oct 14. PMID:14559965<ref>PMID:14559965</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 1nx6" style="background-color:#fffaf0;"></div>

==See Also==
*[[Aspartate-semialdehyde dehydrogenase 3D structures|Aspartate-semialdehyde dehydrogenase 3D structures]]
== References ==
<references/>
__TOC__
</StructureSection>
[[Category: Haemophilus influenzae]]
[[Category: Large Structures]]
[[Category: Blanco J]]
[[Category: Moore RA]]
[[Category: Viola RE]]