View source for 1qwj


==The Crystal Structure of Murine CMP-5-N-Acetylneuraminic Acid Synthetase==
<StructureSection load='1qwj' size='340' side='right'caption='[[1qwj]], [[Resolution|resolution]] 2.80&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[1qwj]] is a 4 chain structure with sequence from [http://en.wikipedia.org/wiki/Lk3_transgenic_mice Lk3 transgenic mice]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1QWJ OCA]. For a <b>guided tour on the structure components</b> use [http://proteopedia.org/fgij/fg.htm?mol=1QWJ FirstGlance]. <br>
</td></tr><tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=NCC:CYTIDINE-5-MONOPHOSPHATE-5-N-ACETYLNEURAMINIC+ACID'>NCC</scene></td></tr>
<tr id='related'><td class="sblockLbl"><b>[[Related_structure|Related:]]</b></td><td class="sblockDat"><div style='overflow: auto; max-height: 3em;'>[[1eyr|1eyr]], [[1gqc|1gqc]]</div></td></tr>
<tr id='gene'><td class="sblockLbl"><b>[[Gene|Gene:]]</b></td><td class="sblockDat">Cmas ([http://www.ncbi.nlm.nih.gov/Taxonomy/Browser/wwwtax.cgi?mode=Info&srchmode=5&id=10090 LK3 transgenic mice])</td></tr>
<tr id='activity'><td class="sblockLbl"><b>Activity:</b></td><td class="sblockDat"><span class='plainlinks'>[http://en.wikipedia.org/wiki/N-acylneuraminate_cytidylyltransferase N-acylneuraminate cytidylyltransferase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=2.7.7.43 2.7.7.43] </span></td></tr>
<tr id='resources'><td class="sblockLbl"><b>Resources:</b></td><td class="sblockDat"><span class='plainlinks'>[http://proteopedia.org/fgij/fg.htm?mol=1qwj FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=1qwj OCA], [http://pdbe.org/1qwj PDBe], [http://www.rcsb.org/pdb/explore.do?structureId=1qwj RCSB], [http://www.ebi.ac.uk/pdbsum/1qwj PDBsum], [http://prosat.h-its.org/prosat/prosatexe?pdbcode=1qwj ProSAT]</span></td></tr>
</table>
== Function ==
[[http://www.uniprot.org/uniprot/NEUA_MOUSE NEUA_MOUSE]] Catalyzes the activation of N-acetylneuraminic acid (NeuNAc) to cytidine 5'-monophosphate N-acetylneuraminic acid (CMP-NeuNAc), a substrate required for the addition of sialic acid. Has some activity toward NeuNAc, N-glycolylneuraminic acid (Neu5Gc) or 2-keto-3-deoxy-D-glycero-D-galacto-nononic acid (KDN).<ref>PMID:9689047</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/qw/1qwj_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=1qwj ConSurf].
<div style="clear:both"></div>
<div style="background-color:#fffaf0;">
== Publication Abstract from PubMed ==
Sialic acids are activated by CMP-5-N-acetylneuraminic acid synthetase prior to their transfer onto oligo- or polysaccharides. Here, we present the crystal structure of the N-terminal catalytically active domain of the murine 5-N-acetylneuraminic acid synthetase in complex with the reaction product. In contrast to the previously solved structure of 5-N-acetylneuraminic acid synthetase from Neisseria meningitidis and the related CMP-KDO-synthetase of Escherichia coli, the murine enzyme is a tetramer, which was observed with the active sites closed. In this conformation a loop is shifted by 6A towards the active site and thus an essential arginine residue can participate in catalysis. Furthermore, a network of intermolecular salt-bridges and hydrogen bonds in the dimer as well as hydrophobic interfaces between two dimers indicate a cooperative behaviour of the enzyme. In addition, a complex regulation of the enzyme activity is proposed that includes phosphorylation and dephosphorylation.

The crystal structure of murine CMP-5-N-acetylneuraminic acid synthetase.,Krapp S, Munster-Kuhnel AK, Kaiser JT, Huber R, Tiralongo J, Gerardy-Schahn R, Jacob U J Mol Biol. 2003 Dec 5;334(4):625-37. PMID:14636592<ref>PMID:14636592</ref>

From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
</div>
<div class="pdbe-citations 1qwj" style="background-color:#fffaf0;"></div>
== References ==
<references/>
__TOC__
</StructureSection>
[[Category: Large Structures]]
[[Category: Lk3 transgenic mice]]
[[Category: N-acylneuraminate cytidylyltransferase]]
[[Category: Gerardy-Schahn, R]]
[[Category: Huber, R]]
[[Category: Jacob, U]]
[[Category: Kaiser, J T]]
[[Category: Krapp, S]]
[[Category: Muenster-Kuehnel, A K]]
[[Category: Tiralongo, J]]
[[Category: Cmp-5-n-acetylneuraminic acid synthetase]]
[[Category: Cmp-neu5ac]]
[[Category: Glycosylation]]
[[Category: Lipopolysaccharide biosynthesis]]
[[Category: Sialic acid]]
[[Category: Sugar-activating enzyme]]
[[Category: Transferase]]