View source for 1gq9


==THE STRUCTURE OF CMP:2-KETO-3-DEOXY-MANNO-OCTONIC ACID SYNTHETASE COMPLEXED WITH CTP at 100K==
<StructureSection load='1gq9' size='340' side='right'caption='[[1gq9]], [[Resolution|resolution]] 2.60&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[1gq9]] is a 2 chain structure with sequence from [https://en.wikipedia.org/wiki/Escherichia_coli Escherichia coli]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=1GQ9 OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=1GQ9 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]] 2.6&#8491;</td></tr>
<tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=CTP:CYTIDINE-5-TRIPHOSPHATE'>CTP</scene>, <scene name='pdbligand=MG:MAGNESIUM+ION'>MG</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=1gq9 FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=1gq9 OCA], [https://pdbe.org/1gq9 PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=1gq9 RCSB], [https://www.ebi.ac.uk/pdbsum/1gq9 PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=1gq9 ProSAT]</span></td></tr>
</table>
== Function ==
[https://www.uniprot.org/uniprot/KPSU5_ECOLX KPSU5_ECOLX] Activates KDO (a required 8-carbon sugar) for incorporation into bacterial lipopolysaccharide in Gram-negative bacteria.
== 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/gq/1gq9_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=1gq9 ConSurf].
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== Publication Abstract from PubMed ==
The activation of the sugar 2-keto-3-deoxy-manno-octonic acid (Kdo) is catalyzed by CMP-Kdo synthetase (EC 2.7.7.38) and results in a monophosphate diester with CMP. The enzyme is a pharmaceutical target because CMP-Kdo is required for the biosynthesis of lipopolysaccharides that are vital for Gram-negative bacteria. We have established the structures of an enzyme complex with the educt CTP and of a complex with the product CMP-Kdo by X-ray diffraction analyses at 100 K, both at 2.6 A resolution. The N-terminal domains of the dimeric enzyme bind CTP in a peculiar nucleotide-binding fold with the beta- and gamma-phosphates located at the so-called "PP-loop", whereas the C-terminal domains participate in Kdo binding and in the dimer interface. The unstable nucleotide-sugar CMP-Kdo was produced in a crystal and stabilized by freezing to 100 K. Its formation is accompanied by an induced fit involving mainchain displacements in the 2 A range. The observed binding conformations together with the amino acid conservation pattern during evolution and the putative location of the required Mg(2+) ion suggest a reaction pathway. The enzyme is structurally homologous to the CMP-N-acetylneuraminic acid synthetases in all parts except for the dimer interface. Moreover, the chainfold and the substrate-binding positions resemble those of other enzymes processing nucleotide sugars.

Catalytic mechanism of CMP:2-keto-3-deoxy-manno-octonic acid synthetase as derived from complexes with reaction educt and product.,Jelakovic S, Schulz GE Biochemistry. 2002 Jan 29;41(4):1174-81. PMID:11802716<ref>PMID:11802716</ref>

From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
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== References ==
<references/>
__TOC__
</StructureSection>
[[Category: Escherichia coli]]
[[Category: Large Structures]]
[[Category: Jelakovic S]]
[[Category: Schulz GE]]