View source for 4jtj


==Crystal structure of R117K mutant of 3-deoxy-D-manno-octulosonate 8-phosphate synthase (KDO8PS) from Neisseria meningitidis==
<StructureSection load='4jtj' size='340' side='right'caption='[[4jtj]], [[Resolution|resolution]] 1.75&Aring;' scene=''>
== Structural highlights ==
<table><tr><td colspan='2'>[[4jtj]] is a 4 chain structure with sequence from [https://en.wikipedia.org/wiki/Neisseria_meningitidis_MC58 Neisseria meningitidis MC58]. Full crystallographic information is available from [http://oca.weizmann.ac.il/oca-bin/ocashort?id=4JTJ OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=4JTJ 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]] 1.75&#8491;</td></tr>
<tr id='ligand'><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat" id="ligandDat"><scene name='pdbligand=CL:CHLORIDE+ION'>CL</scene>, <scene name='pdbligand=NA:SODIUM+ION'>NA</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=4jtj FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=4jtj OCA], [https://pdbe.org/4jtj PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=4jtj RCSB], [https://www.ebi.ac.uk/pdbsum/4jtj PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=4jtj ProSAT]</span></td></tr>
</table>
== Function ==
[https://www.uniprot.org/uniprot/KDSA_NEIMB KDSA_NEIMB] 
<div style="background-color:#fffaf0;">
== Publication Abstract from PubMed ==
3-Deoxy-d-manno-octulosonate 8-phosphate synthase (KDO8PS) catalyzes the reaction between phosphoenolpyruvate and arabinose 5-phosphate (A5P) in the first committed step in the pathway to 3-deoxy-d-manno-octulosonate, a component in the cell wall of Gram-negative bacteria. KDO8PS is evolutionarily and structurally related to the first enzyme of the shikimate pathway, 3-deoxy-d-arabino-heptulosonate 7-phosphate synthase (DAH7PS), which uses erythrose 4-phosphate in place of A5P. Both KDO8PS and type Ibeta DAH7PS enzymes adopt similar homotetrameric associations with their active sites close to one of the interfaces. The conserved PAFLxR motif in KDO8PS and the corresponding GARNxQ motif in type Ibeta DAH7PS, both on the short beta4-alpha4 loop of the (beta/alpha)8 barrel, form part of this interface and provide key contacts with substrates. This 112PAFLxR117 motif was mutated in Neisseria meningitidis KDO8PS in order to assess its role in enzyme function. Arg117 extends across the interface to provide guanidinium functionality in the A5P binding site of the adjacent subunit. Substitution Arg117Ala severely hampered catalysis, whereas substitution to Lys was tolerated better. Mutation of Phe114 to either Arg or Ala results in active proteins, but with substantially elevated KmA5P values. Mutant proteins that combine substitutions in this motif demonstrate poor catalytic function, and, although these mutated residues now structurally resemble their counterparts in the GARNxQ motif of type Ibeta DAH7PS, no DAH7PS-like activity was observed. Analysis of the structures reveals that small changes in relative orientation of the subunits are important for the differences in active-site construction. Quaternary structure is therefore tightly linked to substrate specificity.

Examining the Role of Intersubunit Contacts in Catalysis by 3-Deoxy-d-manno-octulosonate 8-Phosphate Synthase.,Allison TM, Cochrane FC, Jameson GB, Parker EJ Biochemistry. 2013 Jun 26. PMID:23746359<ref>PMID:23746359</ref>

From MEDLINE&reg;/PubMed&reg;, a database of the U.S. National Library of Medicine.<br>
</div>
<div class="pdbe-citations 4jtj" style="background-color:#fffaf0;"></div>

==See Also==
*[[Kdo-8-phosphate synthase|Kdo-8-phosphate synthase]]
== References ==
<references/>
__TOC__
</StructureSection>
[[Category: Large Structures]]
[[Category: Neisseria meningitidis MC58]]
[[Category: Allison TM]]
[[Category: Cochrane FC]]
[[Category: Jameson GB]]
[[Category: Parker EJ]]