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==Crystal structure of a mutant (K57A) of 3-deoxy-D-manno-octulosonate 8-phosphate synthase (KDO8PS) from Neisseria meningitidis== | |||
<StructureSection load='3qpy' size='340' side='right'caption='[[3qpy]], [[Resolution|resolution]] 1.95Å' scene=''> | |||
== Structural highlights == | |||
<table><tr><td colspan='2'>[[3qpy]] 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=3QPY OCA]. For a <b>guided tour on the structure components</b> use [https://proteopedia.org/fgij/fg.htm?mol=3QPY 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]] 1.95Å</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=GOL:GLYCEROL'>GOL</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=3qpy FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=3qpy OCA], [https://pdbe.org/3qpy PDBe], [https://www.rcsb.org/pdb/explore.do?structureId=3qpy RCSB], [https://www.ebi.ac.uk/pdbsum/3qpy PDBsum], [https://prosat.h-its.org/prosat/prosatexe?pdbcode=3qpy 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-<i>manno</i>-octulosonate 8-phosphate synthase (KDO8PS) catalyzes the reaction between three-carbon phosphoenolpyruvate (PEP) and five-carbon D-arabinose 5-phosphate (A5P), generating KDO8P, a key intermediate in the biosynthetic pathway to 3-deoxy-D-<i>manno</i>-octulosonate, a component of the lipopolysaccharide of the Gram-negative bacterial cell wall. Both metal-dependent and metal-independent forms of KDO8PS have been characterized. KDO8PS is evolutionarily and mechanistically related to the first enzyme of the shikimate pathway, the obligately divalent metal-ion-dependent 3-deoxy-D-<i>arabino</i>-heptulosonate 7-phosphate synthase (DAH7PS) that couples PEP and four-carbon D-erythrose 4-phosphate (E4P) to give DAH7P. In KDO8PS an absolutely conserved KANRS motif forms part of the A5P binding site, whereas in DAH7PS an absolutely conserved KPR(S/T) motif accommodates E4P. Here, we have characterized four mutants of this motif (AANRS, KAARS, KARS and KPRS) in metal-dependent KDO8PS from <i>Acidithiobacillus ferrooxidans</i> and metal-independent KDO8PS from <i>Neisseria meningitidis</i> in order to test the roles of the universal Lys and the AlaAsn portion of the KANRS motif. The X-ray structures, determined for the <i>N. meningitidis</i> KDO8PS mutants, indicated no gross structural penalty resulting from mutation, but the subtle changes observed in the active sites of these mutant proteins correlated with their altered catalytic function: 1) the AANRS mutations destroyed catalytic activity; 2) the KAARS mutations lowered substrate selectivity, as well as activity; 3) replacing KANRS by KARS or KPRS destroyed KDO8PS activity, but did not produce a functional DAH7PS. Thus, Lys is critical to catalysis and other changes are necessary to switch substrate specificity for both the metal-independent and metal-dependent forms of these enzymes.<i></i> | |||
Targeting the role of a key conserved motif for substrate selection and catalysis by 3-deoxy-D-<i>manno</i>-octulosonate 8-phosphate synthase.,Allison TM, Hutton RD, Cochrane FC, Yeoman JA, Jameson GB, Parker EJ Biochemistry. 2011 Mar 25. PMID:21438567<ref>PMID:21438567</ref> | |||
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.<br> | |||
</div> | |||
<div class="pdbe-citations 3qpy" 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: Jameson GB]] | |||
[[Category: Parker EJ]] | |||
Latest revision as of 20:14, 1 November 2023
Crystal structure of a mutant (K57A) of 3-deoxy-D-manno-octulosonate 8-phosphate synthase (KDO8PS) from Neisseria meningitidisCrystal structure of a mutant (K57A) of 3-deoxy-D-manno-octulosonate 8-phosphate synthase (KDO8PS) from Neisseria meningitidis
Structural highlights
FunctionPublication Abstract from PubMed3-Deoxy-D-<i>manno</i>-octulosonate 8-phosphate synthase (KDO8PS) catalyzes the reaction between three-carbon phosphoenolpyruvate (PEP) and five-carbon D-arabinose 5-phosphate (A5P), generating KDO8P, a key intermediate in the biosynthetic pathway to 3-deoxy-D-<i>manno</i>-octulosonate, a component of the lipopolysaccharide of the Gram-negative bacterial cell wall. Both metal-dependent and metal-independent forms of KDO8PS have been characterized. KDO8PS is evolutionarily and mechanistically related to the first enzyme of the shikimate pathway, the obligately divalent metal-ion-dependent 3-deoxy-D-<i>arabino</i>-heptulosonate 7-phosphate synthase (DAH7PS) that couples PEP and four-carbon D-erythrose 4-phosphate (E4P) to give DAH7P. In KDO8PS an absolutely conserved KANRS motif forms part of the A5P binding site, whereas in DAH7PS an absolutely conserved KPR(S/T) motif accommodates E4P. Here, we have characterized four mutants of this motif (AANRS, KAARS, KARS and KPRS) in metal-dependent KDO8PS from <i>Acidithiobacillus ferrooxidans</i> and metal-independent KDO8PS from <i>Neisseria meningitidis</i> in order to test the roles of the universal Lys and the AlaAsn portion of the KANRS motif. The X-ray structures, determined for the <i>N. meningitidis</i> KDO8PS mutants, indicated no gross structural penalty resulting from mutation, but the subtle changes observed in the active sites of these mutant proteins correlated with their altered catalytic function: 1) the AANRS mutations destroyed catalytic activity; 2) the KAARS mutations lowered substrate selectivity, as well as activity; 3) replacing KANRS by KARS or KPRS destroyed KDO8PS activity, but did not produce a functional DAH7PS. Thus, Lys is critical to catalysis and other changes are necessary to switch substrate specificity for both the metal-independent and metal-dependent forms of these enzymes.<i></i> Targeting the role of a key conserved motif for substrate selection and catalysis by 3-deoxy-D-<i>manno</i>-octulosonate 8-phosphate synthase.,Allison TM, Hutton RD, Cochrane FC, Yeoman JA, Jameson GB, Parker EJ Biochemistry. 2011 Mar 25. PMID:21438567[1] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See AlsoReferences
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