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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 [http://en.wikipedia.org/wiki/Neimb Neimb]. 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 [http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=3QPY FirstGlance]. <br> | |||
</td></tr><tr><td class="sblockLbl"><b>[[Ligand|Ligands:]]</b></td><td class="sblockDat"><scene name='pdbligand=CL:CHLORIDE+ION'>CL</scene>, <scene name='pdbligand=GOL:GLYCEROL'>GOL</scene>, <scene name='pdbligand=NA:SODIUM+ION'>NA</scene><br> | |||
<tr><td class="sblockLbl"><b>[[Related_structure|Related:]]</b></td><td class="sblockDat">[[3qpz|3qpz]], [[3qq0|3qq0]], [[3qq1|3qq1]]</td></tr> | |||
<tr><td class="sblockLbl"><b>[[Gene|Gene:]]</b></td><td class="sblockDat">kdsA, NMB1283 ([http://www.ncbi.nlm.nih.gov/Taxonomy/Browser/wwwtax.cgi?mode=Info&srchmode=5&id=122586 NEIMB])</td></tr> | |||
<tr><td class="sblockLbl"><b>Activity:</b></td><td class="sblockDat"><span class='plainlinks'>[http://en.wikipedia.org/wiki/3-deoxy-8-phosphooctulonate_synthase 3-deoxy-8-phosphooctulonate synthase], with EC number [http://www.brenda-enzymes.info/php/result_flat.php4?ecno=2.5.1.55 2.5.1.55] </span></td></tr> | |||
<tr><td class="sblockLbl"><b>Resources:</b></td><td class="sblockDat"><span class='plainlinks'>[http://oca.weizmann.ac.il/oca-docs/fgij/fg.htm?mol=3qpy FirstGlance], [http://oca.weizmann.ac.il/oca-bin/ocaids?id=3qpy OCA], [http://www.rcsb.org/pdb/explore.do?structureId=3qpy RCSB], [http://www.ebi.ac.uk/pdbsum/3qpy PDBsum]</span></td></tr> | |||
<table> | |||
<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> | |||
== References == | |||
<references/> | |||
__TOC__ | |||
</StructureSection> | |||
== | |||
< | |||
[[Category: 3-deoxy-8-phosphooctulonate synthase]] | [[Category: 3-deoxy-8-phosphooctulonate synthase]] | ||
[[Category: | [[Category: Neimb]] | ||
[[Category: Allison, T M.]] | [[Category: Allison, T M.]] | ||
[[Category: Jameson, G B.]] | [[Category: Jameson, G B.]] | ||
Revision as of 16:15, 18 May 2014
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
Publication 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. References
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