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== Function == | == Function == | ||
[[http://www.uniprot.org/uniprot/Q9K169_NEIMB Q9K169_NEIMB]] Stereospecific condensation of phosphoenolpyruvate (PEP) and D-erythrose-4-phosphate (E4P) giving rise to 3-deoxy-D-arabino-heptulosonate-7-phosphate (DAHP) (By similarity).[PIRNR:PIRNR001361] | [[http://www.uniprot.org/uniprot/Q9K169_NEIMB Q9K169_NEIMB]] Stereospecific condensation of phosphoenolpyruvate (PEP) and D-erythrose-4-phosphate (E4P) giving rise to 3-deoxy-D-arabino-heptulosonate-7-phosphate (DAHP) (By similarity).[PIRNR:PIRNR001361] | ||
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== Publication Abstract from PubMed == | |||
Neisseria meningitidis 3-deoxy-d-arabino-heptulosonate 7-phosphate synthase (NmeDAH7PS) adopts a homotetrameric structure consisting of an extensive and a less extensive interface. Perturbation of the less extensive interface through a single mutation of a salt bridge (Arg126-Glu27) formed at the tetramer interface of all chains resulted in a dimeric DAH7PS in solution, as determined by small angle X-ray scattering, analytical ultracentrifugation and analytical size-exclusion chromatography. The dimeric NmeDAH7PSR126S variant was shown to be catalytically active in the aldol-like condensation reaction between d-erythrose 4-phosphate and phosphoenolpyruvate, and allosterically inhibited by l-phenylalanine to the same extent as the wild-type enzyme. The dimeric NmeDAH7PSR126S variant exhibited a slight reduction in thermal stability by differential scanning calorimetry experiments and a slow loss of activity over time compared to the wild-type enzyme. Although NmeDAH7PSR126S crystallised as a tetramer, like the wild-type enzyme, structural asymmetry at the less extensive interface was observed consistent with its destabilisation. The tetrameric association enabled by this Arg126-Glu27 salt-bridge appears to contribute solely to the stability of the protein, ultimately revealing that the functional unit of NmeDAH7PS is dimeric. | |||
The Functional Unit of Neisseria meningitidis 3-Deoxy--Arabino-Heptulosonate 7-Phosphate Synthase Is Dimeric.,Cross PJ, Heyes LC, Zhang S, Nazmi AR, Parker EJ PLoS One. 2016 Feb 1;11(2):e0145187. doi: 10.1371/journal.pone.0145187., eCollection 2016. PMID:26828675<ref>PMID:26828675</ref> | |||
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.<br> | |||
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== References == | |||
<references/> | |||
__TOC__ | __TOC__ | ||
</StructureSection> | </StructureSection> | ||
Revision as of 17:18, 5 October 2016
Neisseria meningitidis 3-deoxy-D-arabino-heptulosonate 7-phosphate synthase regulated (Tryptophan)Neisseria meningitidis 3-deoxy-D-arabino-heptulosonate 7-phosphate synthase regulated (Tryptophan)
Structural highlights
Function[Q9K169_NEIMB] Stereospecific condensation of phosphoenolpyruvate (PEP) and D-erythrose-4-phosphate (E4P) giving rise to 3-deoxy-D-arabino-heptulosonate-7-phosphate (DAHP) (By similarity).[PIRNR:PIRNR001361] Publication Abstract from PubMedNeisseria meningitidis 3-deoxy-d-arabino-heptulosonate 7-phosphate synthase (NmeDAH7PS) adopts a homotetrameric structure consisting of an extensive and a less extensive interface. Perturbation of the less extensive interface through a single mutation of a salt bridge (Arg126-Glu27) formed at the tetramer interface of all chains resulted in a dimeric DAH7PS in solution, as determined by small angle X-ray scattering, analytical ultracentrifugation and analytical size-exclusion chromatography. The dimeric NmeDAH7PSR126S variant was shown to be catalytically active in the aldol-like condensation reaction between d-erythrose 4-phosphate and phosphoenolpyruvate, and allosterically inhibited by l-phenylalanine to the same extent as the wild-type enzyme. The dimeric NmeDAH7PSR126S variant exhibited a slight reduction in thermal stability by differential scanning calorimetry experiments and a slow loss of activity over time compared to the wild-type enzyme. Although NmeDAH7PSR126S crystallised as a tetramer, like the wild-type enzyme, structural asymmetry at the less extensive interface was observed consistent with its destabilisation. The tetrameric association enabled by this Arg126-Glu27 salt-bridge appears to contribute solely to the stability of the protein, ultimately revealing that the functional unit of NmeDAH7PS is dimeric. The Functional Unit of Neisseria meningitidis 3-Deoxy--Arabino-Heptulosonate 7-Phosphate Synthase Is Dimeric.,Cross PJ, Heyes LC, Zhang S, Nazmi AR, Parker EJ PLoS One. 2016 Feb 1;11(2):e0145187. doi: 10.1371/journal.pone.0145187., eCollection 2016. PMID:26828675[1] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. References
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