Disease relevance of ECs1720

• The crystal structure of 3-deoxy-d-manno-octulosonate-8-phosphate synthase (KDOPS) from Escherichia coli was determined by molecular replacement using coordinates given to us by Radaev and co-workers prior to publication [1].
• A cDNA encoding 3-deoxy-D-manno-oct-2-ulosonate-8-phosphate synthase of Pisum sativum L. (pea) functionally complements a kdsA mutant of the Gram-negative bacterium Salmonella enterica [2].

High impact information on ECs1720

• The 13C NMR spectrum of an incubation mixture of [2-13C]PEP and D-arabinose 5-phosphate in 2H2 18O in the presence of KDO 8-P synthase was also recorded [3].
• However, the secondary, tertiary, and quaternary structures of DAHPS(Tm) are more similar to the functionally related enzyme, 3-deoxy-d-manno-octulosonate-8-phosphate synthase (KDOPS) from E.coli and Aquiflex aeolicus, than to DAHPS(Ec) and DAHPS(Sc) [4].
• Based on the precedent of the d-erythrose-4-phosphate (E4P) modeled in the active site of DAHPS, we have modeled PEP and A5P in KDOPS and compared the coordination of PEP and A5P in KDOPS with that of PEP and E4P in DAHPS [1].
• The formation of pyruvate and 2-PGA suggests that the reaction catalyzed by KDO8-P synthase may be initiated via a nucleophilic attack to PEP by a water molecule [5].
• The crystal structures of 3-deoxy-D-manno-2-octulosonate-8-phosphate synthase (KDOPS) from Escherichia coli complexed with the substrate phosphoenolpyruvate (PEP) and with a mechanism-based inhibitor (K(d) = 0.4 microM) were determined by molecular replacement using X-ray diffraction data to 2.8 and 2.3 A resolution, respectively [6].

Chemical compound and disease context of ECs1720

• The cDNA of kdsA could not complement Escherichia coli K-12 strain AB3257, which is defective in all three isoenzymes (AroFGH) of 3-deoxy-D-arabino-hept-2-ulosonate-7-phosphate (Dha-7-P) synthase (EC 4.1.2.15), and neither D-erythrose-4-phosphate nor D-ribose-5-phosphate could substitute for D-arabinose-5-phosphate in vitro [2].
• A Pseudomonas aeruginosa serotype O5 (PAO1) genomic DNA fragment that was able to complement a temperature-sensitive mutation in the 3-deoxy-D-manno-octulosonic acid (Kdo) 8-P synthase gene (kdsA) of Salmonella enterica serovar typhimurium was cloned [7].

Biological context of ECs1720

• The cDNA was confirmed by amplifying a 1,812-bp DNA fragment from the chromosome of pea that encoded four exons around the 5'-end of kdsA [2].
• Nucleotide sequence analysis revealed the presence of a potential operon with the gene order pyrG, kdsA, eno [7].
• An open reading frame, encoding for KDOPS (3-deoxy-D-manno-octulosonate 8-phosphate synthase), from Arabidopsis thaliana was cloned into a T7-driven expression vector [8].

Associations of ECs1720 with chemical compounds

• Treatment of the MMTS-inactivated KDO 8-P synthase with DTT resulted in restoration of enzymatic activity and the presence of two DTNB-titratable cysteine residues [9].
• Complete loss of KDO 8-P synthase activity correlates with the ethoxyformylation of three histidine residues by DEPC [10].
• Aquifex aeolicus 3-deoxy-D-manno-2-octulosonic acid 8-phosphate synthase: a new class of KDO 8-P synthase [11]?
• 3. KDO 8-P synthase activity is not restored to the DEPC-inactivated enzyme following treatment with hydroxylamine [10].
• Based on these observations and a report that KDO 8-P synthase is inactivated in a time-dependent manner with 3-bromopyruvate and that the substrate PEP protects against this inactivation, all four cysteines (38, 166, 206, and 249) were individually mutated to alanines via a modified PCR methodology [9].

Analytical, diagnostic and therapeutic context of ECs1720

• A simple one-step purification yields 200 mg of homogeneous KDO 8-P synthase per liter of cell culture [3].
• Circular dichroism measurements of wild-type KDO 8-P synthase and the four C --> A mutants indicate modest but significant changes in the structure of the mutants [9].
• Moreover, sequence alignments and phylogenetic analysis of KDO-8-P synthase protein sequences strongly suggested that there is a whole subfamily of KDO-8-P synthases that are also metalloenzymes [12].

References