This enzyme, along with EC 2.7.1.170, anhydro-N-acetylmuramic acid kinase, is required for the utilization of anhydro-N-acetylmuramic acid in proteobacteria. The substrate is either imported from the medium or derived from the bacterium's own cell wall murein during cell wall recycling.
the reaction of Haemophilus influenzae MurQ hydrolase proceeds in the reverse direction, reaction mechanism, overview. A ring opening of MurNAc 6P, likely enzyme-catalyzed, first serves to generate the C1 aldehyde and consequently acidifies the hydrogen at the C2 position. This hydrogen is deprotonated by an active site acid/base residue (B1) to generate a resonance-stabilized enolate anion. The enolate then undergoes a syn elimination of D-lactate, aided by a catalytic acid/base residue (B2), to generate a DELTA2,3-unsaturated (E)-alkene intermediate. In a sequence that mirrors the elimination of lactate, B2 first serves to deprotonate an incoming water molecule for addition at the C3 position of the alkene intermediate to generate the enolate anion. This enolate is then protonated at the C2 position by B1 to generate the open chain form of GlcNAc 6P. Ring closure then generates the two anomers of the pyranose form of N-acetyl-D-glucosamine 6-phosphate
the reaction of Haemophilus influenzae MurQ hydrolase proceeds in the reverse direction, reaction mechanism, overview. A ring opening of MurNAc 6P, likely enzyme-catalyzed, first serves to generate the C1 aldehyde and consequently acidifies the hydrogen at the C2 position. This hydrogen is deprotonated by an active site acid/base residue (B1) to generate a resonance-stabilized enolate anion. The enolate then undergoes a syn elimination of D-lactate, aided by a catalytic acid/base residue (B2), to generate a DELTA2,3-unsaturated (E)-alkene intermediate. In a sequence that mirrors the elimination of lactate, B2 first serves to deprotonate an incoming water molecule for addition at the C3 position of the alkene intermediate to generate the enolate anion. This enolate is then protonated at the C2 position by B1 to generate the open chain form of GlcNAc 6P. Ring closure then generates the two anomers of the pyranose form of N-acetyl-D-glucosamine 6-phosphate
This enzyme, along with EC 2.7.1.170, anhydro-N-acetylmuramic acid kinase, is required for the utilization of anhydro-N-acetylmuramic acid in proteobacteria. The substrate is either imported from the medium or derived from the bacterium's own cell wall murein during cell wall recycling.
the etherase activity is assessed by utilizing N-acetylmuramate 6-phosphate as the substrate in a Morgan Elson reaction. This etherase-catalyzed reaction generates a chromogenic intermediate that can be detected by reacting with Ehrlich's reagent dimethylaminobenzaldehyde to yield a purple product. Also, radioactive assay with 32P-radiolabeled substrates N-acetyl-D-glucosamine 6-phosphate and N-acetylmuramate 6-phosphate
the etherase activity is assessed by utilizing N-acetylmuramate 6-phosphate as the substrate in a Morgan Elson reaction. This etherase-catalyzed reaction generates a chromogenic intermediate that can be detected by reacting with Ehrlich's reagent dimethylaminobenzaldehyde to yield a purple product. Also, radioactive assay with 32P-radiolabeled substrates N-acetyl-D-glucosamine 6-phosphate and N-acetylmuramate 6-phosphate
the etherase activity is assessed by utilizing N-acetylmuramate 6-phosphate as the substrate in a Morgan Elson reaction. This etherase-catalyzed reaction generates a chromogenic intermediate that can be detected by reacting with Ehrlich's reagent dimethylaminobenzaldehyde to yield a purple product. Also, radioactive assay with 32P-radiolabeled substrates N-acetyl-D-glucosamine 6-phosphate and N-acetylmuramate 6-phosphate
MurNAc utilization locus and MurNAc utilization pathway in Tannerella forsythia, overview. The three genes, Tanf_08375, Tanf_08380, and Tanf_08385 (murQ), encoding a MurNAc transporter, a putative sugar kinase, and a MurQ etherase, respectively, are transcriptionally linked. Enzymes MurT-MurK function as a PTS-independent MurNAc transporter
MurNAc utilization locus and MurNAc utilization pathway in Tannerella forsythia, overview. The three genes, Tanf_08375, Tanf_08380, and Tanf_08385 (murQ), encoding a MurNAc transporter, a putative sugar kinase, and a MurQ etherase, respectively, are transcriptionally linked. Enzymes MurT-MurK function as a PTS-independent MurNAc transporter
MurQ etherase, together with anhydro-N-acetylmuramic acid kinase, is required by Escherichia coli in order to metabolize anhydro-N-acetylmuramic acid obtained either from the environment or from its own cell wall
recycling of the cell wall-derived anhydroMurNAc depends on MurQ along with a bifunctional glycosidase/kinase (AnmK). MurQ, is essential for growth on N-acetylmuramate as the sole source of carbon and energy
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CRYSTALLIZATION (Commentary)
ORGANISM
UNIPROT
LITERATURE
purified recombinant enzyme as apoenzyme and in complex with inhibitor (2R)-2-[[(2R,3R,4R)-5-(acetylamino)-2,3,7-trihydroxy-1-(phosphonooxy)heptan-4-yl]oxy]propanoic acid, sitting drop vapor diffusion method, mixing of 8 mg/mL protein in 200 mM NaCl, 50 mM HEPES, and 5% glycerol with 0.2 M NaCl, 0.1 M Bis-Tris-HCl, pH 5.5, and 25% w/v PEG 3350 or with 0.17 M ammonium sulfate, 25.5% w/v PEG 4000, and 15% v/v glycerol, the former gives better results, soaking of crystals in solution containing the inhibitor, 25°C, X-ray diffraction structure determinnation and analysis at 2.6 A and 2.4 A resolution, respectively, molecular replacement using PDB entry 1NRI as the template
the mutant is essentially inactive, the mutant shows a very low, but measurable, level of activity with a kcat value that wis 10000fold lower than that of the wild type enzyme
gene murQ, DNA and amino acid sequence determination and analysis, genetic organization of the MurNAc utilization locus, the three genes, Tanf_08375, Tanf_08380, and Tanf_08385 (murQ), encoding a MurNAc transporter, a putative sugar kinase, and a MurQ etherase, respectively, are transcriptionally linked. Complementation with the Tanf_08375 and Tanf_08380 genes together in trans, but not individually, rescues the inability of an Escherichia coli mutant deficient in the phosphotransferase (PTS) system-dependent MurNAc transporter MurP as well as that of a double mutant deficient in MurP and components of the PTS system to grow on MurNAc. In addition, complementation with this two-gene construct in Escherichia coli causes depletion of MurNAc in the medium. Recombinant expression of His6-tagged enzyme in Escherichia coli strain BL21(DE3)
Uehara, T.; Suefuji, K.; Jaeger, T.; Mayer, C.; Park, J.T.
MurQ etherase is required by Escherichia coli in order to metabolize anhydro-N-acetylmuramic acid obtained either from the environment or from its own cell wall
4.2.1.126 N-acetylmuramic acid 6-phosphate etherase
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