Literature summary for 4.2.1.126 extracted from

Hadi, T.; Hazra, S.; Tanner, M.E.; Blanchard, J.S.
Structure of MurNAc 6-phosphate hydrolase (MurQ) from Haemophilus influenzae with a bound inhibitor (2013), Biochemistry, 52, 9358-9366.

Search for more literature for 4.2.1.126

Cloned(Commentary)

Cloned (Comment)	Organism
gene MurQ-HI, functional expression of N-terminally His6-tagged enzyme in Escherichia coli	Haemophilus influenzae

Crystallization (Commentary)

Crystallization (Comment)	Organism
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	Haemophilus influenzae

Crystallization (Comment)

Organism

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

Haemophilus influenzae

Inhibitors

Inhibitors	Comment	Organism	Structure
(2R)-2-[[(2R,3R,4R)-5-(acetylamino)-2,3,7-trihydroxy-1-(phosphonooxy)heptan-4-yl]oxy]propanoic acid	a N-acetylmuramate 6-phosphate open chain analogue, competitive inhibition	Haemophilus influenzae
(2R,3S,4R)-5-(acetylamino)-2,3,4,7-tetrahydroxyheptyl phosphate	a N-acetyl-D-glucosamine 6-phosphate open chain analogue, competitive inhibition	Haemophilus influenzae

Natural Substrates/ Products (Substrates)

Natural Substrates	Organism	Comment (Nat. Sub.)	Natural Products	Comment (Nat. Pro.)	Rev.	Reac.
N-acetylmuramate 6-phosphate + H2O	Haemophilus influenzae	-	(R)-lactate + N-acetyl-D-glucosamine 6-phosphate	-	?
N-acetylmuramate 6-phosphate + H2O	Haemophilus influenzae KW20	-	(R)-lactate + N-acetyl-D-glucosamine 6-phosphate	-	?

Organism

Organism	UniProt	Comment	Textmining
Haemophilus influenzae	P44862	gene MurQ-HI	-
Haemophilus influenzae KW20	P44862	gene MurQ-HI	-

Purification (Commentary)

Purification (Comment)	Organism
recombinant N-terminally His6-tagged enzyme from Escherichia coli by nickel affinity chromatography	Haemophilus influenzae

Reaction

Reaction	Comment	Organism	Reaction ID
(R)-lactate + N-acetyl-D-glucosamine 6-phosphate = N-acetylmuramate 6-phosphate + H2O	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	Haemophilus influenzae	a

Substrates and Products (Substrate)

Substrates	Comment Substrates	Organism	Products	Comment (Products)	Rev.
N-acetylmuramate 6-phosphate + H2O	-	Haemophilus influenzae	(R)-lactate + N-acetyl-D-glucosamine 6-phosphate	-	?
N-acetylmuramate 6-phosphate + H2O	the MurQ hydrolase catalyzes the cleavage of a nonlabile ether bond at the C3 position of N-acetylmuramate 6-phosphate	Haemophilus influenzae	(R)-lactate + N-acetyl-D-glucosamine 6-phosphate	-	?
N-acetylmuramate 6-phosphate + H2O	-	Haemophilus influenzae KW20	(R)-lactate + N-acetyl-D-glucosamine 6-phosphate	-	?
N-acetylmuramate 6-phosphate + H2O	the MurQ hydrolase catalyzes the cleavage of a nonlabile ether bond at the C3 position of N-acetylmuramate 6-phosphate	Haemophilus influenzae KW20	(R)-lactate + N-acetyl-D-glucosamine 6-phosphate	-	?

Synonyms

Synonyms	Comment	Organism
MurQ	-	Haemophilus influenzae
MurQ hydrolase	-	Haemophilus influenzae

Temperature Optimum [°C]

Temperature Optimum [°C]	Temperature Optimum Maximum [°C]	Comment	Organism
30	-	assay at	Haemophilus influenzae

pH Optimum

pH Optimum Minimum	pH Optimum Maximum	Comment	Organism
8	-	assay at	Haemophilus influenzae

Ki Value [mM]

Ki Value [mM]	Ki Value maximum [mM]	Inhibitor	Comment	Organism	Structure
0.23	-	(2R)-2-[[(2R,3R,4R)-5-(acetylamino)-2,3,7-trihydroxy-1-(phosphonooxy)heptan-4-yl]oxy]propanoic acid	pH 8.0, 30°C	Haemophilus influenzae
1.1	-	(2R,3S,4R)-5-(acetylamino)-2,3,4,7-tetrahydroxyheptyl phosphate	pH 8.0, 30°C	Haemophilus influenzae