This enzyme, along with EC 4.2.1.126, N-acetylmuramic acid 6-phosphate etherase, 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 product N-acetylmuramate 6-phosphate is produced as a 7:1 mixture of the alpha- and beta-anomers.
ATP + 1,6-anhydro-N-acetyl-beta-muramate + H2O = ADP + N-acetylmuramate 6-phosphate
reaction mechanism, structure-function analysis, overview. A one-step catalytic mechanism is proposed that involves attack of water at the anomeric center leading to cleavage of the 1,6-anhydro ring and phosphoryl transfer. The reaction inverts the anomeric center of MurNAc. Transient formation of an intermediate (MurNAc) in a two-step mechanism may also be possible. It is also possible that the gamma-phosphate leaves the ATP as a transient metaphosphate prior to the anhydro-bond cleavage
ATP + 1,6-anhydro-N-acetyl-beta-muramate + H2O = ADP + N-acetylmuramate 6-phosphate
the oxygen of 1,6-anhydro-N-acetyl-beta-muramate, that is to be phosphorylated, is trapped in the anhydro ring structure and must first be cleaved prior to phosphorylation. In order to do this, Asp182 is predicted to act as a base to deprotonate a water molecule and enhance its nucleophilicity. The water would then attack the anomeric carbon of the sugar concomitant with transfer of the gamma-phosphate of ATP. The lone pair electrons from the O5 position would assume partial double-bond characteristics and stabilize the oxocarbenium ion that would otherwise develop, with the anomeric carbon adopting an axial conformation in the product acetylmuramate 6-phosphate, catalytic role of the conserved residue Asp182 residue in catalysis
This enzyme, along with EC 4.2.1.126, N-acetylmuramic acid 6-phosphate etherase, 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 product N-acetylmuramate 6-phosphate is produced as a 7:1 mixture of the alpha- and beta-anomers.
1,6-anhydro-N-acetyl-beta-muramate is a breakdown product of bacterial peptidoglycan in many Gram-negative bacteria, it is released from murein tripeptide
1,6-anhydro-N-acetyl-beta-muramate is a breakdown product of bacterial peptidoglycan in many Gram-negative bacteria, it is released from murein tripeptide
the enzyme utilizes an unusual mechanism whereby the sugar substrate is both cleaved and phosphorylated. N-acetylmuramate cannot be used as a substrate for AnmK
the enzyme utilizes an unusual mechanism whereby the sugar substrate is both cleaved and phosphorylated. N-acetylmuramate cannot be used as a substrate for AnmK
1,6-anhydro-N-acetyl-beta-muramate is a breakdown product of bacterial peptidoglycan in many Gram-negative bacteria, it is released from murein tripeptide
1,6-anhydro-N-acetyl-beta-muramate is a breakdown product of bacterial peptidoglycan in many Gram-negative bacteria, it is released from murein tripeptide
enzyme AnmK adopts an open conformation in solution in the absence of ligand and that it remains in this open state after binding nonhydrolyzable ATP analogue adenosine 5'-(beta,gamma-methylene)triphosphate (AMPPCP)
enzyme AnmK adopts an open conformation in solution in the absence of ligand and that it remains in this open state after binding nonhydrolyzable ATP analogue adenosine 5'-(beta,gamma-methylene)triphosphate (AMPPCP)
1,6-anhydro-N-acetylmuramic acid is produced during peptidoglucan degeneration by transglycosylases, e.g. AmpD or NagZ. The AnmK reaction product N-acetylmuramate 6-phosphate returns into peptidoglycan recycling
1,6-anhydro-N-acetylmuramic acid kinase (AnmK) and levoglucosan kinase (LGK) share significant sequence homology (30-40%) and form a subfamily of anhydrosugar kinases in the sugar kinase family, which is itself part of a larger superfamily of ATPase domain containing proteins (sugar kinase/heat shock protein 70/actin superfamily) that contain conserved structural motifs including the ATP binding domain and an interdomain hinge region that allows the two major domains to rotate relative to each other
1,6-anhydro-N-acetylmuramic acid kinase (AnmK) and levoglucosan kinase (LGK) share significant sequence homology (30-40%) and form a subfamily of anhydrosugar kinases in the sugar kinase family, which is itself part of a larger superfamily of ATPase domain containing proteins (sugar kinase/heat shock protein 70/actin superfamily) that contain conserved structural motifs including the ATP binding domain and an interdomain hinge region that allows the two major domains to rotate relative to each other
althoughAnmKadopts a two-domain fold that is structurally similar to proteins of the hexokinase-hsp70-actin superfamily, 1,6-anhydrosugar kinases are mechanistically unique in that they catalyze both the hydrolysis of the 1,6-anhydro ring and the transfer of the gamma-phosphate group from ATP to O6 of sugar substrates
phylogenetic analysis and comparison of 1,6-anhydro-N-acetylmuramic acid kinase with levoglucan kinase and AnmK-like enzymes, molecular docking, dynamics simulation, and homology modelling, overview. AnmK and LGK are conserved proteins, and 187Asp, 212Asp are enzymatic residues, respectively
phylogenetic analysis and comparison of 1,6-anhydro-N-acetylmuramic acid kinase with levoglucan kinase and AnmK-like enzymes, molecular docking, dynamics simulation, and homology modelling, overview. AnmK and LGK are conserved proteins, and 187Asp, 212Asp are enzymatic residues, respectively
phylogenetic analysis and comparison of 1,6-anhydro-N-acetylmuramic acid kinase with levoglucan kinase and AnmK-like enzymes, molecular docking, dynamics simulation, and homology modelling, overview. AnmK and LGK are conserved proteins, and 187Asp, 212Asp are enzymatic residues, respectively
MurQ and AnmK kinase are required for utilization of 1,6-anhydro-N-acetyl-beta-muramate derived either from cell wall murein or imported from the medium
analysis of structures of enzyme AnmK bound to the reaction product ADP and the substrate anhMurNAc as well as the positioning of a conserved aspartate residue (Asp182) in the active site, prediction of a mechanism of catalysis for this enzyme. Conformational dynamics of AnmK during its catalytic cycle from subsequent structural studies of AnmK in the open conformation as well as small-angle X-ray scattering analysis of the enzyme. In solution the enzyme may adopt an open conformation when bound to either AMPPCP or without nucleotide present, while it adopts a more compact globular conformation in the presence of ADP, suggestive of a closed state. Dramatic conformational dynamics for AnmK, whereby it cycles between a closed catalytically competent state and an open state that likely facilitates substrate binding and product departure
the peptidoglycan recycling enzyme 1,6-anhydro-N-acetylmuramic acid kinase from Pseudomonas aeruginosa undergoes large conformational changes during its catalytic cycle, with its two domains rotating apart by up to 32° around two hinge regions to expose an active site cleft into which the substrates 1,6-anhydroMurNAc and ATP can bind. Ligand binding at the active site of AnmK coordinates its conformational itinerary
the peptidoglycan recycling enzyme 1,6-anhydro-N-acetylmuramic acid kinase from Pseudomonas aeruginosa undergoes large conformational changes during its catalytic cycle, with its two domains rotating apart by up to 32° around two hinge regions to expose an active site cleft into which the substrates 1,6-anhydroMurNAc and ATP can bind. Ligand binding at the active site of AnmK coordinates its conformational itinerary
the enzyme structure exhibits two major domains separated by a deep hinge region with the nucleotide and sugar binding near the hinge. The protein forms a dimer, with extensive interactions between the two monomers
AnmK in complex with 1,6-anhydro-N-acetylmuramic acid and ADP, hanging drop vapor diffusion method, using 25% (w/v) polyethylene glycol 4000, 0.2 M (NH4)2SO4, and 0.1 M tri-sodium citrate (pH 5.6)
purified recombinant enzyme bound to a nonhydrolyzable ATP analogue (AMPPCP) and 1,6-anhydroMurNAc, hanging drop vapor diffusion method, for enzyme AnmK bound to AMPPCP, 6.5 mg/ml protein in 600 mM NaCl, 2 mM AMPPCP, 4 mM MgCl2, 0.5 mM TCEP, and 20 mM Tris, pH 8.0, is mixed with an equal volume of mother liquor containing 26% PEG 4000, 0.2 M MgCl2, 0.1 M Tris, pH 9.0, for enzyme AnmK bound to AMPPCP and the anhMurNAc sugar, AnmK s first co-crystallized with AMPPCP by mixing equal volumes of mother liquor containing 24% PEG 4000, 0.2 M MgCl2, 0.1 M Tris, pH 8.2, with the enzyme at 6.5 mg/ml in 600 mM NaCl, 2 mM AMPPCP, 4 mM MgCl2, 0.5 mM TCEP, 20 mM Tris, pH 8.0, a single crystal of the AnmK-AMPPCP complex is then transferred to a drop of reservoir buffer supplemented with 8 mM anhMurNAc, 2 mM AMPPCP, and 4 mM MgCl2 and soaked for 1 h, at room temperature, X-ray diffraction structure determination and analysis at 1.67-1.84 A resolution
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