2.02012-05-31 14:48:38 -06002015-06-03 17:20:08 -0600ECMDB20518M2MDB001326N-Acetylmuramate 6-phosphateMurNAC-6-P is a member of the chemical class known as Sugar Acids and Derivatives. These are compounds containing a saccharide unit which bears a carboxylic acid group. It is a substrate for N-acetylmuramate-6-phosphate etherase. This enzyme catalyzes the cleavage of the D-lactyl ether of MurNAC-6-P to produce GlcNAC-6-P and D lactate. It is required for growth on MurNAC and plays a role in cell wall biogenesis and peptidoglycan recylcing.MurNAc-6-PN-Acetylmuramate 6-phosphateN-Acetylmuramic acid 6-phosphateN-Acetylmuramic acid 6-phosphoric acidC11H19NO11P372.2424372.0695719672-{[(3R,4R,5S,6R)-2,5-dihydroxy-3-[(1-oxidoethylidene)azaniumyl]-6-[(phosphono-λ³-oxidanyliumyl)methyl]oxan-4-yl]oxy}propanoate2-{[(3R,4R,5S,6R)-2,5-dihydroxy-3-[(1-oxidoethylidene)ammonio]-6-[(phosphono-λ³-oxidanyliumyl)methyl]oxan-4-yl]oxy}propanoate[H]C(C)(O[C@@]1([H])[C@]([H])(O)[C@@]([H])(C[O+]P(O)(O)=O)OC([H])(O)[C@]1([H])[NH+]=C(C)[O-])C([O-])=OInChI=1S/C11H20NO11P/c1-4(10(15)16)22-9-7(12-5(2)13)11(17)23-6(8(9)14)3-21-24(18,19)20/h4,6-9,11,14,17H,3H2,1-2H3,(H,12,13)(H,15,16)(H2,18,19,20)/q+1/p-1/t4?,6-,7-,8-,9-,11?/m1/s1METUMBUEJVSNMZ-NFSFVEDMSA-MCytoplasmPeriplasmlogp0.77logs-1.68solubility9.93e+00 g/llogp-5.5pka_strongest_acidic-7.7pka_strongest_basic1.46iupac2-{[(3R,4R,5S,6R)-2,5-dihydroxy-3-[(1-oxidoethylidene)azaniumyl]-6-[(phosphono-λ³-oxidanyliumyl)methyl]oxan-4-yl]oxy}propanoateaverage_mass372.2424mono_mass372.069571967smiles[H]C(C)(O[C@@]1([H])[C@]([H])(O)[C@@]([H])(C[O+]P(O)(O)=O)OC([H])(O)[C@]1([H])[NH+]=C(C)[O-])C([O-])=OformulaC11H19NO11PinchiInChI=1S/C11H20NO11P/c1-4(10(15)16)22-9-7(12-5(2)13)11(17)23-6(8(9)14)3-21-24(18,19)20/h4,6-9,11,14,17H,3H2,1-2H3,(H,12,13)(H,15,16)(H2,18,19,20)/q+1/p-1/t4?,6-,7-,8-,9-,11?/m1/s1inchikeyMETUMBUEJVSNMZ-NFSFVEDMSA-Mpolar_surface_area202.84refractivity106.35polarizability31.49rotatable_bond_count7acceptor_count11donor_count5physiological_charge-2formal_charge01,6-anhydro-<i>N</i>-acetylmuramic acid recyclingAnhydromuropeptides (mainly GlcNAc-1,6-anhMurNAc-L-Ala-γ-D-Glu-DAP-D-Ala) are steadily released during growth by lytic transglycosylases and endopeptidases and imported back into the cytoplasm for recycling. During bacterial growth, a very large proportion of the peptidoglycan polymer is degraded and reused in a process termed cell wall recycling. For example, the Gram-negative bacterium Escherichia coli recovers about half of its cell wall within one generation.
The anhydromuropeptides are imported by the ampG-encoded muropeptide:H+ symporter. Once inside the cytoplasm, the anhydromuropeptides are hydrolyzed by N-acetylmuramoyl-L-alanine amidase (ampD), β-N-acetylhexosaminidase (nagZ) and L,D-carboxypeptidase A (ldcA), yielding N-acetyl-β-D-glucosamine, 1,6-anhydro-N-acetyl-β-muramate, L-alanyl-γ-D-glutamyl-meso-diaminopimelate and D-alanine.
1,6-anhydro-N-acetyl-β-muramate is phosphorylated by anhydro-N-acetylmuramic acid kinase (anmK) and then converted into N-acetyl-D-glucosamine 6-phosphate by N-acetylmuramic acid 6-phosphate etherase (murQ). This is a branch point, as this compound could be directed either for further degradation or for recycling into new peptidoglycan monomers, as described in this pathway. The final product of this pathway, UDP-N-acetyl-α-D-muramate, is one of the precursors for peptidoglycan biosynthesis.
The tripeptide L-alanyl-γ-D-glutamyl-meso-diaminopimelate, which is generated by muramoyltetrapeptide carboxypeptidase, can be degraded further, as described in muropeptide degradation. However, the vast majority is recycled by muropeptide ligase (mpl). This enzyme is a dedicated recycling enzyme that attaches the recovered Ala-Glu-DAP tripeptide to UDP-N-acetyl-α-D-muramate, thereby substituting three amino acid ligases of the peptidoglycan de novobiosynthetic pathway.
Although exogenously provided 1,6-anhydro-N-acetyl-β-muramate can be taken up by Escherichia coli, it can not serve as the sole source of carbon for growth, suggesting that it may be toxic to the cell. (EcoCyc)
PW002064Metabolic1,6-anhydro-<i>N</i>-acetylmuramic acid recyclingPWY0-1261Specdb::NmrOneD285289Specdb::NmrOneD285290Specdb::NmrOneD285291Specdb::NmrOneD285292Specdb::NmrOneD285293Specdb::NmrOneD285294Specdb::NmrOneD285295Specdb::NmrOneD285296Specdb::NmrOneD285297Specdb::NmrOneD285298Specdb::NmrOneD285299Specdb::NmrOneD285300Specdb::NmrOneD285301Specdb::NmrOneD285302Specdb::NmrOneD285303Specdb::NmrOneD285304Specdb::NmrOneD285305Specdb::NmrOneD285306Specdb::NmrOneD285307Specdb::NmrOneD285308Specdb::MsMs1287742Specdb::MsMs1287743Specdb::MsMs1287744Specdb::MsMs1402519Specdb::MsMs1402520Specdb::MsMs14025212520291147968CPD0-881Keseler, I. M., Collado-Vides, J., Santos-Zavaleta, A., Peralta-Gil, M., Gama-Castro, S., Muniz-Rascado, L., Bonavides-Martinez, C., Paley, S., Krummenacker, M., Altman, T., Kaipa, P., Spaulding, A., Pacheco, J., Latendresse, M., Fulcher, C., Sarker, M., Shearer, A. G., Mackie, A., Paulsen, I., Gunsalus, R. P., Karp, P. D. (2011). "EcoCyc: a comprehensive database of Escherichia coli biology." Nucleic Acids Res 39:D583-D590.21097882N-acetylmuramic acid 6-phosphate etheraseP76535MURQ_ECOLImurQhttp://ecmdb.ca/proteins/P76535.xmlAnhydro-N-acetylmuramic acid kinaseP77570ANMK_ECOLIanmKhttp://ecmdb.ca/proteins/P77570.xmlN-Acetylmuramate 6-phosphate + Water <> N-Acetyl-D-Glucosamine 6-Phosphate + D-Lactic acidPW_R006028anhydro-n-acetylmuramic acid + Adenosine triphosphate + Water > N-Acetylmuramate 6-phosphate + ADP + Hydrogen ionPW_R006027