Ligases;
Forming carbon-nitrogen bonds;
Acid-D-ammonia (or amine) ligases (amide synthases)
BRITE hierarchy

D-aspartate:[beta-GlcNAc-(1->4)-Mur2Ac(oyl-L-Ala-gamma-D-Glu-L-Lys-D-Ala-D-Ala)]n ligase (ADP-forming)

ATP + D-aspartate + [beta-GlcNAc-(1->4)-Mur2Ac(oyl-L-Ala-gamma-D-Glu-L-Lys-D-Ala-D-Ala)]n = [beta-GlcNAc-(1->4)-Mur2Ac(oyl-L-Ala-gamma-D-Glu-6-N-(beta-D-Asp)-L-Lys-D-Ala-D-Ala)]n + ADP + phosphate [RN:R09590]

R09590
Reaction

ATP [CPD:C00002];
D-aspartate [CPD:C00402];
[beta-GlcNAc-(1->4)-Mur2Ac(oyl-L-Ala-gamma-D-Glu-L-Lys-D-Ala-D-Ala)]n [CPD:C19695]

This enzyme forms part of the peptidoglycan assembly pathway of Gram-positive bacteria grown in medium containing D-Asp. Normally, the side chains the acylate the 6-amino group of the L-lysine residue contain L-Ala-L-Ala but these amino acids are replaced by D-Asp when D-Asp is included in the medium. Hybrid chains containing L-Ala-D-Asp, L-Ala-L-Ala-D-Asp or D-Asp-L-Ala are not formed [4]. The enzyme belongs in the ATP-grasp protein superfamily [3,4]. The enzyme is highly specific for D-aspartate, as L-aspartate, D-glutamate, D-alanine, D-iso-asparagine and D-malic acid are not substrates [4]. In Enterococcus faecium, the substrate D-aspartate is produced by EC 5.1.1.13, aspartate racemase [4]

EC 6.3.1.12 created 2006

1  [PMID:4262567]

2  [PMID:4626717]

3  [PMID:9416615]

4  [PMID:16510449]