UDP-N-acetylmuramoyl-tripeptide—D-alanyl-D-alanine ligase

In enzymology, an UDP-N-acetylmuramoyl-tripeptide-D-alanyl-D-alanine ligase (EC 6.3.2.10) is an enzyme that catalyzes the chemical reaction

ATP + UDP-N-acetylmuramoyl-L-alanyl-gamma-D-glutamyl-L-lysine + D-alanyl-D-alanine ADP + phosphate + UDP-N-acetylmuramoyl-L-alanyl-gamma-D-glutamyl-L-lysyl-D-alanyl-D- alanine

The 3 substrates of this enzyme are ATP, UDP-N-acetylmuramoyl-L-alanyl-gamma-D-glutamyl-L-lysine, and D-alanyl-D-alanine, whereas its 4 products are ADP, phosphate, UDP-N-acetylmuramoyl-L-alanyl-gamma-D-glutamyl-L-lysyl-D-alanyl-D-, and alanine.

This enzyme belongs to the family of ligases, specifically those forming carbon-nitrogen bonds as acid-D-amino-acid ligases (peptide synthases). The systematic name of this enzyme class is UDP-N-acetylmuramoyl-L-alanyl-D-glutamyl-L-lysine:D-alanyl-D-alanine ligase (ADP-forming). Other names in common use include MurF synthetase, UDP-N-acetylmuramoyl-L-alanyl-D-glutamyl-L-lysyl-D-alanyl-D-alanine, synthetase, UDP-N-acetylmuramoylalanyl-D-glutamyl-lysine-D-alanyl-D-alanine, ligase, uridine diphosphoacetylmuramoylpentapeptide synthetase, UDPacetylmuramoylpentapeptide synthetase, and UDP-MurNAc-L-Ala-D-Glu-L-Lys:D-Ala-D-Ala ligase. This enzyme participates in lysine biosynthesis and peptidoglycan biosynthesis.

Structural studies

As of late 2007, two structures have been solved for this class of enzymes, with PDB accession codes 2AM1 and 2AM2.

References

• Ito, E and Strominger JL (1962). "Enzymatic synthesis of the peptide in bacterial uridine nucleotides II. Enzymatic synthesis and addition of D-alanyl-D-alanine". J. Biol. Chem. 237: 2696–2703. 
• van Heijenoort J (2001). "Recent advances in the formation of the bacterial peptidoglycan monomer unit". Nat. Prod. Rep. 18 (5): 503–19. doi:10.1039/a804532a. PMID 11699883.