In enzymology, a D-alanineâÂÂD-alanine ligase () is an enzyme that catalyzes the chemical reaction
Thus, the two substrates of this enzyme are ATP and D-alanine, whereas its 3 products are ADP, phosphate, and D-alanyl-D-alanine.
This enzyme belongs to the family of ATP-grasp ligases, specifically those forming carbon-nitrogen bonds as acid-D-amino-acid ligases (peptide synthases). The systematic name of this enzyme class is D-alanine:D-alanine ligase (ADP-forming). Other names in common use include alanine:alanine ligase (ADP-forming), and alanylalanine synthetase. This enzyme participates in d-alanine metabolism and peptidoglycan biosynthesis. Phosphinate and D-cycloserine are known to inhibit this enzyme.
The N-terminal region of the D-alanineâÂÂD-alanine ligase is thought to be involved in substrate binding, while the C-terminus is thought to be a catalytic domain.
As of late 2007, 8 structures have been solved for this class of enzymes, with PDB accession codes , , , , , , and .