Haliscomenobacter hydrossis D-amino acid transaminase (Halhy)

Haliscomenobacter hydrossis D-amino acid transaminase (Halhy) is a pyridoxal-5'-phosphate (PLP)-dependent enzyme belonging to the fold type IV transaminase superfamily. It catalyzes the reversible stereoselective transfer of an amino group from a D-amino acid to an α-keto acid, producing a new D-amino acid and its corresponding keto acid. In bacteria, D-amino acid transaminases (DAATs) are essential for the synthesis of D-glutamate, a critical component of the peptidoglycan layer in the cell wall. Halhy is particularly distinguished by its high catalytic efficiency and a unique active site architecture featuring three arginine residues that facilitate substrate binding. While DAATs are considered potential targets for the development of novel antibacterial agents due to their absence in humans, Halhy is currently primarily utilized as a robust biocatalyst in the pharmaceutical industry for the asymmetric synthesis of enantiomerically pure D-amino acids. These D-amino acids serve as vital building blocks for various bioactive compounds and drugs. The enzyme demonstrates strict stereoselectivity, ensuring that no L-amino acid products are formed during the reaction.

Other names

D-amino acid transaminaseD-amino acid aminotransferaseDAATDATATA_Halhy

Inhibition of D-amino acid transaminase activity, leading to the depletion of D-glutamate and D-alanine required for bacterial cell wall peptidoglycan synthesis.