3NYE | pdb_00003nye

D-arginine dehydrogenase (DADH) is a flavin-dependent oxidoreductase. It is a member of the structural family consisting of D-amino acid oxidase, sarcosine oxidase, dimethyl glycine oxidase, and glycine oxidase. The enzyme has broad substrate specificity towards D-amino acids, particularly with cationic and hydrophobic D-amino acids. DADH and L-arginine dehydrogenase (LADH) make up a two-enzyme system involved in D- to L-arginine racemisation in pseudomonads and related species and both enzymes are products of the dauBAR operon, by D-arginine and D-lysine.

Crystallographic data shows that DADH from Pseudomonas aeruginosa (PaDADH) contains an active site loop L1 with two flexible segments that span the FAD-binding site and the substrate-binding site. It can occupy two distinct conformations, an open conformation competent for substrate binding and a closed conformation which is catalytically relevant and ligand-bound.