title: Atomic-resolution structure of an N5 flavin adduct in D-arginine dehydrogenase.
abstract: D-Arginine dehydrogenase (DADH) catalyzes the flavin-dependent oxidative deamination of D-arginine and other D-amino acids to the corresponding imino acids. The 1.07 Å atomic-resolution structure of DADH crystallized with D-leucine unexpectedly revealed a covalent N(5) flavin adduct, instead of the expected iminoleucine product in the active site. This acyl adduct has been successfully reproduced by photoreduction of DADH in the presence of 4-methyl-2-oxopentanoic acid (ketoleucine). The iminoleucine may be released readily because of weak interactions in the binding site, in contrast to iminoarginine, converted to ketoleucine, which reacts with activated FAD to form the covalently linked acyl adduct.
authors.affiliation: Department of Biology, Georgia State University, Atlanta, Georgia 30303, USA.
authors.forename: Guoxing
authors.initials: G
authors.lastname: Fu
authors.forename: Hongling
authors.initials: H
authors.lastname: Yuan
authors.forename: Siming
authors.initials: S
authors.lastname: Wang
authors.forename: Giovanni
authors.initials: G
authors.lastname: Gadda
authors.forename: Irene T
authors.initials: IT
authors.lastname: Weber
mesh_terms: D000594:Amino Acid Oxidoreductases / Q000737:chemistry*; D000693:Anaerobiosis / Q000528:radiation effects; D001120:Arginine / Q000737:chemistry; D020134:Catalytic Domain; D018360:Crystallography, X-Ray; D005415:Flavins / Q000737:chemistry*; D007651:Keto Acids / Q000737:chemistry; D008027:Light; D009584:Nitrogen / Q000737:chemistry*
chemical_list: D005415:Flavins; D007651:Keto Acids; C013082:alpha-ketoisocaproic acid; D001120:Arginine; D000594:Amino Acid Oxidoreductases; C040983:arginine oxidase; D009584:Nitrogen