N-carbamyl-D-amino acid amidohydrolase (DCase, class 6 nitrilases)
DCase hydrolyses N-carbamyl-D-amino acids to produce D-amino acids. It is an important biocatalyst in the pharmaceutical industry, producing useful D-amino acids for example in the preparation of beta-lactam antibiotics. This subgroup belongs to a larger nitrilase superfamily comprised of nitrile- or amide-hydrolyzing enzymes and amide-condensing enzymes, which depend on a Glu-Lys-Cys catalytic triad. This superfamily has been classified in the literature based on global and structure based sequence analysis into thirteen different enzyme classes (referred to as 1-13), this subgroup corresponds to class 6. Members of this superfamily generally form homomeric complexes, the basic building block of which is a homodimer. Agrobacterium radiobacter DCase forms a tetramer (dimer of dimers). Some DCases may form trimers.
Structure:1UF8_A, Agrobacterium sp., DCase (C171aV236A mutant) dimer bound with N-carbamyl-D-phenylalanine; contacts defined at 4A. - View structure with Cn3D
Comment:Agrobacterium radiobacter DCase is a tetramer (dimer of dimers) having four active sites, two per dimer. All but one of the active site residues comes from one of the two participating monomers; the remaining residue comes from the it#s partner monomer.