Structural and biochemical characterisation of the N-Carbamoyl-β-Alanine Amidohydrolase from Rhizobium radiobacter MDC 8606

Abstract

N-Carbamoyl-β-Alanine Amidohydrolase (CβAA) constitute one of the most important groups of 26 industrially relevant enzymes used in production of optically pure amino acids and derivatives. In 27 this study, a N-carbamoyl-β-alanine amidohydrolase encoding gene from Rhizobium radiobacter 28 MDC 8606 was cloned and overexpressed in Escherichia coli. The purified recombinant enzyme 29 (RrCβAA) showed a specific activity of 14 U/mg using N-carbamoyl- β-alanine as a substrate with 30 an optimum activity of 55°C at pH 8.0. In this work, we report also the first prokaryotic N31 carbamoyl-β-alanine amidohydrolases structure at a resolution of 2.0 Å. A discontinuous catalytic 32 domain and a dimerization domain attached through a flexible hinge region at the domain interface 33 has been revealed. We have found that the ligand is interacting with a conserved glutamic acid 34 (Glu131), histidine (H385) and arginine (Arg291) residues