标题：Gene Identification and Characterization of the Pyridoxine Degradative Enzyme α-(N-Acetylaminomethylene)succinic Acid Amidohydrolase from Mesorhizobium loti MAFF303099
期刊名称：Journal of Nutritional Science and Vitaminology
印刷版ISSN：0301-4800
电子版ISSN：1881-7742
出版年度：2008
卷号：54
期号：3
页码：185-190
DOI：10.3177/jnsv.54.185
出版社：Center for Academic Publications Japan
摘要：We have found for the first time that a chromosomal gene, mlr6787, in Mesorhizobium loti encodes the pyridoxine degradative enzyme α-( N -acetylaminomethylene)succinic acid (AAMS) amidohydrolase. The recombinant enzyme expressed in Escherichia coli cells was homogeneously purified and characterized. The enzyme consisted of two subunits each with a molecular mass of 34,000±1,000 Da, and exhibited Km and kcat values of 53.7±6 μ M and 307.3±12 min−1, respectively. The enzyme required no cofactor or metal ion. The primary structure of AAMS amidohydrolase was elucidated for the first time here. The primary structure of the enzyme protein showed no significant identity to those of known hydrolase proteins and low homology to those of fluoroacetate dehalogenase (PDB code, 1Y37), haloalkane dehalogenase (1K5P), and aryl esterase (1VA4).
