Molecular cloning of the gene for edeine B1 amidinohydrolase in addition to the agmatinase activity in Bacillus subtilis.

A gene with a high-nucleotide sequence homology to the edeine B1 amidinohydrolase gene of Bacillus brevis was identified in the database of the Bacillus subtilis genome. The gene was isolated, expressed in Escherichia coli, and the gene product was analyzed with regard to the characteristics of its enzyme activity. A 32-kDa protein encoded by the ywhG gene showed a 69.8% amino acid sequence-homology to the edeine B1 amidinohydrolase of B. brevis. Among various guanidino-compounds, edeine B1 and agmatine were both efficiently hydrolyzed by the protein encoded by the ywhG gene, although edeine B1 was a more potent substrate than agmatine in this assay system. These data indicate that the protein encoded by the ywhG gene is an agmatinase that is essential for polyamine biosynthesis in B. subtilis.