Two amino acid amidohydrolase genes encoding L-stereospecific carbamoylase and aminoacylase are organized in a common operon in Bacillus stearothermophilus

Abstract

The L-carbamoylase gene (amaB) upstream of the previously detected L- aminoacylase gene (amaA) in the Bacillus stearothermophilus NCIB8224 strain was identified in this study. The amaB and amaA genes are cotranscribed as a single mRNA from the same transcriptional start. The two-ama-gene operon is conserved in B. stearothermophilus strains. A cross-activity of L- carbamoylase towards respective substrates for L-amino-acylase supports the hypothesis of a common ancestor for both amino acid amidohydrolase genes.