Cloning, sequence analysis and expression of the gene encoding a novel wide-spectrum amidase belonging to the amidase signature superfamily fromAchromobacter xylosoxidans

Amidases are very important enzymes for industrial biocatalysis. We scored a novel amidase by screening the Achromobacter xylosoxidans gene library with cephalosporin analogous amides. The gene coding for the enzyme, designated ana, was cloned, sequenced and overexpressed in Escherichia coli. Sequence analysis of ana showed it to be an amidase signature family member. Interestingly, we noted that almost all Ana homologous amidases are from human pathogens responsible for chronic lung infections. Knowing the genetic context of Ana and its homologous amidases, we suggest that they could be a part of transposon structure. Ana can efficiently hydrolyze a series of cephalosporin analogous amides, including amides with an aninine, p-nitro-aninine, and beta-naphthylamine moiety, while cephalosporin could not serve as its substrate.