The aspartyl residue at position 433 of gamma-glutamyltranspeptidase of Escherichia coli K-12 was replaced by an asparaginyl residue. This substitution enabled gamma-glutamyltranspeptidase to deacylate glutaryl-7-aminocephalosporanic acid, producing 7-aminocephalosporanic acid, which is a starting material for the synthesis of semisynthetic cephalosporins.
A single amino acid substitution converts gamma-glutamyltranspeptidase to a class IV cephalosporin acylase (glutaryl-7-aminocephalosporanic acid acylase).
Division of Integrated Life Science, Graduate School of Biostudies, Kyoto University, Oiwake-cho, Kitashirakawa, Sakyo-ku, Kyoto 606-8502, Japan. hideyuki@lif.kyoto-u.ac.jp.
