Iterative Combinatorial Mutagenesis as an Effective Strategy for Generation of Deacetoxycephalosporin C Synthase with Improved Activity toward Penicillin G

An iterative combinatorial mutagenesis (ICM) strategy was used to engineer deacetoxycephalosporin C synthase of Streptomyces clavuligerus (scDAOCS) for improved activity toward penicillin G. Seven mutational sites were repeatedly combined onto a starter mutant (C155Y Y184H V275I C281Y) of scDAOCS. Eleven improved combinatorial mutants were identified from 24 mutants in four rounds of ICM.