... Taiwan;3Department of Pharmacy and Pharmacology, The University of Bath, UK Deacetoxycephalosporin C synthase (DAOCS) catalyses the oxidative ring expansion of penicillin N, the committed step in the biosynthesis ... type of mutant,represented by arginines 306 and 307, are located in the C- terminus. They appear to modulate the activity of the C- terminus, which encloses the DAOCS active site during catalysis ... The role of arginine residues in substrate binding and catalysis by deacetoxycephalosporin C synthase Sarah J. Lipscomb1,*, Hwei-Jen Lee1,2,*, Mridul Mukherji1, Jack E. Baldwin1, Christopher...