Enhancing the peroxidatic activity of KatG by deletion mutagenesis

► Catalase-negative KatGs were made by Y226F exchange and LL1 deletion and compared. ► Deletion produced up to ten-fold greater peroxidase activity than substitution. ► Deletion variants were also much less sensitive to H2O2-dependent inactivation. ► Both types of variants showed similar kinetics of compound I, II, and III formation. ► Deletion gave 60 fold more rapid ferryl intermediate reduction by electron donors.