Role of proximal methionine residues in Leishmania major peroxidase

► Leishmania major peroxidase is structurally hybrid enzyme of ascorbate peroxidase and cytochrome c peroxidase. ► We analyzed the function of proximal methionine residues in this protein. ► The catalytic efficiency of cytochrome c oxidation in mutant was decreased by about 50 times. ► We propose the proximal methionine residues in this protein are an important in the ferrocytochrome c oxidation.