Decomposes hydrogen peroxide into water and oxygen; serves to protect cells from the toxic effects of hydrogen peroxide. 2 H2O2 = 2 H2O + O2 By peroxide and bfr-bound iron. Heteromultimer. Possibly an alpha(2)beta-heterotrimer where the alpha subunit is a 56 kDa protein and the beta subunit a 45 kDa protein. Belongs to the catalase family.