structural communications
S. thermophilum produces a haem-containing catalase with phenol oxidase activity which is involved in H2O2 degradation and the oxidation of some diphenolic compounds in the absence of H2O2. The dimensions or volume of the main channel are critical in determining the rate of both movement of H2O2 into the active site and dioxygen binding, as has previously been proposed for other monofunctional catalases.