PROSTAGLANDIN-H SYNTHASE

The prostaglandin H synthase structure reveals that the enzyme has a f old similar to those of other heme peroxidases, but differing in that a second active site has evolved within this fold which catalyzes the cyclooxygenase reaction. The protein has also acquired two additional domains: a membrane-binding motif that lacks transmembrane segments, m ediating attachment to the membrane via helices that lie parallel to t he membrane, and an epidermal growth factor-like module found just bef ore the membrane-binding motif. The epidermal growth factor-like modul e is located in the dimer interface.