One is Lonely and Three is a Crowd: Two Coppers Are for Methane Oxidation

What/where is the active site? The determination of the metal ion content and makeup of the bacterial membrane protein methane monooxygenase (pMMO) has an enigmatic research history, despite protein X‐ray structures. A new study appears to settle the issue; the dicopper center facilitates oxidation of methane to methanol. However, the unusual active‐site environment leaves many questions for future investigations on the relevant copper‐dioxygen chemistry and biochemistry.