The article reviews the enzymatic oxidation of methane by aerobic methanotrophs, focusing on the structure, function, and regulation of methane monoxygenase (MMO) enzymes. MMOs are complex enzymes that catalyze the direct oxidation of methane to methanol, a process crucial for the removal of methane from the atmosphere. The review highlights the importance of copper in the physiology of methanotrophs and the role of MMOs in this process. It discusses the structure and metal centers of particulate methane monoxygenase (pMMO), including the proposed active site and the metal binding sites in the PmoB and PmoC subunits. The article also explores the enzymatic activity of pMMO, the delivery of electrons, and the interaction with methanol dehydrogenase (MDH). Recent advances in structural biology, such as cryoelectron microscopy (cryoEM) and X-ray free electron laser (XFEL) crystallography, have provided new insights into the molecular mechanisms of MMOs. The review concludes by discussing the potential of engineered biological catalysis systems and bioinspired synthetic catalysts for applications in climate bioremediation and gas-to-liquid conversion processes.The article reviews the enzymatic oxidation of methane by aerobic methanotrophs, focusing on the structure, function, and regulation of methane monoxygenase (MMO) enzymes. MMOs are complex enzymes that catalyze the direct oxidation of methane to methanol, a process crucial for the removal of methane from the atmosphere. The review highlights the importance of copper in the physiology of methanotrophs and the role of MMOs in this process. It discusses the structure and metal centers of particulate methane monoxygenase (pMMO), including the proposed active site and the metal binding sites in the PmoB and PmoC subunits. The article also explores the enzymatic activity of pMMO, the delivery of electrons, and the interaction with methanol dehydrogenase (MDH). Recent advances in structural biology, such as cryoelectron microscopy (cryoEM) and X-ray free electron laser (XFEL) crystallography, have provided new insights into the molecular mechanisms of MMOs. The review concludes by discussing the potential of engineered biological catalysis systems and bioinspired synthetic catalysts for applications in climate bioremediation and gas-to-liquid conversion processes.