Production of NO from arginine and molecular oxygen is a complex chemical reaction
unique to biology. Our understanding of the chemical and regulation mechanisms of the NO
synthases has developed over the past two decades, uncovering some extraordinary
features. This article reviews recent progress and highlights current issues and
controversies. The structure of the enzyme has now been determined almost in entirety,
although it is as a selection of fragments, which are difficult to assemble unambiguously. NO …