Production of Dioxygen in the Dark: Dismutases of Oxyanions (Book chapter)
- DuBois, Jennifer L. [ Montana State University: Chemistry & Biochemistry ]
- Ojha, Sunil [ Montana State University: Chemistry & Biochemistry ]
O2-generating reactions are exceedingly rare in biology and difficult to mimic synthetically. Perchlorate-respiring bacteria enzymatically detoxify chlorite (ClO 2 −), the end product of the perchlorate (ClO 4 −) respiratory pathway, by rapidly converting it to dioxygen (O2) and chloride (Cl−). This reaction is catalyzed by a heme-containing protein, called chlorite dismutase (Cld), which bears no structural or sequence relationships with known peroxidases or other heme proteins and is part of a large family of proteins with more than one biochemical function. The original assumptions from the 1990s that perchlorate is not a natural product and that perchlorate respiration might be confined to a taxonomically narrow group of species have been called into question, as have the roles of perchlorate respiration and Cld-mediated reactions in the global biogeochemical cycle of chlorine. In this chapter, the chemistry and biochemistry of Cld-mediated O2 generation, as well as the biological and geochemical context of this extraordinary reaction, are described.