Research group Pia Ädelroth's research group

Bacterial respiration

In cellular respiration, reduction of a terminal electron acceptor is linked to the production of a transmembrane proton gradient, essential for the survival of the organism. The terminal electron acceptor oxygen is, in our own mitochondria, reduced by the proton-pumping enzyme cytochrome c oxidase, which belongs to the superfamily of heme-copper oxidases (HCuOs). This is a large and diverse superfamily that also has bacterial nitric oxide reductases (NOR) as a member. NORs form part of an anaerobic respiration pathway termed denitrification, where they reduce the toxic intermediate nitric oxide (NO) to nitrous oxide (N₂O). NORs can also be used for detoxification of NO produced by human macrophages, and the C-type HCuOs are the only terminal oxidases present in some pathogens such as Helicobacter pylori. There is a second major branch of terminal oxidases, the cytochrome bd oxidases, that are found solely in prokaryotes. Thus, these enzymes can be targeted for drug/antibiotics development. Our research aims at elucidating the structure-function relationship, assembly, cross-reactivity, energy conservation, proton transfer mechanisms and evolution of the NO and O₂-reducing terminal oxidases.

We are also involved in a collaboration project on 'The obligate respiratory supercomplex of Actinobacteria' funded by the Knut and Alice Wallenberg foundation, where we study both the HCuO branch and the cyt. bd branch of respiration in Mycobacterium smegmatis. See:

https://kaw.wallenberg.org/forskning/grundforskning-om-cellers-energifabriker-kan-bidra-till-nya-lakemedel