Projekt

Graduate School Protein Complex Assembly (PROCOMPAS): Maturation of nitrite reductase NirS through interaction with NirF and NirN

The insertion of complex cofactors into enzymes often requires helper proteins that not only participate in the insertion process itself but may also be involved in biosynthesis and transport of these molecules. Nitrite reductase NirS, a central enzyme in nitrate respiration of microorganisms including pathogens such as Pseudomonas aeruginosa, contains two types of heme cofactors, namely a heme c and a heme d1. While heme c depends on the well-studied cytochrome c maturation system, much less is known about the processing of heme d1. Previous work in our groups has shown that heme d1 is escorted and processed by NirF and NirN, who not only organize its insertion into NirS but are also involved in a terminal oxidation step. Work in this project entails structure determination of these proteins and of their complexes as well as their biophysical characterization.