2015 - Structural and Functional Studies of NirC from Salmonella typhimurium
SURFE²R-technology (custom-built system) publication in Methods in Enzymology (2015)
Rycovska-Blume A., Lü W., Andrade S., Fendler K., Einsle O.
Methods in Enzymology (2015) 556:475-497
NirC is a pentameric transport system for monovalent anions that is expressed in the context of assimilatory nitrite reductase NirBD in a wide variety of enterobacterial species. A NirC pentamer contains individual pores in each protomer that mediate the passage of at least the nitrite (NO2-) and nitrate (NO3-) anions. As a member of the formate/nitrite transporter family of membrane transport proteins, NirC shares a range of structural and functional features with the formate channel FocA and the hydrosulfide channel AsrD (HSC). NirC from the enteropathogen Salmonella typhimurium has been studied by X-ray crystallography, proton uptake assays, and different electrophysiological techniques, and the picture that has emerged shows a fast and versatile transport system for nitrite that doubles as a defense system during the enteric life of the bacterium. Structural and functional assays are described, which shed light on the transport mechanism of this important molecular machine.