Molecular and functional properties of the Na+ -translocating NADH:quinone oxidoreductase (Na+ -NQR) from Vibrio cholerae

• Applicant: Professorin Dr. Julia Fritz-Steuber
• Subject Area: Metabolism, Biochemistry and Genetics of Microorganisms
• Term: from 2011 to 2017
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 212191952

The bacterium Vibrio cholerae, the causative agent of Cholera disease, utilizes the Na+-translocating NADH:quinone oxidoreductase (Na+-NQR) to generate a Na+ motive force. The Na+-NQR is a membrane-bound enzyme complex consisting of the six subunits NqrABCDEF. This redox-driven pump with a molecular mass of 220 kDa catalyzes the first step in the respiratory chain of V. cholerae and couples the exergonic oxidation of NADH to the endergonic translocation of Na+ from the cytoplasm to the periplasm. The mechanism of redox-driven Na+ transport by the Na+-NQR is unknown. Our long-term goal is to understand this process at atomic scale. To this end, we will analyze the electron transfer and Na+ translocation events using the solubilized and reconstituted pump, and characterize and crystallize subcomplexes for the determination of the 3D structure.

• DFG Programme: Research Grants