The MoxR ATPase RavA and its cofactor ViaA interact with the NADH:ubiquinone oxidoreductase I in Escherichia coli.
MoxR ATPases are widespread throughout bacteria and archaea. The experimental evidence to date suggests that these proteins have chaperone-like roles in facilitating the maturation of dedicated protein complexes that are functionally diverse. In Escherichia coli, the MoxR ATPase RavA and its putative cofactor ViaA are found to exist in early stationary-phase cells at 37 °C at low levels of about 350 and 90 molecules per cell, respectively. Both proteins are predominantly localized to the cytoplasm, but ViaA was also unexpectedly found to localize to the cell membrane. Whole genome microarrays and synthetic lethality studies both indicated that RavA-ViaA are genetically linked to Fe-S cluster assembly and specific respiratory pathways. Systematic analysis of mutant strains of ravA and viaA indicated that RavA-ViaA sensitizes cells to sublethal concentrations of aminoglycosides. Furthermore, this effect was dependent on RavA's ATPase activity, and on the presence of specific subunits of NADH:ubiquinone oxidoreductase I (Nuo Complex, or Complex I). Importantly, both RavA and ViaA were found to physically interact with specific Nuo subunits. We propose that RavA-ViaA facilitate the maturation of the Nuo complex.
Department of Biochemistry, University of Toronto, Toronto, Ontario, Canada.
Keith S
KS
Wong
Department of Biochemistry, University of Toronto, Toronto, Ontario, Canada.
Jamie D
JD
Snider
Department of Biochemistry, Research and Innovation Centre, University of Regina, Regina, Saskatchewan, Canada.
Chris
C
Graham
Banting and Best Department of Medical Research, Terrence Donnelly Centre for Cellular and Biomolecular Research, University of Toronto, Toronto, Ontario, Canada.
Jack F
JF
Greenblatt
Banting and Best Department of Medical Research, Terrence Donnelly Centre for Cellular and Biomolecular Research, University of Toronto, Toronto, Ontario, Canada.
Andrew
A
Emili
Department of Biochemistry, Research and Innovation Centre, University of Regina, Regina, Saskatchewan, Canada.
Mohan
M
Babu
Department of Biochemistry, University of Toronto, Toronto, Ontario, Canada.
Walid A
WA
Houry
D000251:Adenosine Triphosphatases / Q000378:metabolism*; D000617:Aminoglycosides / Q000494:pharmacology; D042967:Electron Transport Complex I / Q000378:metabolism*; D004926:Escherichia coli / Q000187:drug effects / Q000201:enzymology*; D029968:Escherichia coli Proteins / Q000378:metabolism*; D005453:Fluorescence; D005978:Glutathione / Q000494:pharmacology; D047468:Immunoprecipitation; D007612:Kanamycin / Q000494:pharmacology; D008826:Microbial Sensitivity Tests; D018384:Oxidative Stress
D000617:Aminoglycosides; D029968:Escherichia coli Proteins; D007612:Kanamycin; D000251:Adenosine Triphosphatases; C508688:RavA protein, E coli; D042967:Electron Transport Complex I; D005978:Glutathione