  FoF1-ATP synthases are membrane-embedded protein machines that catalyze the
synthesis of adenosine triphosphate. Using photoactivation-based localization
microscopy (PALM) in TIR-illumination as well as structured illumination
microscopy (SIM), we explore the spatial distribution and track single FoF1-ATP
synthases in living E. coli cells under physiological conditions at different
temperatures. For quantitative diffusion analysis by mean-squared-displacement
measurements, the limited size of the observation area in the membrane with its
significant membrane curvature has to be considered. Therefore, we applied a
'sliding observation window' approach (M. Renz et al., Proc. SPIE 8225, 2012)
and obtained the one-dimensional diffusion coefficient of FoF1-ATP synthase
diffusing on the long axis in living E. coli cells.
