Figure 4.

Hfq binds single- and double-stranded RNAs as well as RNAs of different GC-contents with different affinities as determined with MST. (A) Representative normalized fluorescence curves of an MST experiment using Cy5-J1 and a titration series of Hfq. Importantly, the RNA molecules move from warm to cold areas as indicated by the fluorescence decrease after the laser has been switched on. Notably, at Hfq₆ concentrations of about 800–1600 nM the contrary behavior (molecules moving toward warm areas) or a superimposing effect was visible. (B) From the MST experiments the T jump signal F_{norm,T jump} was derived for all single-stranded RNAs. Unfilled circles represent values that stem from curves showing the superimposing effect (se). (C) From the MST experiments the T jump signal F_{norm, T jump} was derived for all double-stranded RNAs.