FIGURE 4.
RapLS20 binds to Rco and inhibits the DNA binding activity of Rco, whereas PhrLS20 relieves the inhibitory effect of RapLS20. A, in vitro interaction of RapLS20 and Rco. Size exclusion chromatography of RapLS20 (20 μm), Rco (40 μm), and RapLS20-Rco in complex (20 and 40 μm) was performed on a Superdex 200 10/300 GL column. Top, chromatograms; bottom, SDS-PAGE analysis of the eluted fractions. B, PhrLS20 binds to RapLS20. The addition of 40 μm PhrLS20 to 20 μm RapLS20 changes the elution profile of RapLS20. C, the addition of 40 μm PhrLS20 disrupts complex formation of RapLS20 and Rco (20 and 40 μm). D, top, RapLS20 inhibits DNA binding activity of Rco; bottom, PhrLS20 relieves the inhibitory effect of RapLS20 on DNA binding activity of Rco. Rco was mixed with RapLS20 and PhrLS20 at the indicated concentrations prior to the addition of 50 nm PUTR.