Figure 2.

RNA polymerase forms a complex with the DNA-bound λO protein. Association of the host RNAP holoenzyme with λO nucleoprotein complex was estimated by SPR technique. Biotinylated DNA containing four iterons present at oriλ was immobilized on a sensor chip. Subsequently, a 5-min injection of λO protein (50 nM) was performed followed by a 5-min injection of RNAP (25 nM) or BSA and a change of protein mass on the sensor was monitored. In the next step, dissociation was monitored by running a buffer over the sensor chip surface (15 µl/min flow speed). Data were evaluated using Biacore AB’s BIA evaluation software. The presented sensogram reflects results obtained after subtraction of the background response signal and correction of the buffer effect.