Figure 2.

Stability of λ O protein during the prepriming steps of λ DNA replication. The ³H-labeled λ O protein was incubated either alone (○) or with 400 ng oriλ DNA (•) or in the presence of oriλ DNA, λ P, and DnaB (▵). After a 3-min preincubation at 30°C, the ClpX and ClpP proteins were added. The reaction was stopped at the indicated time points, and the amount of ³H-labeled λ O hydrolyzed was estimated as described in Materials and Methods. The experiments were repeated with a greater amount of DNA (750 ng). The kinetics were similar except that the difference between O-some and preprimosome was not as prominent (result not shown).