Figure 2.

Molecular Consequences of Treatment of S. solfataricus with HU

(A) Western blot analysis of the levels of a variety of replication and cell division-associated proteins in Sulfolobus following treatment with 10 mM HU for 7 hr. The anti-WhiP antisera detects full-length protein and an additional truncated form. Loading for all panels was confirmed by western blotting for the general transcription factor, TBP. A single representative TBP panel is shown.

(B) Flow cytometry profile confirming the cell cycle arrest upon HU treatment for the cells used in (A).

(C) Western blot analyses of the effect of 7 hr exposure to the indicated concentrations of HU on the levels of Orc1-1, Orc1-3, and primase subunits. Flow cytometry profiles of the cells following treatment are shown on the right. TBP serves as a loading control in this and the subsequent panel.

(D) Effect of varying the time of exposure to 10 mM HU on the levels of Orc1-1, Orc1-3, and primase subunits. Flow cytometry profiles of the treated cells are shown to the right of the western blot images.