Separation of fork arresting and silencing activities in the S. cerevisiae Fob1 I407T mutant. A, silencing of mURA3 in the fob1Δ strain containing vector (pGAD424), S. cerevisiae Fob1 (ScFob1), and its I407T derivative. B and C, two-hybrid interactions of S. cerevisiae Fob1 or its I407T derivative with S. cerevisiae Net1 and S. cerevisiae Sir2, respectively. D and E, β-galactosidase assay of yeast two-hybrid interactions of S. cerevisiae Fob1 and S. cerevisiae Fob1 mutant I407T with S. cerevisiae Net1 and S. cerevisiae Sir2, respectively. F, two-dimensional agarose gel analysis of replication intermediates from fob1Δ of YSB348 containing vector (pGAD424), pGAD424 S. cerevisiae FOB1, or pGAD424-FOB1I407T.