FIG. 1.

Rfm1 is required for MSE-mediated repression. The fold repression of the MSE-lacZ promoter reporter in each strain background is presented as a ratio of β-galactosidase activity of the reporter lacking an MSE, pAV124 (50 U in the wild-type [WT] strain), compared to activity of a reporter that contains an MSE, pJX43 (0.4 U in the wild-type strain). Repression was measured in the wild type (W303-1A), in the sum1Δ mutant (JXY3), in the hst1Δ mutant (JXY5), in the rfm1Δ mutant (MPY13), in the hst1Δ rfm1Δ mutant (RMY8), in the rfm1Δ mutant (MPY13) transformed with pRAM15 (2μm HST1), and in the hst1Δ mutant (JXY5) transformed with pSW106 (2μm RFM1).