Fig. 1

Single amino acid substitutions expressed at both HHT1-HHF1 and HHT2-HHF2 strongly derepress SER3. Northern blot analysis examining the effect of histone mutants on SER3, SRG1, and SCR1 (loading control). Total RNA was isolated from yeast strains that were grown to a density of 1–2 × 10⁷ cells/mL in media with or without serine at 30 °C. All yeast strains were derivatives of JDY86 expressing either synthetic WT copies of histone H3 at both genomic locations (YS417) or mutants hhts-K122A (YS404), hhts-Q120A (YS409), hhts-R49A (YS428), also expressed at both genomic locations