Based on the prediction that histone lysine demethylases may contain the JmjC domain, we
examined the methylation patterns of five knock-out strains (ecm5Δ, gis1Δ, rph1Δ, jhd1Δ,
and jhd2Δ (yjr119cΔ)) of Saccharomyces cerevisiae. Mass spectrometry (MS) analyses of
histone H3 showed increased modifications in all mutants except ecm5Δ. High-resolution
MS was used to unequivocally differentiate trimethylation from acetylation in various tryptic
fragments. The relative abundance of specific fragments indicated that histones K36me3 …