Chromatin silencing protein and pachytene checkpoint regulator Dot1p has amethyltransferase fold

Although protein methylation has been observed for decades, its functional significance has remained largely unclear. Using sensitive profile searches and structural modeling, chromatin silencing protein and meiotic recombina tion checkpoint regulator Dot1p was identified as a putative protein methyl transferase. Along with recent results that link histone H3 methylation wit h chromatin silencing, this finding suggests that an expanded combinatorial repertoire of protein modifications affects transcriptional regulation.