摘要：SummaryPolycomb Repressive Complex 2 (PRC2) catalyzes the mono-, di-, and trimethylation of histone protein H3 on lysine 27 (H3K27), which is strongly associated with transcriptionally silent chromatin. The functional core of PRC2 is highly conserved in animals and consists of four subunits. One of these, SUZ12, has not been identified in the genetic modelCaenorhabditis elegans, whereasC. elegansPRC2 contains the clade-specific MES-3 protein. Through unbiased sensitive sequence similarity searches complemented by high-quality structure predictions of monomers and multimers, we here demonstrate that MES-3 is a highly divergent ortholog of SUZ12. MES-3 shares protein folds and conserved residues of key domains with SUZ12 and is predicted to interact with core PRC2 members similar to SUZ12 in human PRC2. Thus, in agreement with previous genetic and biochemical studies, we provide evidence thatC. eleganscontains a diverged yet evolutionary conserved core PRC2, like other animals.Graphical abstractDisplay OmittedHighlights•The canonical PRC2 component SUZ12 was seemingly absent inCaenorhabditis elegans•Sensitive similarity searches and structure prediction unearth hidden homology•C. elegansMES-3 is a highly divergent ortholog of SUZ12•MES-3 interacts with coreC. elegansPRC2 subunits, resembling SUZ12 in human PRC2Biochemistry; Protein; Bioinformatics; 3days reconstruction of protein; Sequence homology
