Transcriptional regulator that acts via the formation of large multiprotein complexes that modify and/or remodel the chromatin. Required for both gene activation and repression. Part of the Set3C complex, which is required to repress early/middle sporulation genes during meiosis. Required for the transcriptional activation of genes with high activity (By similarity). Belongs to the class V-like SAM-binding methyltransferase superfamily. Histone-lysine methyltransferase family. SET3 subfamily.