E3 ubiquitin-protein ligase required to prevent centriole reduplication (By similarity). Probably acts by ubiquitinating positive regulators of centriole reduplication (By similarity). Mediates monoubiquitination of 'Lys-119' of histone H2A (H2AK119Ub), a specific tag for epigenetic transcriptional repression: associates with some Polycomb group (PcG) multiprotein PRC2-like complex and mediates repression of target genes (PubMed:25470042). {By
SimilarityUniProtKB:O94972, Experimental EvidencePubMed:25470042}.