Description
Enables identical protein binding activity and ubiquitin-ubiquitin ligase activity. Involved in several processes, including DNA damage checkpoint signaling; cellular protein metabolic process; and mRNA splicing, via spliceosome. Acts upstream of or within protein polyubiquitination. Located in cytoplasm; nuclear speck; and site of double-strand break. Part of Prp19 complex and U2-type catalytic step 2 spliceosome. Colocalizes with DNA replication factor A complex.