E3 ubiquitin ligase catalyzing the covalent attachment of ubiquitin moieties onto substrate proteins. May operate on tyrosine-phosphorylated SRC substrates. S-ubiquitinyl-[E2 ubiquitin-conjugating enzyme]-L-cysteine + [acceptor protein]-L-lysine = [E2 ubiquitin-conjugating enzyme]-L-cysteine + N(6)-ubiquitinyl-[acceptor protein]-L-lysine. Protein modification; protein ubiquitination. Homodimer. Localized over the postacrosomal perinuclear theca region and the entire length of sperm tail. The HYB domain forms a phosphotyrosine-binding pocket upon dimerization, and mediates as well the recognition of its flanking acidic amino acids.