protein) is an E3 (ubiquitin protein ligase) that is involved in the
conjugation of ubiquitin to target substrates along with E1 and E2 enzymes. It
is a HECT domain E3 containing an active site cysteine which accepts a charged
ubiquitin from the ubiquitin-E2 thiolester complex. E6-AP has been linked to a
neurodevelopmental disorder, Angelman syndrome. In addition, the oncoprotein E6
of human papillomaviruses (HPV) utilizes E6-AP to target numerous cellular
proteins for degradation including the tumor suppressor protein p53.