E6AP is an E3 ubiquitin ligase. Inheritance of a mutant maternal copy of this gene results in Angelman syndrome (AS) which is characterized by severe mental retardation, seizures, ataxia, and EEG abnormalities. E6AP interacts with the type 16 and 18 human papillomavirus E6 oncoprotein which results in the targeting of p53 for degradation via the ubiquitin-proteasome system.