UBE3A (also known as E6-AP) is an E3 ubiquitin-protein ligase which accepts ubiquitin from an E2 ubiquitin-conjugating enzyme in the form of a thioester and transfers it to its substrates. It regulates cell proliferation by promoting proteasomal degradation of p27 []. It can also serve as a molecular circadian clock through regulating the BMAL1 transcription factor [].
The AZUL or amino-terminal zinc-binding domain of ubiquitin E3a ligase (Ube3A) is found in eukaryotes, and is an unusual zinc-finger domain. The final cysteine is usually mutated in Angelman syndrome patients. It is likely that AZUL plays a role in Ube3A substrate-recognition [].
The AZUL or amino-terminal zinc-binding domain of ubiquitin E3a ligase (Ube3A) is found in eukaryotes, and is an unusual zinc-finger domain. The final cysteine is usually mutated in Angelman syndrome patients. It is likely that AZUL plays a role in Ube3A substrate-recognition [].The AZUL domain has a helix-loop-helix architecture with a Zn ion coordinated by four Cys residues arranged in Cys-X(4)-Cys-X(4)-Cys-X(28)-Cys motif [].
