... of the catalytic Hect ubiquitin ligase domain( Fig. 2 ). The EEL-1 protein has an overall configuration similar to the mammalian E3 ligase Mule. Known in vivo targets of Mule ubiquitination include the tumor suppressor p53 (also known as Trp53), the transcription factor Myc, and the anti-apoptotic protein Mcl1...