The Deltex family is responsible for influencing Notch signaling and may regulate transcription through interactions with specific transcription factors. Deltex proteins have a basic N-terminus, a central proline-rich region and a C-terminal RING-type zinc finger domain, a motif often found in ubiquitin-protein isopeptide ligases (E3). The RING-type zinc finger domain binds two Zn2+ atoms and forms a cross-brace motif that is essential for many proteins involved the ubiquitination pathway. DTX3L (Deltex-3-like), also known as BBAP, is a 740 amino acid protein that is similar to Deltex-3 and acts as a ubiquitin ligase in vitro. DTX3L can heterodimerize with Deltex-1, a transcriptional regulator, thereby enhancing the activity of the E3 ubiquitin ligase complex and increasing the influence of E3 on the Notch signaling pathway.