The Hect domain is a protein structural motif found in various proteins, primarily involved in the regulation of cellular processes. It plays a crucial role in the ubiquitin-proteasome system, which tags proteins for degradation, thus maintaining cellular homeostasis and regulating protein levels. RLD 3 refers to a specific region within the Hect domain that is important for its function. This region is involved in the interaction with ubiquitin and other proteins, facilitating the transfer of ubiquitin molecules. Understanding RLD 3 is essential for insights into how the Hect domain contributes to cellular signaling and protein turnover.