DTX3L ubiquitin ligase ubiquitinates single-stranded nucleic acids

• DOI: 10.7554/elife.98070
• Publication Date: 2024-07-08T14:25:09Z
• Authors: Emily L Dearlove; Chatrin Chatrin; Lori Buetow; Syed F Ahmed; Tobias Schmidt; Martin Bushell; Brian O Smith; Danny T Huang
• Keywords: RNA ligase; Ubiquitin-Protein Ligases

Ubiquitination typically involves covalent linking of ubiquitin (Ub) to a lysine residue on protein substrate. Recently, new facets this process have emerged, including Ub modification non-proteinaceous substrates like ADP-ribose by the DELTEX E3 ligase family. Here, we show that family member DTX3L expands substrate repertoire include single-stranded DNA and RNA. Although N-terminal region contains nucleic acid binding domains motifs, minimal catalytically competent fragment comprises C-terminal RING DTC (RD). DTX3L-RD catalyses ubiquitination 3'-end RNA, as well double-stranded with 3' overhang two or more nucleotides. This is reversibly cleaved deubiquitinases. NMR biochemical analyses reveal domain binds facilitates catalysis transfer from RING-bound E2-conjugated Ub. Our study unveils direct acids DTX3L, laying groundwork for understanding its functional implications.