OTU (ovarian tumor) domain of deubiquitinating enzymes OTU3 and OTU4 from plants, and similar proteins
Deubiquitinating enzyme OTU3 (also called OTU domain-containing protein 3) and deubiquitinating enzyme OTU4 (also called OTU domain-containing protein 4) are deubiquitinases (DUBs) or ubiquitin thiolesterases (EC 3.4.19.12) that catalyze the thiol-dependent hydrolysis of ester, thioester, amide, peptide and isopeptide bonds formed by the C-terminal Gly of ubiquitin, a small regulatory protein that can be conjugated to a large range of target proteins. Protein ubiquitination is a post-translational modification of mostly Lys residues that regulates many cellular processes, including protein degradation, intracellular trafficking, cell signaling, autophagy, transcription, translation, and the DNA damage response. OTU3 and OTU4 may play important regulatory roles at the level of protein turnover by preventing degradation. They belong to the OTU family of cysteine proteases that use a conserved cysteine, histidine, and an aspartate, as the catalytic triad.
Jiyao W et al.(2023). "The conserved domain database in 2023.",