OTU (ovarian tumor) domain of deubiquitinating enzyme OTU6 from plants and similar proteins
Deubiquitinating enzyme OTU6, also called OTU domain-containing protein 6 or otubain-like deubiquitinase 1 (OTLD1), is a deubiquitinase (DUB) or ubiquitin thiolesterase (EC 3.4.19.12) that catalyzes 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. OTU6 binds chromatin and has enzymatic histone deubiquitinase activity specific for the H2B histone. OTU6 belongs to the OTU family of cysteine proteases that use a conserved cysteine, histidine, and an aspartate, as the catalytic triad.