OTU (ovarian tumor) domain of deubiquitinating enzyme OTU5 from plants and similar proteins
Deubiquitinating enzyme OTU5, also called OTU domain-containing protein 6, 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. OTU5 is an inactive cysteine protease. It regulates gene expression by contributing to chromatin organization and DNA methylation patterns (e.g. H3K4me3 and H3K27me3). It is required for phosphate (Pi) homeostasis. OTU5 belongs to the OTU family of cysteine proteases that use a conserved cysteine, histidine, and an aspartate, as the catalytic triad.