DUBA, also known as OTU domain-containing protein 5, is a de-ubiquitinating enzyme belonging to the OTU5 family and DUB subfamily characterized by an ovarian tumor (OTU) domain. DUBA is a protease that specifically cleaves ubiquitin linkages, negating the action of ubiquitin ligases. This de-ubiquitinating activity is directed towards 'Lys-63'-linked polyubiquitin chains and acts via TRAF3 de-ubiquitination and subsequent suppression of type I interferon (IFN) production. DUBA acts as a negative regulator of the innate immune system. It is generally inhibited by N-ethyl-maleimide (NEM). Expression of this enzyme is seen in various tissues, including the liver and placenta, as well as in peripheral blood leukocytes. DUBA is induced by bacterial lipopolysaccharides (LPS) in bone marrow-derived macrophages.