Otubain 1 (Otub1) is a member of the OTU class of ubiquitin isopeptidases. It was originally identified as a protein capable of binding ubiquitin aldehyde. Researchers have shown that it is able to cleave K48-linked ubiquitin chains in vitro. Otubain 1 has been shown to be involved in T cell function and is a substrate for Yersinia protein kinase.
