This is the ubiquitin carboxyl-terminal hydrolase domain found in a variety of proteins, including PAN2, one of the subunits of the poly(A)-specific nuclease (PAN) is a deadenylating enzyme involved in cytoplasmic mRNA turnover (consisting of PAN2 and PAN3), involved in the initial trimming of poly(A) tails [1-3].

1: The yeast Pan2 protein is required for poly(A)-binding protein-stimulated poly(A)-nuclease activity. Boeck R, Tarun S Jr, Rieger M, Deardorff JA, Muller-Auer S, Sachs AB; J Biol Chem. 1996;271:432-438. PMID:8550599

2: An asymmetric PAN3 dimer recruits a single PAN2 exonuclease to mediate mRNA deadenylation and decay. Jonas S, Christie M, Peter D, Bhandari D, Loh B, Huntzinger E, Weichenrieder O, Izaurralde E; Nat Struct Mol Biol. 2014;21:599-608. PMID:24880343

3: The structure of the Pan2-Pan3 core complex reveals cross-talk between deadenylase and pseudokinase. Schafer IB, Rode M, Bonneau F, Schussler S, Conti E; Nat Struct Mol Biol. 2014;21:591-598. PMID:24880344