The UBP-type zinc finger was first isolated in some members of a subfamily of deubiquitinating enzyme, the ubiquitin-specific processing protease (UBP) (see <PDOC00750>). HDAC6 UBP-type zinc finger has been shown to interact with ubiquitin [1,2]. Like with other ubiquitin binding domain (UBD) the interaction with ubiquitin is moderate or even weak. In addition, several UBD families have members that do not interact with ubiquitin at all, which emphasis that binding domains that are identified by similarity searches should be experimentally verified [3].

Some proteins containing an UBP-type zinc finger are listed below:

• BRCA1-associated protein 2 (BRAP2). It binds the nuclear localization signal of BRCA1.
• Animal histone deacetylase 6 (HDAC6). An atypical deacetylase that contains two functional catalytic domains. HDAC6 shuttles in and out of the cell nucleus. In the cytoplasm it is part of a multiprotein complex involved in the control of protein ubiquitination.
• Various eukaryotic deubiquitinating enzymes of the UBP subfamily.
• A small family of uncharacterized bacterial proteins found in Actinobacteria, Proteobacteria, Cyanobacteria and Acidobacteria.

The profile we developed covers the whole UBP-type zinc finger.