National Center for
3WUP: Crystal Structure Of The Ubiquitin-binding Zinc Finger (ubz) Domain Of The Human Dna Polymerase Eta
FEBS J. (2016) 283 p.2004-2017
The ubiquitin-binding zinc finger (UBZ) is a type of zinc-coordinating beta-beta-alpha fold domain found mainly in proteins involved in DNA repair and transcriptional regulation. Here, we report the crystal structure of the UBZ domain of Y-family DNA polymerase (pol) eta and the crystal structure of the complex between the UBZ domain of Werner helicase-interacting protein 1 (WRNIP1) and ubiquitin, crystallized using the GFP fusion technique. In contrast to the pol eta UBZ, which has been proposed to bind ubiquitin via its C-terminal alpha-helix, ubiquitin binds to a novel surface of WRNIP1 UBZ composed of the first beta-strand and the C-terminal alpha-helix. In addition, we report the structure of the tandem UBZ domains of Tax1-binding protein 1 (TAX1BP1) and show that the second UBZ of TAX1BP1 binds ubiquitin, presumably in a manner similar to that of WRNIP1 UBZ. We propose that UBZ domains can be divided into at least two different types in terms of the ubiquitin-binding surfaces: the pol eta type and the WRNIP1 type. DATABASE: Structural data are available in the Protein Data Bank under accession numbers 3WUP (pol eta UBZ), 3VHS (WRNIP1 UBZ), 3VHT (GFP-WRNIP1/ubiquitin), 4Z4K (TAX1BP1 UBZ1 + 2), and 4Z4M (TAX1BP1 UBZ2).