2G43: Structure Of The Znf Ubp Domain From Deubiquitinating Enzyme Isopeptidase T (Isot)

Ubiquitin binding proteins regulate the stability, function, and/or localization of ubiquitinated proteins. Here we report the crystal structures of the zinc-finger ubiquitin binding domain (ZnF UBP) from the deubiquitinating enzyme isopeptidase T (IsoT, or USP5) alone and in complex with ubiquitin. Unlike other ubiquitin binding domains, this domain contains a deep binding pocket where the C-terminal diglycine motif of ubiquitin is inserted, thus explaining the specificity of IsoT for an unmodified C terminus on the proximal subunit of polyubiquitin. Mutations in the domain demonstrate that it is required for optimal catalytic activation of IsoT. This domain is present in several other protein families, and the ZnF UBP domain from an E3 ligase also requires the C terminus of ubiquitin for binding. These data suggest that binding the ubiquitin C terminus may be necessary for the function of other proteins.
PDB ID: 2G43Download
MMDB ID: 38386
PDB Deposition Date: 2006/2/21
Updated in MMDB: 2007/10
Experimental Method:
x-ray diffraction
Resolution: 2.09  Å
Source Organism:
Similar Structures:
Biological Unit for 2G43: monomeric; determined by author
Molecular Components in 2G43
Label Count Molecule
Protein (1 molecule)
Ubiquitin Carboxyl-terminal Hydrolase 5(Gene symbol: USP5)
Molecule annotation
Chemical (1 molecule)
* Click molecule labels to explore molecular sequence information.

Citing MMDB