PROSITE documentation PDOC51917

Pru (pleckstrin-like receptor for the Ub) domain profile

In eukaryotes, selective protein degradation is performed primarily by the ubiquitin–proteasome pathway, in which substrate proteins are marked by covalently attached ubiquitin chains that mediate recognition by the proteasome. Rpn13 (also called ADRM1) is a subunit of the proteasome that serves as a receptor for both ubiquitin and Uch37, one of the proteasome's three deubiquitinating enzymes. Rpn13 binds ubiquitin though a conserved amino-terminal region termed the pleckstrin-like receptor for the Ub (Pru) domain (also known as the ubiquitin-binding domain, or UBD), which binds K48-linked diubiquitin. Its carboxy-terminal DEUBAD domain (see <PDOC51916>) binds deubiquinating enzyme Uch37/UCHL5 and enhances its isopeptidase activity [1,2,3].

The Pru domain forms two contiguous, antiparallel β-sheets with a configuration similar to the pleckstrin-homology structural domain: a four-stranded twisted antiparallel β-sheet (β 1, 4-6) packs almost orthogonally against a second triple stranded β-sheet (β 7-8). Juxtaposed to the three-stranded sheet are two β-strands (β 2-3). The Pru domain forms a hydrophobic core containing conserved hydrophobic residues, which are located within β-sheets. One end of the β-sandwich is capped by a long C-terminal amphipatic α-helix (see <PDB:2R2Y>) [1,2,3].

The profile we developed covers the entire Pru domain.