FIGURE 1.

PLAA harbors a central region that putatively interacts with Ub. A, domain architecture of PLAA. WD40, WD40 repeats; PUL, PLAA, UFD3, and LUB1 conserved domain; UIM, ubiquitin-interacting motif. B, multiple sequence alignment of the PFU domain from different species. C, the putative UIM sequence has the conserved residues Glu, Leu, Ala, and Ser as marked by asterisks. S5a, S5a subunit of proteasome; At3, ataxin-3. D, GST pulldown assay for the central region of PLAA (residues 312–465, UIM-PFU) binding with Ub. The products pulled down from 293T cell lysate were detected by Western blotting with an anti-Ub antibody.