Description
A subunit of the 26S proteasome, S5a, recognises and binds multi-ubiquitinylated proteins containing chains of at least four ubiquitin moieties. Purified recombinant S5a retains the ability to bind multi-ubiquitinylated proteins in isolation, when immobilised on glutathione-Sepharose, and after being eluted from glutathione-Sepharose, run on SDS-PAGE, and blotted onto nitrocellulose. Human S5a sequence, with an N-terminal fusion of glutathione S-transferase (Schistosoma japonicum), was expressed in E. coli with GST tag at amino terminus