2Z4D:
reference: Proteasome subunit Rpn13 is a novel ubiquitin receptor., Husnjak K, Elsasser S, Zhang N, Chen X, Randles L, Shi Y, Hofmann K, Walters KJ, Finley D, Dikic I, Nature. 2008 May 22;453(7194):481-8. PMID: 18497817

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