5V1Y:
reference: Structure and energetics of pairwise interactions between proteasome subunits RPN2, RPN13, and ubiquitin clarify a substrate recruitment mechanism., VanderLinden RT, Hemmis CW, Yao T, Robinson H, Hill CP, J Biol Chem. 2017 Apr 25. pii: jbc.M117.785287. doi: 10.1074/jbc.M117.785287. PMID: 28442575

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